VITAMIN D STATUS AT BIRTH IN BRUSSELS- PRELIMINARY RESULTS

VITAMIN D STATUS AT BIRTH IN BRUSSELS-

PRELIMINARY RESULTS

F. Petry, L. Gianquinto, H. Cheblal

, N. Hennebert

, J. Vanderpas

, J. L.

Wayenberg,

Departments of Paediatrics and Clinical Chemistry

; Hopital Français-César de Paepe ; Department of Clinical Chemistry, Institut Bordet

, Université Libre de Bruxelles, Brussels

Introduction : The 25(OH) vitamin D (25OHD) concentration measured in cord blood reflects the vitamin D status at birth and is correlated to the bone mineral content. The aims of the study were to evaluate the rate of neonatal vitamin D deficiency and to identify its risks factors in our city.

Methods : All infants born in our institution from April 2003 to March 2004 were prospectively included in the study. Cord serum 25OHD was measured using a competitive chemoluminescent immunoassay method (LIAISON- DIASORIN). We calculated the prevalence of moderate and severe vitamin D deficiency, defined as a cord serum 25OHD concentration ranging from 5 to 9.9 ng/mL and less than 5 ng/mL, respectively. Using contingency tables, we attempt to relate the rate of neonatal vitamin D deficiency to the following variables: maternal variables (ethnic origin, age, parity, interbirth interval), pregnancy variables (number of foetus, evolution, term, clothing and sun exposure habits, alimentary vitamin D intake, vitamin supplementation) and neonatal variables (gender, weight, height, birth weight percentile).

Results : Out of the 753 infants born during the study period, 716 were enrolled in the study. Serum cord 25OHD was less than 5 ng/mL in 119 (16.6%) and ranged from 5 to 9.9 ng/mL in another 207 (28.9%). The rate of vitamin D deficiency was significantly higher in infants born in winter and spring than in those born in summer and autumn (p<0.05) and in infants from mother originating from Maghreb and Near-East than in those originating from Europe and Africa (p<0.05). Vitamin D deficiency was also associated to covered clothing habits (p<0.05), to absence of any sunbathing (p<0.05) and to low (<

400 UI/day) vitamin D supplementation (p<0.001) of the mother during the pregnancy.

The prevalence of neonatal vitamin D deficiency was not related to maternal age, parity, number of foetus, interbirth interval, any pregnancy complication, term, birthweight and alimentary vitamin D intake during pregnancy.

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VITAMIN D STATUS AT BIRTH 227 Conclusion : Neonatal vitamin D deficiency is common in our institution. Skin exposure to sun (clothing habits, amount of sunbathing and season of birth) and low vitamin D supplementation seems to be its major determinants.

Key words : Vitamin D deficiency, newborn.