Association between maternal vitamin D status during pregnancy and offspring cognitive function during childhood and adolescence.

Background And Objectives: Animal studies have demonstrated poor cognitive outcomes in offspring in relation to maternal vitamin D deficiency before and/or during pregnancy. Human studies linking maternal vitamin D status during pregnancy with offspring cognitive function are limited. We aimed to test the hypothesis that lower maternal vitamin D status during pregnancy is associated with poor offspring cognitive ability in an Indian population.

Methods And Study Design: Cognitive function was assessed in children from the Mysore Parthenon birth cohort during childhood (age 9-10 years; n=468) and adolescence (age 13-14 years; n=472) using 3 core tests from the Kaufman Assessment Battery for children and additional tests measuring learning, long-term retrieval/ storage, short-term memory, reasoning, verbal fluency, visuo-spatial ability, and attention and concentration. Maternal serum 25-hydroxyvitamin D concentration was measured at 30±2 weeks of gestation.

Results: During pregnancy 320 (68%) women had 'vitamin D deficiency' (serum 25-hydroxyvitamin D concentration <50 nmol/L). Girls scored better than boys in tests of short-term memory, reasoning, verbal fluency, and attention (p<0.05 for all). Maternal vitamin D status (low as well as across the entire range) was unrelated to offspring cognitive function at both ages, either unadjusted or after adjustment for the child's current age, sex, maternal age, parity, season at the time of blood sampling, gestational age, the child's birth and current size, socio-economic status, parents' education, maternal intelligence and home environment.

Conclusions: In this population, despite a high prevalence of vitamin D deficiency during pregnancy, there was no evidence of an association between maternal vitamin D status and offspring cognitive function.