1 LITHUANIAN UNIVERSITY OF HEALTH SCIENCES
ACADEMY OF MEDICINE FACULTY OF PUBLIC HEALTH
Maitri Pradip Upadhyay
DETERMINANTS OF VITAMIN D DEFICIENCY IN PATIENTS WITH BONE DISORDERS IN INDIA
Master thesis (Applied Public Health)
Student
Maitri Pradip Upadhyay
Supervisor Prof. Dr. Janina Petkevičienė
KAUNAS, 2020
2
SUMMARY
Applied Public Health
DETERMINANTS OF VITAMIN D DEFICIENCY IN PATIENTS WITH BONE DISORDERS IN MUMBAI.
Maitri Pradip Upadhyay
Scientific Supervisor Prof. Dr. Janina Petkevičienė
Lithuanian University of Health Sciences, Faculty of Public Health, Department of Preventive Medicine.
Kaunas, 2019; 63 p.
Aim: To assess the factors associated with vitamin D deficiency in patients with bone disorders in Mumbai.
Objectives: 1) to identify sociodemographic characteristics, skin colour and clothing of the patients; 2) to assess nutrition habits, use of supplements and sun exposure of the participants; 3) to examine the self- assessed health and vitamin D status of the respondents, 4) to evaluate associations between analysed factors and vitamin D deficiency.
Methods: A cross-sectional study was carried out in three hospitals in Mumbai (India). Patients visiting a doctor because of complaints of bone weakness, joint pain, and muscle pain were asked to fill in the original questionnaire. In total, 86 (43%) men and 114 (57%) women participated in the study. The questionnaire consisted of 27 questions about sociodemographic characteristics, skin colour, clothing, nutrition habits, use of supplements, sun exposure and self-assessed health of the participants. Serum 25- hydroxyvitamin D level was measured. The level <30 ng/ml was considered as low. For statistical data analysis, the Chi square (χ2) criteria, z test with Bonferroni correction, Student t test and one-way ANOVA test were applied.
Results. Most of the respondents were younger than 40 years old, married, having professional or university education, and being from the middle class. The majority of participants had white or white to light brown skin and reported wearing all type of clothes. The diet of men was healthier than women.
Daily consumption of fresh vegetables was reported by 39.5% of men and only 15.8% of women. Nuts,
legumes and seeds were consumed daily by 22.1% of men and 2.6% of women. Fish was consumed at
least 4 times a week by 41.7% of men and by 22.9% of women. More men than women consumed milk
and dairy products daily. The older respondents and women preferred a lactovegetarian diet, while
younger respondents and men consumed a mixt diet more often. The intake of dietary supplements
including vitamin D were reported by women and older respondents more often than by men and younger
individuals. More women (56.1%) than men (34.9%) used sunscreen. The highest proportion of
3 respondents (70.0%) reported 15-30 min of daily sun exposure per week. The majority of respondents (89.5%) assessed their health status as good or reasonably good. All respondents had serum vitamin D level less than 30 ng/ml (mean value 24.4 ng/ml). Serum vitamin D level <20 ng/ml was found in 15.8%
of respondents. The associations of serum vitamin D level with sociodemographic characteristics and lifestyle factors were analysed.
Conclusions: Only a few statistically significant associations have been found between serum vitamin D level and analysed factors. Younger respondents and those having suntan had lower serum vitamin D level than older and not reporting suntan respondents. Low BMI was associated with a lower level of serum vitamin D. With improving the economic status and increasing milk consumption, the tendency of the increase in serum vitamin D level was observed.
Keywords: vitamin D, deficiency, sociodemographic characteristics, lifestyle factors
4
CONTENT
Acknowledgment………...5
List of abbreviations 6
Scientific terms 7
Introduction 8
Aim and objectives………..……...…..10
1. Literature review 11
1.1 The prevalence of vitamin D deficiency………...….11
1.2 Risk factors of vitamin D deficiency………...…….13
1.2.1 The role of sun exposure………...….13
1.2.2 Dietary risk factors of vitamin D deficiency………...……...17
1.2.3 Supplementation of vitamin D deficiency………...……...20
2. Material and methods 23
2.1 Study design and sample………...………...23
2.2 Research instrument and variables………23
2.3 Statistical analysis……….……...24
3. Results ………...………...…...25
3.1 Sociodemographic factors, skin colour and clothing of study population 25
3.2 Food habits, the use of supplements and sun exposure of the participants 27
3.3 The self-assessed health and vitamin D status of the respondents 38
3.4 Associations between serum vitamin D level, sociodemographic and lifestyle variables 40
4. Discussion 51
Conclusions ……….56
Practical recommendation………57
References………....58
Annex 1………...64
Annex 2………65
5
Acknowledgement
It is time of gratification and pride to look back with a sense of satisfaction on this long journey;
with all my heart I want to thank each one of them. Many people have played a role in allowing me to give my thesis a concrete form. Time and space constraints prevent all of them here from being mentioned. First and foremost I give thanks to the all-knowing, all-present, all-powerful, GOD who has always sponsored myself with controversy and love.
Words are insufficient to convey my profound sense of thankfulness. I sincerely feel that my Father Mr. Pradip M. Upadhyay must have all credits for his consistent prayer, loving blessing, self- satisfaction and an unending trust in me. I sincerely believe that I would never have arrived at the stage of writing this recognition without my family's support. I am grateful to the honourable mother Mrs.
Meena P. Upadhyay who always gives me strength and inspiration and sincerely aspires to see me pursue higher education. I am grateful for this opportunity wholehearted.
Friendship is always a good thing and never a chance. My deepest feeling of debt towards my best friends is difficult for me. Thanks for always listening, supporting and encouraging me. I thank you all, my best friends Kush, Kruti, Dharam, Sagar, Anshul, Charlie, Ajhinkya, Dr. Ruhi and Dr. Rajesh Badiyani As a friend of yours, my life has added bright spots.
I am indebted to the deep inspirer my esteemed guide Prof. Dr. Janina Petkevičienė, Department of Preventive Medicine. Her words of advice have been etched in my heart and I will always endeavour to hold up her ideas. Her simplicity, untiring and meticulous guidance, caring attitude be cherished in all walks of my life. I thank for bringing out the besting me.
Dr. Maitri Pradip Upadhyay
6
List of abbreviations
25(OH)D – 25 Hydroxyvitamin D ANOVA – Analysis of variance BMI – Body mass index
FAO – Food and Agriculture Organization FGF23 - Fibroblast Growth Factor 23 FNB – Food Nutrition Board
ICMR – Indian Council of Medical Research IOM – Institute of Medicine
IU – International unit
MED – Minimal erythemal dose PTH – Parathyroid hormone
RDA – Recommended Daily Allowance SD – Standard deviation
SHPT – Secondary hyperparathyroidism
SPSS - Statistical Product and Service Solutions UAE – United Arab Emirates
USA – United States of America UV – Ultra violet rays
UVB – Ultraviolet B-rays
VDD – Vitamin D deficiency
WHO – World Health Organization
7
Scientific terms
Calcification – accumulation of calcium salts in body tissues
Calcium homeostasis – function to maintain constant concentration of calcium ions in the extra cellular fluids
Catabolism – it is a set of metabolic pathways that break downs molecules into smaller units that are either oxidize to release energy or used in other anabolic reaction
Fibroblast growth factor 23 – Plays a role of regulation of phosphate concentration in plasma Hypercalcemia – condition in which calcium level in blood above normal
Hyperparathyroidism – increase in parathyroid hormone (PTH) level in blood
Hyperphosphatemia – an electrolyte disorder in which there is an elevated level of phosphate in the blood
Kuppuswamy scale – socioeconomic status scale
Nephrocalcinosis – calcium level in kidneys is increased Osteoblast – cell that makes bone
Osteoclast – large multinucleated bone cell which absorb bone tissue during growth and healing Osteomalacia – softening of bones due to vitamin D deficiency
Osteoporosis - bones become weak and brittle
8
Introduction
The relevance of the problem.
