Sunlight is an important factor in the production of vitamin D in the skin. For babies born during winter months, however, their lack of sun exposure may reduce the levels of this vitamin in the body, leading to hampered bone growth.

In a study published in the journal The Lancet Diabetes & Endocrinology, vitamin D supplements were found to benefit babies born during winter months, potentially counteracting reduced levels of vitamin D because of the lack of sunlight.

Other studies have linked vitamin D levels during pregnancy with increased bone mass in developing babies. The bone growth of babies in the womb is associated with overall bone health in later life, and those babies born with weaker bones are at a higher risk of developing conditions such as osteoporosis when they grow older.

First Study To Measure Effect Of Maternal Vitamin D Intake

This study, dubbed the Maternal Vitamin D Osteoporosis Study (MAVIDOS), is the first of its kind to measure the effect of vitamin D supplementation during pregnancy on the bone health of infants through bone density scans.

The researchers recruited more than 1,100 women from three UK study locations: Oxford, Southampton and Sheffield. The participants were between 14 and 17 weeks pregnant and had readings of low to normal vitamin D levels.

The study involved dividing the women into two groups. Half of them took a 1,000 IU vitamin D capsule each day while the others were given a placebo capsule daily until the delivery of the baby.

What They Found

The researchers found that vitamin D supplements had no major effect on the infant's bone mass. In fact, there was no significant difference in bone mass between babies born to mothers who took vitamin D capsules and those who took placebo capsules.

Babies born during winter to mothers who took in daily vitamin D supplements, however, had improved bone mass than winter babies born to mothers who had taken placebo capsules.

The researchers also discovered that among mothers who gave birth during winter, vitamin D levels decreased between 14 and 34 weeks of pregnancy in the group who took placebo capsules, but not in mothers in the vitamin D supplementation group.

"Our unit seeks to develop interventions to improve bone health early in life. We found that vitamin is safe and effective in raising vitamin D levels in mothers whose babies are born during winter months," said Professor Cyrus Cooper, Director of the MRC Lifecourse Epidemiology Unit, University of Southampton.

Supplements Ensure Pregnant Women Are Vitamin D Replete

Taking in vitamin D supplements during pregnancy did not show increased bone mineral content (BMC) among infants but demonstrated that supplementation made sure most pregnant women were vitamin D replete. This means that the vitamin D levels of pregnant women remained sufficient for both the mother and developing baby.

Supplementation will ensure adequate vitamin D levels in pregnant women to provide for the baby's developing bones and overall bone health.

Photo: Eugene Oden | Flickr 

ⓒ 2021 All rights reserved. Do not reproduce without permission.