Abstract: Vitamin D has an important role in early life; however, the optimal vitamin D status
during pregnancy is currently unclear. There have been recent calls for pregnant women to
maintain circulating 25-hydroxyvitamin D (25(OH)D) concentrations >100 nmol/L for health, yet
little is known about the long-term potential benefits or safety of achieving such high maternal
25(OH)D concentrations for infant or child health outcomes. We examined maternal vitamin
D status and its associations with infant anthropometric and later childhood neurocognitive
outcomes in a mother-child cohort in a sun-rich country near the equator (4.6◦ S). This study was
conducted in pregnant mothers originally recruited to the Seychelles Child Development Nutrition
Study. Blood samples (n = 202) taken at delivery were analysed for serum 25-hydroxyvitamin
D (25(OH)D) concentrations. Multiple linear regression models assessed associations between
maternal 25(OH)D and birth weight, infant head circumference, and neurocognitive outcomes in
the children at age 5 years. Mothers were, on average, 27 years of age, and the children’s average
gestational age was 39 weeks. None of the women reported any intake of vitamin D supplements.
Maternal 25(OH)D concentrations had a mean of 101 (range 34–218 nmol/L) and none were deficient
(<30 nmol/L). Maternal 25(OH)D concentrations were not associated with child anthropometric or
neurodevelopmental outcomes. These findings appear to indicate that a higher vitamin D status is
not a limiting factor for neonatal growth or neurocognitive development in the first 5 years of life.
Larger studies with greater variability in vitamin D status are needed to further explore optimal
cut-offs or non-linear associations (including for maternal health) that might exist among populations
with sub-optimal exposure.
- vitamin D