A function for vitamin D was first documented in bone health in the 1920s when McCollum and colleagues developed a diet-induced rickets model for rats. Vitamin D has various functions in the human body [1]. In humans, there are two significant types of vitamin D: vitamin D3 and vitamin D2. The primary role of vitamin D is to regulate the balance of calcium and phosphorus which promote healthy bony tissue development. It is important for the homoeostasis of calcium and for musculoskeletal health [1]. Deficiency of vitamin D and calcium can cause low bone mass and muscle fatigue and may contribute to increased risk of osteoporotic fracture. Vitamin D also has a role in immune systems [2]. Extreme lack of vitamin D may cause different infections. For children, severe insufficiency in vitamin D contributes to osteomalacia [3].
Vitamin D can be acquired in the human body in three ways: through the skin, through normal food intake, and through supplements [1]. When in touch with intense sunlight the human body develops vitamin D.
Around 1 billion individuals globally are deficient in vitamin D, while 50% of the population is lacking in vitamin D [4]. The prevalence of vitamin D deficiency is higher in the elderly [5]. Vitamin D deficiency can be linked to populations with higher rates of skin melanin and who use comprehensive skin coverage, particularly in Middle Eastern countries. About 35% of the population in the United States are deficient in vitamin D, while more than 80% of people in Pakistan, India and Bangladesh are deficient in vitamin D [4,5]. In the United States, 61% of the elderly population is deficient in vitamin D, while 90% are deficient in Turkey, 96% in India, 72% in Pakistan and 67% in Iran [4].
Few food products have a higher amount of vitamin D naturally, and diets that are not supplemented with vitamin D are frequently insufficient to satisfy the vitamin D needs of an individual [6]. Factors such as sun exposure time, amount of skin exposed, latitude, air quality, skin pigmentation, clothes, usage of sunscreen, eating only vegetarian food, may contribute to hypovitaminosis D [7,8].
Indian diet usually does not fulfil an average adult's regular need for vitamin D [9,10]. People's
eating preferences primarily comprise vegetarian and dairy, rather than non-vegetarian. In India, vitamin
D is seldom used to fortify commonly eaten food products such as dairy products. Indian socio-religious
and cultural rituals and social taboos influence the individual's lifestyle [11]. Because of national
clothing, some individuals do not get enough sun exposure and thereby counteract the advantages of
plentiful sunlight. As a result, the deficiency of subclinical vitamin D is extremely prevalent both in urban
and rural settings and in both social and regional strata [12].
9 Mumbai has a warm, tropical atmosphere. The environment of Mumbai can best be characterized as humbly hot and humid. A large number of people in Mumbai are vegetarians and enjoy their local food very much. Given the long hours of sunlight, vitamin D deficiency is prevalent in Mumbai. Busy lifestyle holds people indoors or inside the car at sunlight peak period between 11 a.m. and 3 p.m. Almost nobody gets clear access to the sun on the entire body, not even for 10 minutes. A study found the prevalence of vitamin D deficiency of 87% in Mumbai [13].
The aim of this study was to assess the factors associated with vitamin D deficiency in patients with bone disorders in Mumbai (India).
Scientific novelty
The study was conducted using the original questionnaire. It contained several questions to determine the causes of having vitamin D deficiency in the selected population of patients with bone weakness, joint pain, and muscle pain. The dietary patterns, the usage of vitamin D supplements, sun exposure, and other factors were analysed in relation to vitamin D level.
Practical significance
The study found a very high prevalence of vitamin D deficiency in patients with bone disorders.
The study data revealed unhealthy diet, low sun exposure, insufficient use of vitamin D supplements in patients, which may cause lack of vitamin D. The data can be used for the development of recommendations for the prevention of vitamin D deficiency.
Author's contribution
The author developed a questionnaire, received the permission of Bioethics Committee to
perform the study, organized the study in hospitals of Mumbai, entered the data to a computer database,
performed the statistical analysis, and summarized the data in the master thesis.
10
The aim of the study :
To assess the factors associated with vitamin D deficiency in patients with bone disorders in Mumbai (India).
Objectives:
1. To identify sociodemographic characteristics, skin colour and clothing of the patients.
2. To assess nutrition habits, use of supplements and sun exposure of the participants.
3. To examine the self-assessed health and vitamin D status of the respondents.
4. To evaluate associations between analysed factors and vitamin D deficiency.
11
1. Literature review
1.1. The prevalence of vitamin D deficiency
Vitamin D retains sufficient amounts of serum calcium and phosphate to enable proper bone mineralization and to avoid hypocalcaemia. Osteoblasts and osteoclasts often use calcium for bone development and bone remodelling [8,14]. Vitamin D have 2 types, namely, ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3).
Serum 25-hydroxy Vitamin D level above 30 ng/ml has been generally recognized as being optimal for the biological activities of vitamin D [15]. Some investigators have chosen their own cut-off ranges of 25(OH)D level: the vitamin D deficiency is described as 25(OH)D<20 ng/ml; 20–29 ng/ml - insufficiency and ≥30 ng/ml sufficient level [8].
Vitamin D deficiency is pandemic, most under-diagnosed and under-treated nutritional deficiency in the world. Vitamin D deficiency is widespread in individuals irrespective of their age, gender, race and geography. Vitamin D deficiency prevails in epidemic proportions all over the Indian subcontinent with a prevalence of 70%–100% in the general population, as suggested by Ritu G and Ajay Gupta in 2014 [8]. In India, widely consumed foods such as dairy products are rarely fortified with vitamin D. Indian socioreligious and cultural practices do not facilitate adequate sun exposure, thereby negating potential benefits of plentiful sunshine. Consequently, subclinical vitamin D deficiency is highly prevalent in both urban and rural settings, and across all socioeconomic and geographic strata [8].
The socioeconomically backward people constitute a large percentage of the population in India.
Vitamin D status in India is inadequate not only in the lower but also in the upper socioeconomic classes.
Social, economic and cultural factors determine an individual’s access to resources, including material goods, healthcare, and educational opportunities. Population health and nutritional status is influenced by socioeconomic status and other social determinants, and these are used in risk predictive modelling of disease. In India, the Kuppuswamy scale and its modifications are used to classify the socioeconomic status of a family using a composite score of education and occupation of the head of the family along with monthly income of the family [8].
In 2014, Pettifor JM found that, low dietary calcium intake and poor vitamin D status are common
findings in children living in developing countries [14]. Despite many of the countries lying within the
tropics and subtropics, overcrowding, atmospheric pollution, a lack of vitamin D-fortified foods, and
social customs that limit skin exposure to sunlight are major factors in the development of vitamin D
deficiency. Low dietary calcium intakes are typically observed as a consequence of a diet limited in dairy
products and high in phytates and oxalates which reduce calcium bioavailability [15].
