Maternal 25‐hydroxyvitamin D level and the occurrence of neural tube defects in Tunisia

OBJECTIVE: To determine whether low vitamin D levels in pregnant women are associated with the occurrence of neural tube defects (NTDs) in Tunisia. METHODS: In a prospective study, pregnant women were recruited at a center in Tunis between January 1, 2012, and December 30, 2013. Women carrying a fetus with a severe NTD were recruited before elective termination. Matched, healthy pregnancy women were enrolled into a control group. Plasma levels of 25-hydroxyvitamin D were measured by a competitive chemiluminescence immunoassay. RESULTS: Overall, 68 women formed the NTD group and 64 the control group. The mean maternal vitamin D level was significantly lower in the NTD group (20.65±10.25nmol/L) than in the control group (28.30±13.82nmol/L; P<0.001). Vitamin D deficiency was recorded for 53 (78%) women in the NTD group and 39 (61%) in the control group. Vitamin D insufficiency was recorded for 15 (22%) women in the NTD group and 20 (31%) in the control group. Vitamin D sufficiency was found only in the control group (n=5 [8%]; P<0.001). CONCLUSION: The findings confirm an association between a decreased vitamin D level in pregnant women and the risk of fetal NTDs.