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 ± 10.25 nmol/L) than in the control group (28.30 ± 13.82 nmol/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.