12 According to Kulie T, Vitamin D is a fat-soluble vitamin that plays an important role in bone metabolism and seems to have some anti-inflammatory and immune-modulating properties [16]. In addition, recent epidemiologic studies have observed relationships between low vitamin D levels and multiple disease states. Low vitamin D levels are associated with increased overall autoimmune diseases such as multiple sclerosis. Although it is well known that the combination of vitamin D and calcium is necessary to maintain bone density as people age, vitamin D may also be an independent risk factor for falls among the elderly [16].
In 2016, Akhtar S. suggested that, human body acquires a significant amount of vitamin D by cutaneous synthesis under the action of sunlight and less is supplied through nutritional sources [17].
Diversified sociocultural and economic determinants have been identified that limit the dietary intake of vitamin D and enough distribution of sunlight to maintain optimal levels of 25-hydroxyvitamin D (25(OH)D). Consequently, the world has witnessed a high prevalence of hypovitaminosis D in resource- limited South Asian countries. In this review, a South Asian perspective of vitamin D status is provided, critically examining India, Pakistan, Bangladesh, and Sri Lanka, and to shed light on potential determinants (latitude and season, sunshine exposure habits, age, gender, and genetic factors) leading to hypovitaminosis D among a variety of population groups [17].
Wide prevalence of vitamin D deficiency in healthy Indians has been studied mostly in lower and upper middle classes [18]. Individuals below poverty line were not represented well in these studies.
Hence, poor nutrition observed in these studies may also stem from lack of awareness of the features, benefits and necessity of balanced nutrition [18].
Vitamin D status and the prevalence of vitamin D deficiency and insufficiency have been addressed in many studies covering all continents. Vitamin D deficiency, when serum 25-hydroxyvitamin D is lower than 25 nmol/L, occurs in risk groups all over the world, mainly in the Middle East, China, Mongolia, and India. Risk groups for poor vitamin D status are children, especially those with low birth weight, adolescents, pregnant women, older persons, and non-Western immigrants [19]. Population surveys are revealing widespread deficiency and insufficiency in many countries around the world as various factors, some personal, cultural, or environmental, have caused a reduction in needed sun exposure [20].
Summarizing, vitamin D deficiency, generally defined as 25-hydroxyvitamin D (25(OH)D)
concentration <30 ng/ml, affects nearly half the world's population and are caused by a number of social,
environmental and individual risk factors.
13 1.2. Risk factors of vitamin D deficiency
Vitamin D is an extremely important vitamin that has powerful effects on several systems throughout the body. Unlike other vitamins, vitamin D functions like a hormone, and every single cell in the body has a receptor for it.
There are many reasons for high prevalence of vitamin D deficiency in India: [3].
•
Increased indoor lifestyle, thereby preventing adequate exposure to sunlight. This is mainly in the urban population due to modernization.
•
Changing food habits contribute to low dietary calcium and Vitamin D intake
•
Increased skin pigmentation and application of sunscreens
•
Unspaced and unplanned pregnancies in women with dietary deficit can lead to worsening of Vitamin D status in both mother and child.
•
Pollution can hamper the synthesis of Vitamin D in the skin by UV rays [21].
•
Phytates and phosphates which are present in fiber rich diet, can deplete Vitamin D stores and increase calcium requirement [11].
•
Cultural practices such as the burqa and purdah system [22].
1.2.1. The role of sun exposure.
Solar ultraviolet B (UVB) exposure is the primary source of vitamin D for most people. Many factors affect 25(OH)D concentrations related to solar UVB exposure, including skin pigmentation, solar zenith angle, atmospheric aerosols and clouds, time spent in the sun, amount of skin surface area exposed, use of sunscreen, age, and body mass index [23]. Cultural and lifestyle differences such as beauty standards, including high regard for fair skin in darker-skinned populations and avoidance of wrinkling; occupation;
religion; urban/rural residence; and fear of developing skin cancer or melanoma also affect some of those factors [23].
The Food and Agricultural Organization (FAO) and World Health Organization (WHO) Expert
Consultation states that the most physiologically relevant and efficient way of acquiring vitamin D in
most locations in the world around the equator (between latitudes 42
oN and 42
oS) is to synthesize it
endogenously from skin from 7-dehydro-cholesterol present in the subcutaneous fat by minimum of 30
minutes of skin exposure (without sunscreen) of the arms and face to mid-day sun [24]. It has been
concluded from the experimental data that exposure of the body in a bathing suit (almost 100% of body
surface area) to sunlight that causes slight pinkness of the skin [1 minimal erythemal dose (MED)] is
equivalent to ingesting approximately 20,000 IU of vitamin D orally. Therefore, exposure of 6% of the
14 body to 1 MED is equivalent to taking about 600 and 1,000 IU of vitamin D. Vitamin D synthesized in the skin lasts two times longer in the body compared to supplemental/ ingested dose [24].
A study conducted on sun exposure in elderly women in Jakarta, Indonesia (latitude of 6 °S) (14 repeated measurement of sun exposure intensity from 7 A.M. to 4 P.M. by using ultraviolet (UV) meter to calculate exposure in terms of MED/hour) the highest intensity of UVB was observed to have occurred at 11 A.M. to 1 P.M. ( ~2 MED/hour). But for convenience, they decided to ask subjects (n = 74 elderly women with type 4 skin) to expose to sunlight at 9 A.M. which contained by average about 0.6 MED/hour. After exposing to sunlight at this specific time and duration for 6 weeks, mean 25 OHD levels of participants increased from 59 nmol/L compared to the baseline to 84 nmol/L clearly proving the efficacy of sunlight in increasing the level of vitamin D [10, 71]. Similarly, a study from south India (Tirupati latitude 13.40 °N on and longitude 77.2
oE) using in vitro ampoule model with precursors of vitamin D (7- dehydrocholesterol) when exposed to sunlight converted to active vitamin D best between 11 A.M. to 2 P.M. clearly demonstrating the efficacy of sunlight in vitamin D synthesis [25]. The median percent conversion of 7-dehydrocholesterol to provitamin D3 and its photoproducts and percent of provitamin D3 and vitamin D3 formed was 11.5% and 10.2% respectively at a solar zenith angle of 36.8°
and at 12:30 P.M. [25].
Exposed to sunlight (playing outside) for more than 30 min a day exposing more than 40% of their body surface area have a normal vitamin D status (males: 91.6 nmol/L and females: 67.7 nmol/L) which was three times more compared with the toddlers who were indoors for most part of the day (males: 32 nmol/L and females: 21.1 nmol/L) [26]. Similarly, another study on toddlers in Delhi slums (latitude 28.35
oN and longitude 71.12
oE) demonstrated that those toddlers who were exposed to sunlight had better Vitamin D levels (~ 100 nmol/L) compared to those who were not ( ~20 nmol/ L) [27]. Interestingly authors of this study also identified (albeit retrospectively) that those families whose toddlers were exposed to sun were given educational material by the local healthcare workers explaining the benefits of sunshine. The 25OHD levels in South Indian subjects are relatively higher compared with the subjects from North India [14]. From the same data, a strong inverse correlation between the 25 OHD levels and latitude (r = -0.48; p < 0.0001) has been established clearly proving the effectiveness of equatorial closeness (smaller zenith angle) to natural Vitamin D synthesis [25].
