Correction of vitamin D deficiency in a cohort of newborn infants using daily 200 IU vitamin D supplementation.

INTRODUCTION: Although the role of vitamin D in the prevention of rickets has long been well established, controversies still exist on the ideal dose of vitamin D supplementation in infants. OBJECTIVE: We assessed serum 25-hydroxyvitamin D (25OHD) status simultaneously in maternal and cord samples and the response to vitamin D3 supplementation in neonates. METHODS: Serum 25OHD levels were evaluated from maternal, and umbilical cord samples from term normal pregnancies. Repeat 25OHD levels were assessed in neonates with 25OHD below 30 nmol/L following vitamin D3 200 IU daily after 6 weeks. RESULTS: Blood samples were taken including 57 cord samples and 16 follow-up neonatal samples. Maternal and cord serum 25OHD were 43 ± 21 and 29 ± 15 nmol/L, respectively. Infants with 25OHD < 30 nmol/L (19.8 ± 4.7 nmol/L) had a significant increase in serum 25OHD (63.3 ± 14.5 nmol/L) following vitamin D3 200 IU daily after 6 weeks. CONCLUSION: Healthy Irish infants born at term are at high risk of vitamin D deficiency, but vitamin D3 200 IU daily, rapidly corrects poor vitamin D status.

Relationship between vitamin D knowledge and 25-hydroxyvitamin D levels amongst pregnant women.

BACKGROUND: Pregnant women living at northerly latitudes are at risk of suboptimal vitamin D status. There is a paucity of studies correlating knowledge, attitudes and practices of vitamin D with serum levels amongst pregnant women. We aimed to determine the prevalence of suboptimal vitamin D status in pregnant women of various ethnicities attending two Dublin maternity hospitals and to assess levels of knowledge, attitudes and practices concerning vitamin D. METHODS: We conducted a cross-sectional study of 116 pregnant women of Irish, Asian, Sub-Saharan African and Middle Eastern and North African (MENA) origin. Vitamin D status was determined by measurement of serum 25-hydroxyvitamin D (25OHD). We examined knowledge, attitudes and practices concerning vitamin D using an interview-assisted questionnaire. RESULTS: The median (interquartile range) 25OHD level was 25.9 (16.5-44.7) nmol L(-1). Using a cut-off point of <30 nmol L(-1) , the proportion at risk of deficiency was significantly higher among MENA (88%; P < 0.001) and Sub-Saharan African women (68%; P = 0.019) than Irish women (36%). Eighty-two women (71%) reported they had insufficient knowledge about vitamin D and its sources. Vitamin D containing supplement usage was the strongest predictor of 25OHD levels ≥30 nmol L(-1) (odds ratio = 18.03, 95% confidence interval = 5.7256.8, P < 0.001). CONCLUSIONS: Suboptimal vitamin D status is common in this cohort of pregnant women, especially among those of Sub-Saharan African and MENA origin. Awareness of vitamin D dietary sources is poor among all subgroups. Recommending vitamin D containing supplements may be the best strategy at present for improving vitamin D status with a need for increased vitamin D education.