Vitamin D in Pregnancy Makes for Stronger Children, Study Finds

Higher levels of vitamin D during late pregnancy may improve muscle strength in children, according to an observational study published in the January issue of The Journal of Clinical Endocrinology & Metabolism.

While low vitamin D levels have been linked to reduced muscle strength in adults and children, the researchers said little is known about how vitamin D exposure in utero affects children.

University of Southampton, UK, researchers analyzed 678 mother-child pairs from the Southampton Women’s Survey by assessing the handgrip strength, lean mass, and percent lean mass of the children at age 4 years.

They found that higher maternal vitamin D concentration in pregnancy was associated with better handgrip strength in her child (β = 0.10 SD/SD, P = 0.013), and the finding remained after adjusting for factors such as duration of breastfeeding and the child’s physical activity level (β = 0.13 SD/SD, P = 0.014).

The results showed that the higher the levels of vitamin D in the mother, the higher the grip strength of the child.

There was a less pronounced association between the mother’s vitamin D levels in pregnancy and her child’s muscle mass. While higher vitamin D was associated with better percent lean mass (β = 0.11 SD/SD, P = 0.006), there was not a statistically significant association with total lean mass (β = 0.06 SD/SD, P = 0.15). In addition, the muscle mass association did not persist after adjustment for confounding factors (β = 0.09 SD/SD, P = 0.11).

"These associations between maternal vitamin D and offspring muscle strength may well have consequences for later health; muscle strength peaks in young adulthood before declining in older age and low grip strength in adulthood has been associated with poor health outcomes including diabetes, falls and fractures,” said Dr. Nicholas Harvey, the lead author, in a statement. “It is likely that the greater muscle strength observed at four years of age in children born to mothers with higher vitamin D levels will track into adulthood, and so potentially help to reduce the burden of illness associated with loss of muscle mass in old age."

Pertinent Points:
- Higher levels of vitamin D in expectant mothers during late pregnancy was associated with improved muscle strength in children at age 4.
- The association between the mother’s vitamin D levels in pregnancy and her child’s muscle mass was less pronounced and not statistically significant when adjusted for confounding factors.

References:

Reference

Harvey NC, Moon RJ, Sayer AA, et al, for The Southamptom Women’s Survey Study Group. Maternal antenatal vitamin D status and offspring muscle development: findings from the Southamptom Women’s Survey.

J Clin Endocrinol Metab.

2014;99:330-337.