Recent studies in south India using in vitro ampoule model with 7- dehydrocholesterol have shown
adequate formation of active form of vitamin D in mid-day sun. We as humans can get vitamin D from
abundant sunshine, by exposing 18% of body surface area (without sunscreen) to mid-day sun for 30-45
min to cause 1 minimal erythemal dose (MED) which is equivalent to taking about 600 to 1000 IU of
15 vitamin D. This is about the recommended daily dose by expert group on human nutrient requirements and the dose used in studies with fortified milk supplementation studies [24].
The concern for vitamin D estimation has increased tremendously in India despite the fact that it is located between 8.4° and 37.6° north latitude with the majority of its population living in regions experiencing ample sunlight throughout the year. According to the report of International Osteoporosis Foundation, in North India, 96% of neonates, 91% of healthy school girls, 78% of healthy hospital staff, and 84% of pregnant women were found to have hypovitaminosis D. On the other hand, prevalence of vitamin D deficiency in southern India was estimated to be 40% among males and 70% among females.
There was also a significant rural urban variation in the vitamin D deficiency status that was attributed to the diversity of occupation which the people were involved in [28].
It is important to note that the studies which have reported an increased prevalence of vitamin D deficiency in India have taken the cut-off limits of approximately 20 ng/ml for severe vitamin D deficiency, cut-off limits of 30 ng/ml for moderate vitamin D deficiency, and a cut-off limit of <35 ng/ml as mild deficiency. Though some of the researchers in India have tried to establish the cut-off limits for vitamin D deficiency, it is still largely based on the reference range provided by the company supplying the kit or the international standards. India is unique due to its large population diversity which definitely affects the vitamin D levels in the established population as described above. In the absence of such defined reference ranges established for the diverse Indian population, it is wrong to predict that Indian population is deficient of vitamin D. The blame on vitamin D deficiency is easy in the Indian subcontinent which is harder to prove and still harder to disprove. The initiative of Indian Council of Medical Research (ICMR) to study vitamins D levels in a large cohort of individuals representing the varied Indian population would definitely help in understanding the impact of vitamin D deficiency with regards to Indian population, and a task force has been formed to look into the concerns of vitamin D deficiency [29].
Historically, Indians obtained most of their vitamin D through adequate sun exposure; however, darker skin pigmentation and the changes which have accompanied India's modernization, including increased hours spent working indoors and pollution, limit sun exposure for many. Inadequate sun exposure results in reduced vitamin D synthesis and ultimately poor vitamin D status if not compensated by dietary intake [21].
The FAO/WHO expert Consultation states that in most locations of the world between 42°N and
42°S latitude there is abundant sunshine. Exposure to sunlight is responsible for physiological production
of Vitamin D endogenously in the skin from 7-dehydrocholesterol present in the subcutaneous fat. Thirty
16 minutes of exposure of the skin over the arms and face to sunlight, without application of sunscreen, preferably between 10 am to 2 pm (as maximum ultraviolet B rays are transmitted during this time) daily is required for adequate synthesis of vitamin D. Although vitamin D has been traditionally considered important for skeletal health, recent studies have reported that vitamin D also has beneficial effects on extra skeletal tissues. Several studies have suggested possible links between vitamin D and cardiovascular disease risk, diabetes, hypertension, and dyslipidemia. Vitamin D deficiency is prevalent in India, a finding that is unexpected in a tropical country with abundant sunshine. [30].
There is no national data describing the extent of vitamin D deficiency in India, studies conducted in various regions of the country across all age groups indicate poor vitamin D status. Historically, the main source of vitamin D for Indians has always been via synthesis in the skin resulting from exposure to UVB light from the sun. Lack of sun exposure due to lifestyle changes, darker skin color, high pollution levels, overcrowded residences with very little or no sunlight and almost no consumption of foods containing vitamin D are some of the risk factors for a poor vitamin D status in the healthy Indian population [31].
Vitamin D deficiency is a major health concern in India, notwithstanding the brightly shining sun.
The “adequacy of exposure to sunlight of an individual’s bare skin” required to photosynthesize vitamin D is grossly ill understood. Darker skin has high melanin content which acts as a natural sunscreen.
Therefore, darker skin produces a significantly lesser amount of vitamin D when compared with the individuals with fairer skin, such as Caucasians [32-34]. Thus, for Indian skin tone, minimum “direct sun exposure” required daily is more than 45 min to bare face, arms and legs to sun’s UV rays (wavelength 290–310 nm). With the exception of those who perforce need to work outdoors in the sun, most Indians do not get adequate sun exposure to produce sufficient amounts of vitamin D endogenously. Indian social and or religious norms related to public modesty dictate that most parts of an individual’s body, irrespective of gender, be covered. The not so D-lightful price of urbanization in big cities a majority of people live in very high population density areas. They perforce live in overcrowded tenements, which are closely packed and 3–4 stories high. Consequently, direct sunlight does not reach inside most parts of the dwellings, thereby disallowing any sun exposure to an individual in the privacy of one’s home.
Additionally, lack of space offers limited options for outdoor activities. Atmospheric pollution of
metropolitan India also factors in with respect to vitamin D status [35]. Use of sunscreen creams and
umbrellas do not help either. The extreme discomfort of the scorching heat associated with most sunny
days of Indian summer and (not to mention) the undying desire of most Indians to attain a fairer skin
complexion instantly extinguish any desire for sun exposure, and a person’s primary focus is on finding
ways to avoid the sun, at all costs. In the blazing heat of India these two concerns score very high and
17 the quest for vitamin D sufficiency takes a backseat, always. Therefore, in the Indian scenario, vitamin D sufficiency cannot be attained by depending on adequate sun exposure [14].
Serum 25(OH)D levels below 75 nmol/L are prevalent in every region studied whilst levels below 25 nmol/L are most common in regions such as South Asia and the Middle East. Older age, female sex, higher latitude, winter season, darker skin pigmentation, less sunlight exposure, dietary habits, and absence of vitamin D fortification are the main factors that are significantly associated with lower 25(OH)D levels [36].
1.2.2. Dietary risk factors of vitamin D deficiency.
A vitamin D status can be considered adequate in less than 50% of the world population at least in winter. Prevention requires moderate sunlight exposure, consumption of fish, fortification of foods, and the use of vitamin D supplements [37].
Dietary vitamin D intake is very low in India because of low consumption of vitamin D rich foods, absence of fortification and low use of supplements. All these factors contribute to poor vitamin D status as measured by low circulating levels of 25-hydroxy vitamin D. There is the need to fortify food staples with vitamin D or stimulate public health policies for vitamin D supplementation and dietary guidelines tailored to the Indian diet. Poor vitamin D status in India is accompanied by increased bone disorders including osteoporosis, osteomalacia in adults and rickets and other bone deformities in children [21].
The fact that vitamin D deficiency is widespread throughout the nation, irrespective of diverse dietary and social practices [14]. For instance, despite fish being a staple diet in Bengal (eastern India) vitamin D nutrition is no better than in other regions. Geographical stratification of data also indicates regions of the country from where more data is needed. The effectiveness or failure of vitamin D supplementation and food fortification in restoring vitamin D levels and bone health have been reviewed, while making the case that vitamin D deficiency needs to be recognized as a public health problem. This review also discusses the need and feasibility of fortification of staple foods with vitamin D in India.
