A recent study found that pregnant mothers who had sufficient vitamin D levels at 26 weeks or less gave birth to babies with increased weights and head circumference.
The study, accepted for publication in the Journal of Clinical Endocrinology & Metabolism, examined 2146 pregnant women with vitamin D levels measured at 26 weeks of gestation or less. Birth weight, head circumference, and placental weight were measured within 24 hours of birth.
The researchers found that mothers with 25(OH)D levels ≥15 ng/ml gave birth to newborns who weighed a mean 46 grams heavier and with head circumferences 0.13 cm larger compared with infants born from mothers who had a vitamin D status < 15 ng/ml.
“Birth weight and head circumference rose with increasing 25(OH)D up to 15 ng/ml and then leveled off,” the authors explain.
Previous studies have shown inconsistent associations between maternal vitamin D status and fetal size.
The authors conclude,
“Maternal vitamin D status is independently associated with markers of physiological and pathological growth in term infants. Adequately powered randomized controlled trials are needed to test whether maternal vitamin D supplementation may improve fetal growth.”
Gernand AD, et al. Maternal serum 25-Hydroxyvitamin D and measures of newborn and placental weight in a US multicenter cohort study. The Journal of Clinical Endocrinology & Metabolism. November, 2012.