Prenatal vitamin use and vitamin D status during pregnancy, differences by race and overweight status

Objective:we aimed to study whether prenatal vitamin (pnv) use protects against low 25-hydroxyvitamin d (25[oh]d) levels in all women and particularly in obese and black women who are both at risk of vitamin d deficiency and poor pregnancy outcomes.study design:we studied 1019 women enrolled in a prospective study at brigham and women’s hospital in boston, from 2007 to 2009. we used multivariable logistic regression to analyze associations of pnv use and odds of vitamin d deficiency defined as 25[oh]d levels <50 nmol l−1.result:in all, 56% of black and 86% of white women reported pre- and/or postconceptional pnv use. in the first trimester, 75% of black and 19% of white women were vitamin d deficient. lack of pnv use among black women was not associated with vitamin d deficiency (adjusted odds ratio (or) 1.0, 95% confidence interval (ci) 0.4, 2.3) but was among white women (or 3.5, 95% ci 2.1, 5.8) (interaction p<0.01).conclusions:ongoing trials of vitamin d supplementation during pregnancy should consider potential effect modification by race/ethnicity.