Steps to be taken by the policymakers in India are also mentioned. Vitamin D
3is also found in animal food sources e.g., fatty fish (e.g., salmon, mackerel and tuna), cod liver oil, milk, etc. Vitamin D
2is found in vegetal sources like sun-exposed yeast and mushrooms. Notably, most dietary sources are not sufficiently rich in their vitamin D content [14].
Most of the food items rich in vitamin D are of animal origin. Most Indians are vegetarians.
Commonly, a dietary source of vitamin D for vegetarians is milk, provided milk has been fortified with
vitamin D. Milk is rarely fortified with vitamin D in India. The vitamin D content of unfortified milk is
18 very low (2 IU/100 mL). Additionally, milk and milk products are unaffordable to the socioeconomically underprivileged. Another concern in India is the rampant dilution and/or adulteration of milk and milk products.
Indian diet is low in calcium. Low dietary intake of calcium in conjunction with vitamin D insufficiency is associated with secondary hyperparathyroidism (SHPT). SHPT is further exacerbated by induced destruction of 25(OH)D and 1,25(OH)
2D by 24 hydroxylase [31]. 24 hydroxylase is the key enzyme of vitamin D catabolism and is regulated by 1,25(OH)
2D, PTH and FGF23 (Fibroblast Growth Factor 23) levels. FGF23 is a phosphate regulator. High serum phosphate levels increase production of FGF23 in bone osteocytes via the action of 1,25(OH)
2D. Subsequently, FGF23 reduces renal phosphate resorption, indirectly suppresses intestinal phosphate absorption and also suppresses PTH and 1,25(OH)
2D synthesis. Overproduction of FGF23 can result in increased morbidity associated with vitamin D deficiency [38]. This regulatory mechanism may explain the low 25(OH)D levels in rural subjects on a high phytate and/or low calcium diet, despite plentiful sun exposure. Most studies reported calcium intake much lower than the RDA (Recommended Daily Allowance) defined by the Indian Council of Medical Research (ICMR) [29].
Intake of caffeine from tea and coffee is very high in India [39]. Most Indians consume milk as part of their tea or coffee. The proportion of milk is very low in these drinks. Thus, calcium intake through these beverages is low. Vitamin D is stable during cooking. It is stable up to 200 °C. However, thermal stability of vitamin D is an inverse function of both temperature and time. In India, milk is boiled for several minutes before consumption. In India, most of the times, beverages like tea and coffee are boiled for several minutes to get the right flavor. This boiling may reduce the content of any vitamin D that there may have been left after boiling of the milk itself. Therefore, these beverages may not contribute significantly to either calcium or vitamin D intake in Indians. Vitamin D is a fairly robust vitamin. The preceding statements about its thermal degradation have been made as precautionary stance to not overstate the thermal robustness of this micronutrient. Additionally, studies have reported association of high caffeine intake with increased risk of low bone mineral density, osteoporosis, and osteoporotic fractures in middle-aged women. This situation is exacerbated in women with low calcium intake, especially in lean subjects [39,40].
High prevalence of lactose intolerance in India is a major deterrent pertaining milk consumption,
further lowering intake of calcium and vitamin D in these individuals. Ethnic and geographic variations
of lactose intolerance were observed, with a higher prevalence in southern (Dravidian descent) and
eastern India compared to northern India (Aryan descent) [41-44].
19 Notably, nearly all studies pertaining vitamin D status in healthy subjects reported a high phytate/calcium intake ratio. What Indians may require is a higher intake of calcium in their diet to lower the phytate/calcium intake ratio. Dietary habits in India have changed significantly. Many people remove a substantial proportion of bran from whole wheat flour before kneading to improve texture and fluffiness of chapatis (unleavened flat bread). Consumption of white bread is also very high. Most people prefer processed, split and polished pulses to whole seeds due to the ease of shorter time required for cooking and the consequent lowered expense of cooking fuel. Consumption of instant (or not) noodles and burgers also is on the rise across all socio-economic strata, with the exception of the impecunious [8].
High phytate in Indian diet especially among the socio-economically lower classes stems from the elementary and immediate need of sufficiency of the calorific need. Cereals and legumes are more affordable and easily available than vegetables, milk and other dairy products. Besides, they are sources of protein for the vegetarians. Many cereals are also sources of calcium, however due to chelation by phytates its bioavailability is limited.
Indians in general adhere to traditional cooking styles and practices, irrespective of their migration to any part of the world [8]. In tropical climate perishable food items putrefy quickly. Notably, in India there is no perceptible government regulation on the hygiene and microbial quality control of fresh produce that reaches from the producer to the end-consumer. Consumption of uncooked fresh produce, especially vegetables, milk, etc., is generally considered ill-advised. As in the rest of the world, in India too, slow cooking is widely practiced. This culinary practice is associated with decrease of amount of some vitamins because of the thermal instability. Protein malnutrition and poor overall nutrition resulting from poverty: Factually, balanced diet is only an occasional treat to the impecunious.
An old adage, “When a poor man eats chicken, one of them is sick”, says it all [8].
Indians are mostly vegetarians and Vitamin D rich foods are of animal origin. All the above- mentioned factors can be a cause in urban population. However, the rural population, who by the virtue of their occupation have sufficient sunlight exposure, too have low Vitamin D levels. This can be due to the high phytate and low calcium diet they consume. Phytate rich diet is known to reduce the intestinal absorption of calcium. Hence, low dietary calcium increases the catabolism of 25(OH) D and increases the inactive metabolites with the resultant reduction in 25(OH)D concentrations [11].
Even though the Indian diet is low in calcium content, it also has a lower protein content and
therefore low endogenous acid production, which may reduce urinary calcium loss. Therefore, the
amount of dietary calcium required to maintain calcium balance may be lower than for those in the
Occident. The protein-induced alterations in calcium homeostasis (and possibly in bone mass) have been
20 attributed to increments in endogenous acid production and net acid excretion due to the oxidation of the constituent Sulphur containing amino acids. On the other hand, the high salt content of Indian diet is likely to increase urinary calcium excretion. A direct relation between high sodium intake and lower bone mass has been reported [45].
1.2.3. Supplementation of vitamin D.
In India, as food fortification is lacking, supplementation with pharmaceutical preparations is the only means of treatment of vitamin D deficiency. Availability of various vitamin D supplements in the Indian market was studied, data about which was collected from annual drug compendium. The supplements were assessed for total number, different formulations, constituents and amount of each constituent present in the formulation. Vitamin D3 is available in the form of cholecalciferol, alfacalcidiol and calcitriol as single ingredient products and in combination with calcium and other micronutrients.
Most of the supplements contain calcitriol (46.5%) or alfacalcidiol (43%) as tablets (51.1%) and capsules (35.2%). Cholecalciferol, the preferred form for prophylaxis and treatment of vitamin D deficient states, constitutes only 10% of the available market preparations. High market sales of calcium supplements containing calcitriol indicate increasing intake of calcitriol rather than cholecalciferol; which could predispose to toxicity. There is a need for marketing and rational prescribing of the appropriate vitamin D supplement in ostensibly healthy Indian population. Implementation of population-based education and intervention programmes with enforcement of strict regulations could generate awareness and curb unsupervised intake of vitamin D containing dietary supplements. This health challenge mandates effective nutritional policies, fortification and supplementation programs and partnership between government, healthcare and industry to safeguard the health of Indian population at large [18].
