High prevalence of vitamin D deficiency in newborn infants of high-risk mothers.

OBJECTIVE: To determine the prevalence of vitamin D deficiency in newborn infants of mothers at risk of vitamin D deficiency because of dark skin or the wearing of concealing clothes (such as a veil) compared with a group presumed not to be at risk. A second aim was to correlate these newborn infants' vitamin D concentrations with biochemical parameters of vitamin D metabolism and bone turnover at birth. DESIGN: A prospective study conducted between April 2004 and February 2006 including women delivering during this period and their newborn infants. SETTING: The outpatient clinic of the obstetrics department, Sint Franciscus Gasthuis, Rotterdam, the Netherlands. PATIENTS: Eighty seven newborn infants of healthy mothers with either dark skin and/or concealing clothing (risk group) or light skin (control group). RESULTS: We found a significant difference in the prevalence of vitamin D deficiency (25-hydroxyvitamin D(3) <25 nmol/l) between newborn infants of mothers at risk and those of mothers in the control group (63.3% vs 15.8%; p<0.001). Mean alkaline phosphatase concentrations were significantly higher in the at risk group. CONCLUSIONS: Newborn infants of mothers with dark skin or wearing concealing clothes are at great risk of vitamin D deficiency at birth. The clinical implications are unknown. Further research is necessary to determine the long-term consequences of maternal and neonatal vitamin D deficiency so that guidelines on vitamin D supplementation during pregnancy can be issued.