Vitamin D supplementation varies with the RDA, tolerable upper levels in different age groups
and in certain circumstances [18]. The Institute of Medicine (IOM), USA guidelines suggest a vitamin D
sufficient level of 20 ng/ml to optimize bone health [46]. In contrast, US Endocrine Society recommends
that serum 25 (OH) D levels of 30 ng/ml (vitamin D sufficiency) should be attained for children and
adults to optimize the probability of good health and avoid other risk associated with vitamin D deficient
status. Furthermore, it is now acknowledged that previously recommended vitamin D intake of 200
IU/day in the US or 400 IU/day in the WHO report are grossly inadequate [47]. Thus, RDA of 600-800
IU is recommended to maintain adequate levels of vitamin D [47]. In our country, Indian Council of
Medical Research (ICMR) recommends a daily supplement of 400 IU/day of vitamin D for Indians under
situations of minimal exposure to sunlight [47]. However, in light of recent evidence, there is a need to
update these guidelines regarding vitamin D intake and supplementation in adults, vulnerable population
21 and susceptible groups [48-50]. It is now recognized that vitamin D is not as toxic as once thought to be.
IOM recommends that up to 4,000 IUs of vitamin D/day is safe for most children and adults. Studies in various populations have shown that adults can tolerate 10,000 IU of vitamin D/day for at least five months without altering their serum calcium or urinary calcium output [48]. However, in rare cases, vitamin D toxicity can cause hypercalcemia, hyperphosphatemia, nephron calcinosis, and soft tissue calcification, thus contributing to high risk of mortality [51].
The consequences of vitamin D deficiency are secondary hyperparathyroidism and bone loss, leading to osteoporosis and fractures, mineralization defects, which may lead to osteomalacia in the long term, and muscle weakness, causing falls and fractures. Vitamin D status is related to bone mineral density and bone turnover. Vitamin D supplementation may decrease bone turnover and increase bone mineral density. Several randomized placebo-controlled trials with vitamin D and calcium showed a significant decrease in fracture incidence. However, very high doses of vitamin D once per year may have adverse effects. When patients with osteoporosis are treated with a bisphosphonate, they should receive a vitamin D and supplement unless the patient is vitamin D replete [37].
Vitamin D synthesized in the skin lasts two-times longer in the body. In populations where there is limited exposure to sunlight, like dress-code limiting sun-exposure, usage of sunscreen with (SPF) greater than 8 etc., vitamin D supplementation may also be required. Since there is widespread calcium deficiency in Indian population, calcium supplementation should be an integral part of vitamin D supplementation therapy [11].
Supplementation resulted in significant improvement in vitamin D status, but a large proportion of the population had still did not attain sufficiency. The following study is noteworthy. In India, physicians often prescribe D
360,000 IU per week for 8 weeks for vitamin D deficiency. Twenty two healthy Indians with subnormal serum 25(OH)D levels were supplemented with oral D
360,000 IU/week and calcium 1 gm/day for 8 weeks. At 8 weeks the mean 25(OH)D levels increased from 10.16 (3.96) ng/mL to 22.4 (6.8) ng/mL and serum PTH normalized in all. Twenty two of the 23 subjects had 25(OH)D levels > 20 ng/ml. At the end of 12 months however, all the subjects were vitamin D deficient, once again. To sustain optimal 25(OH)D levels vitamin D supplementation would need to be ongoing after the initial loading [52].
In summary, literature review showed that vitamin D deficiency is highly prevalent in India with
some regional and social differences. Exposure to sunlight and nutritional practices are very important
factors associated with the prevalence of vitamin D deficiency. Some studies have shown that vitamin D
deficiency can be decreased by supplementing vitamin D. Our study is aimed at evaluation of associations
22
of sun exposure, nutrition habits and supplementation of vitamin D with vitamin D deficiency in patients
of three hospitals in Mumbai.
23
2. Material and methods
2.1. Study design and sample
A cross-sectional study was carried out in the outpatient departments of three hospitals in Mumbai (India) in September-October 2019. Patients visiting a doctor because of complaints about bone weakness, joint pain, and muscle pain were asked to participate in the study. The decision to investigate the patients with such symptoms was made because all of them had a blood vitamin D test. Those patients who agreed to participate signed informed consent form. They were asked to fill in the anonymous questionnaire and give it to a doctor. A doctor helped to fill in the questionnaires for some patients who were not able to understand English very well. To check serum 25-hydroxyvitamin D level, blood samples of respondents were collected. The level <30 ng/ml was considered as low.
In total, 200 individuals - 86 (43%) men and 114 (57%) women, participated in the study. The sample characteristics are presented in the Results section.
The study was approved by the Bioethics Centre of Lithuanian University of Health Sciences on 19-04-2019 (Appendix 1).
2.2. Research instrument and variables
The original questionnaire was designed for data collection (Appendix 2). It consisted of 27 questions which include:
• Sociodemographic characteristics
• Amount of sun exposure (suntan, use of sunscreen)
• Frequency of intake of different type of foods
• Usage of food supplements
• Self-assessed health
It was designed in that way, so the patients could choose an answer from several options.
The respondents were grouped in two age groups: 1) 20 to 39 years and 2) 40 and more years.
According to economic status, the respondents were divided into two groups: 1) upper middle class, 2)
middle class and below the poverty line. Nutrition habits were assessed using food frequency
questionnaire with possible answers: ‘Never’, ‘1-4 times a month’, ‘1-3 times a week’, ‘4-6 times a
week’, and ‘Daily’. According to glasses of milk consumption per week, the respondents were divided
into three groups: 1-2 glasses, 3 glasses, and ≥4 glasses. By fish consumption respondents were grouped
24 into two groups: 1) those consuming at least once a week and 2) those consuming less frequently or never.
Self-reported weight and height were used to calculate body mass index (BMI) as weight in kilograms divided by height in meters squared. Overweight was defined as BMI≥25 - <30kg/m
2and obesity as BMI≥30kg/m
2.
The serum 25-hydroxyvitamin D level was measured using the 25-OH vitamin D test. The level
<30 ng/ml was considered as low. According to blood vitamin D level, the participants were divided into two groups using the median of distribution: 25.5 ng/ml and less and 25.6 ng/ml and more.
2.3 Statistical analysis
Data analysis was performed using the statistical package IBM SPSS Statistic 20. The categorical
variables were presented as percentages and compared using the chi-square test and z test with Bonferroni
correction. The normality of distribution of continuous variables was tested by the Kolmogorov-Smirnov
test. Means and standard deviations (SD) were presented for the normally distributed continuous
variables. Student t test and one-way ANOVA test were used to compare the mean values of normally
distributed variables.
25
3. RESULTS
3.1. Sociodemographic characteristics, skin colour and clothing of the study population.
The study sample consists of 200 individuals. There was 86 (43%) men and 114 (57%) women.
The average age of men was 39.4±14.6 years and the average age of women was 42.2±14.4 years (p>0.05). The characteristics of the study population are presented in Table 3.1.1.
Table 3.1.1. Sociodemographic characteristics of the study population (%).
Characteristic Men
n=86
Women n=114
P value
Age groups
0.600
20-29 29.1 21.9
30-39 30.2 27.2
40-49 15.1 18.4
50-59 16.3 17.5
≥60
9.3 14.9
Education
0.002
Primary 3.5 5.3
Secondary 8.1 28.1*
Professional education 46.5 40.4
University 41.9 26.3*
Marital status
0.598 Married or living in partnership 58.1 58.8
Single 36.0 31.6
Divorced 3.5 3.5
Widow 2.3 6.1
Occupation
<0.001
Farming 4.7 1.8
Industrial work, construction 54.7 18.4*
Office work, services 12.8 29.8*
Housewife 0 17.5
Student 19.8 15.8
Unemployed 4.7 6.1
Others 3.5 10.5
Economic status
0.492
Upper middle class 17.4 17.5
Middle class 77.9 80.7
Below poverty line 4.7 1.8
*P<0.05 compared with men (z test with Bonferroni correction)
26 More men than women were highly educated. Almost half of the men (41.9%) and only a quarter (26.3%) of women had a university education. Secondary education was reported by 28.1% of women and 8.1% of men. More than half of the respondents were married or living in partnership. Every third of respondent was single. No difference by marital status was observed between men and women. A significantly higher proportion of men than women worked in industry or construction, 54.7% and 18.4%
respectively. More women than men worked in an office or were housewives. Evaluation of economic status showed that the majority of participants were from the middle class, 77.9% of men and 80.7% of women.
The highest proportion of respondents had white skin (Fig. 3.1.1). More women than men reported that their skin is white, 55.6% and 37.2% respectively. The higher proportion of men compared to women had white to light brown skin. Moderate and dark brown skin had 14% of respondents.
*P<0.05 compared with women (z test with Bonferroni correction) Fig. 3.1.1. Distribution of the participants by skin colour.
The majority of men (90.7%) reported wearing different clothes. Only 8 men (9.3%) answered that they wear dhoti kurta. More than half of women (59.6%) reported wearing all types of clothes (Fig.3.1.2). Every fourth woman (23.7%) reported wearing saree.
16,3
37,2*
32,6*
14 10,6
56,6
18,6
14,2
0 10 20 30 40 50 60
Light, pale white White, fair White to light brown Moderate,dark brown
%
Men Women
27 Fig. 3.1.2. Distribution of women by clothing (%).
In summary, most of the respondents were younger than 40 years old, married, having professional or university education, and being from the middle class. The majority of respondents had white or white to light brown skin and reported wearing all type of clothes. An only small part of men and women reported wearing dhoti kurta or saree.
3.2. Food habits, the use of supplements and sun exposure of the participants
Men consumed fresh vegetables more frequently than women. Daily consumption of fresh vegetables was reported by 39.5% of men and only 15.8% of women. Every fifth woman (22.8%) reported consumption of fresh vegetables 1-4 times a month. Women consumed fresh fruits more frequently than men on a daily basis (34.2%. and 23.3%, respectively); however, the difference was not statistically significant. Cooked vegetables were consumed daily more often by men than women. Daily consumption of bread was reported by one third of men and women.
Almost half of the women (45.6%) reported consumption of nuts, legumes and seeds 1-3 times a week. Daily consumption of nuts, legumes and seeds was reported by more men than women, 22.1% and 2.6% respectively. Men consumed seafoods and fish, which are good sources of vitamin D, more frequently than women. Fish was consumed at least 4 times a week by 41.7% of men and only by 22.9%
of women. Three times more men than women reported daily consumption of milk and dairy products, 21.2% and 7.0% respectively. Most women (45.6%) consumed milk and milk products only 1-3 times a week.
Almost half of the women reported they have never consumed meat, poultry and eggs. Those products were more popular among men. At least 4 times per week meat was consumed by 34.2% of
23,7
16,7 59,6
Saree Dress or skirt Different clothes
28 men and 14.5% of women, poultry - by 35.5% of men and 16.2% of women, and eggs – by 26.6% of men and 10.7% of women.
Table 3.2.1. Distribution (%) of the participants by the frequency of food consumption.
Food product Gender Never 1-4 times a month
1-3 times a week
4-6 times a
week Daily P
Fresh vegetables Men 4.7 11.6 25.6 18.6 39.5
0.001
Women 5.3 22.8* 21.1 35.1* 15.8*
Fresh fruits Men 1.2 8.1 33.7 33.7 23.3
0.336
Women 0.9 11.4 23.7 29.8 34.2
Cooked vegetables
Men 2.3 8.1 32.6 16.3 40.7
0.097
Women 1.8 12.3 36.0 26.3 23.7*
Breads Men 2.3 7.0 31.4 26.7 32.6
0.241
Women 1.8 12.3 19.3 35.1 31.6
Nuts, Legumes, Seeds
Men 1.2 16.3 34.9 25.6 22.1
0.000
Women 0.9 30.7* 45.6 20.2 2.6*
Seafood & fish Men 10.1 13.9 34.2 27.8 13.9
0.000
Women 42.0* 17.9 17.9* 16.1* 6.2
Milk & dairy products
Men 4.7 14.1 34.1 25.9 21.2
0.001
Women 0.9 28.9* 45.6 17.5* 7.0*
Meat Men 15.2 11.4 39.2 22.8 11.4
0.000
Women 49.1* 16.4 20.0* 13.6 0.9*
Poultry Men 13.9 21.5 29.1 19.0 16.5
0.000
Women 48.6* 9.0* 26.1 15.3 0.9*
Eggs Men 13.9 31.6 27.8 16.5 10.1
0.000
Women 48.2* 17.9* 23.2 8.9 1.8*
Fast food Men 20.9 40.7 23.3 9.3 5.8
0.001
Women 5.3* 51.8 27.2 15.8 0.0
Snacks Men 11.6 52.3 25.6 4.7 5.8
0.140
Women 7.9 38.6 34.2 11.4 7.9
Cakes & cookies Men 20.9 54.7 16.3 7.0 1.2
0.024
Women 6.1* 66.7 20.2 4.4 2.6
Sweets Men 39.5 38.4 17.4 3.5 1.2
0.000
Women 5.3* 36.0 40.4* 13.2* 5.3
Soft drinks with sugar
Men 39.5 41.9 14.0 1.2 3.5
0.000
Women 13.2* 33.2 39.5* 12.3* 1.8
*P<0.05 compared with men (z test with Bonferroni correction)
Fast food and snacks were more often consumed by women than men. Only 5.3% of women and 20.9% of men reported that they never consume fast food. The majority of the respondents consumed fast food and snacks 1-4 times per month. Cakes and cookies were also consumed mostly 1-4 times per month. Consumption of sweets and soft drinks with sugar was reported more often by women than men.
Only 4.7% of men and 18.5% of women consumed sweets at least 4 times a day. Even 39.5% of women
and only 14% of men reported that they drink soft drinks 1-3 times a week.
29 On average, men consumed 2.6±1.3 glasses of milk per week and women - 2.8±1.2 glasses per week (p>0.05). According to the glasses of milk consumed we divided the participants into three groups (Fig.3.2.1). Very low proportion of men (7.0%) and women (14.0%) reported consumption of 4 and more glasses of milk per week. Approximately 47% of participants consumed 3 glasses of milk per week. One or two glasses of milk per week were consumed by 45.3% of men and 39.5% of women.
P>0.05
Fig.3.2.1 Distribution of respondents according to the number of glasses of milk consumed per week.
Distribution of respondents according to the type of diet that they are consuming is presented in Figure 3.2.2. The most popular was the mixt type of diet. Most men (79.1%) than women (54.4%) answered that they use mixt diet. More women than men reported that their diet is lactovegetarian (27.2% and 11.6% respectively) or lactovegetarian plus fish and eggs (17.5% and 7.0%
respectively). Only a few people answered that they are on a vegan diet.
45.3
47.7
7.0 39.5
46.5
14.0
0,00%
10,00%
20,00%
30,00%
40,00%
50,00%
60,00%
1-2 glasses 3 glasses 4 and more glasses
Percentage
Number of glasses per week
Male Female
30
*P<0.05 compared with men (z test with Bonferroni correction) Fig. 3.2.2 Distribution of the respondents according to type of diet
The difference in distribution by types of diets was found between two age groups in men.
(Fig. 3.2.3). More young (20-39 years old) respondents than older (40 and more years old) respondents reported that they use a mixed diet (90.2% and 62.9% respectively). Older respondents preferred lactovegetarian or lactovegetarian plus fish and eggs diet.
*P<0.05 compared with age group 20-39 years (z test with Bonferroni correction) Fig. 3.2.3 Distribution of men according to type of diet and age
The same tendencies; however, without statistical significance, were found in women (Fig.
3.2.4). More younger women used a mixed diet and more older women preferred a lactovegetarian diet.
79.1
7.0 11.6
2.3 54.4*
17.5*
27.2*
0.9 0,00%
10,00%
20,00%
30,00%
40,00%
50,00%
60,00%
70,00%
80,00%
90,00%
Mixed diet Lacto vegetarian diet + fish
& eggs
Lacto vegetarian diet Vegen diet
percentage
Type of diet
Male Female
90,2
2 7,8
0 62,9*
14,3* 17,1
5,7 0
20 40 60 80 100
Mixed diet Lacto vegetarian diet + fish &
eggs
Lacto vegetarian diet Vegan diet
%
type of food
20-39 years More than 40 years
31 P>0.05
Fig. 3.2.4 Distribution of women according to type of diet and age
More women than men used multivitamins daily, 47.8% and 36.0% respectively (p<0.05) (Fig.3.2.5 and 3.2.6). Daily intake of multivitamins was associated with age of men and women. More older than younger men reported the intake of multivitamins (60.0% and 19.6%, respectively) (Fig.3.2.5).
The same difference between age groups was observed in women (Fig.3.2.6). The intake of multivitamins was reported by 59.6% of older women and by 35.7% of younger women.
*P<0.05 compared with age group 20-39 years
Fig. 3.2.5 Distribution of men according to daily intake of multivitamins and age
58,9
19,6 21,4
0 50
15,5
32,8
1,7 0
10 20 30 40 50 60 70
Mixed diet Lacto vegetarian diet + fish
& eggs
Lacto vegetarian diet Vegan diet
%
Type of food
20-39 years More than 40 years
19,6
60*
36 80,4
40*
64
0 10 20 30 40 50 60 70 80 90
20-39 years More than 40 years Total
%
Age of respondents
Yes No
32
*P<0.05 compared with age group 20-39 years
Fig. 3.2.6 Distribution of women according to daily intake of multivitamins and age
Almost half of respondents used three multivitamin tablets of per day (Fig. 3.2.7). One third reported the intake of 2 tablets per day
P>0.05
Fig. 3.2.7 Distribution of respondents according to number of multivitamin tablets used per day
Vitamin D plus calcium supplements were used by a half of respondents (Fig 3.2.8). More women than men reported the intake of supplements, 56.1% and 37.2 respectively.
35,7
59,6*
47,8 64,3
40,4*
52,2
0 10 20 30 40 50 60 70
20-39 years More than 40 years Total
%
Age of respondents
Yes No
8,3
30,6
58,3
6,1 2,8
30,3
54,5
9,1
0 10 20 30 40 50 60 70
1 tablet 2 tablet 3 tablet 4 tablet
%
no. of tablets
Men Women
33
*P<0.05 compared with men
Fig. 3.2.8 Distribution of respondents according to daily intake of vitamin D supplements.
Older men used vitamin D plus calcium supplements more often than younger ones, 65.7% and 17.6% respectively (Fig. 3.2.9).
*P<0.05 compared with age group 20-39 years
Fig. 3.2.9 Distribution of men according to daily intake of vitamin D supplements and age.
The same association was found in women: 67.2% of older women and 44.6% of younger women reported the intake of vitamin D plus calcium supplements (Fig. 3.2.10).
37,2
56,1*
48 62,8
43,9*
52
0 10 20 30 40 50 60 70
Men Women Total
%
Gender
Yes No
17,6
65,7*
32,7 82,4
34,3*
62,8
0 10 20 30 40 50 60 70 80 90
20-39 years More than 40 years Total
%
Age
Yes No
34
*P<0.05 compared with age group 20-39 years
Fig. 3.2.10 Distribution of women according to daily intake of vitamin D supplements and age The highest proportion of men (40.6%) and women (48.4%) used 600-700 IU vitamin D supplements daily (Fig.3.2.11). More than one third of respondents used 750-900 IU of supplements. The intake of more than 950 IU of supplements was reported by the lowest proportion of respondents (21.9%
of men and 15.6% of women).
P>0.05
Fig. 3.2.11 Distribution of respondents according to daily intake of IU of vitamin D supplements
44,6
67,2*
55,4 56,1
32,8*
43,9
0 10 20 30 40 50 60 70 80
20-39 years More than 40 years Total
%
Age
Yes No
40,6 37,5
21,9 48,4
35,9
15,6
0 10 20 30 40 50 60
600-700 IU 750-900 IU > 950 IU
%
Vitamin D supplements IU
Men Women
35 More women than men reported taking cod liver oil or omega 3 fatty acids, 38.6% and 22.1%, respectively (Fig.3.2.12).
*P<0.05 compared with men
Fig. 3.2.12 Distribution of respondents according to intake of cod liver oil or omega 3 fatty acids by gender
Almost quarter of men reported received suntan in the past 12 months (Fig. 3.2.13). Higher proportion of older than younger men received suntan, 37.1% and 15.7% respectively.
*P<0.05 compared with age group 20-39 years
Fig. 3.2.13 Distribution of men according to suntan in the past 12 months by age
22,1
38,6*
31,5 77,9
61,4*
68,5
0 10 20 30 40 50 60 70 80 90
Men Women Total
%
Gender
Yes No
15,7
37,1*
24,4 84,3
62,9*
75,6
0 10 20 30 40 50 60 70 80 90
20-39 years More than 40 years Total
%
Age group
Yes No
36 No association between received suntan in the past 12 months and age was observed in women (Fig. 3.2.14).
P>0.05
Fig. 3.2.14 Distribution of women according to suntan in the past 12 months by age More women (56.1%) than men (34.9%) reported using sunscreen (Fig.3.2.15).
*P<0.05 compared with men
Fig. 3.2.15 Distribution of respondents according to use of sunscreen
28,6 31 29,8
71,4 69 70,2
0 10 20 30 40 50 60 70 80
20-39 years More than 40 years Total
%
Age
Yes No
34,9
56,1*
47 65,1
43,9*
53
0 10 20 30 40 50 60 70
Men Women Total
%
Gender
Yes No
