Two studies published in March show the potential effects of vitamin D deficiency during pregnancy. The first, published in PLOS ONE, shows a potential association between overweight and obesity during pregnancy and low vitamin D levels.  Caucasian mothers residing at latitude 41-43 degrees and between 39-41 week gestation period had their maternal and cord blood sera measured for serum vitamin D. Results showed that low serum levels of vitamin D in both maternal and cord blood were found in mothers with a higher BMI.

Previous studies have found that low vitamin D in pregnant mothers can lead to heavier infants and an elevated risk of childhood obesity and type 2 diabetes. While this particular study found no significant association with low vitamin D and heavy infants, it warrants further study. The results were also not definitive enough to create a recommendation for vitamin D supplementation for pregnant women.

The second study published in JAMA Neurology found a potential link between deficient vitamin D levels in pregnant women and an elevated risk of multiple sclerosis (MS) in adulthood for their offspring. The study identified 193 individuals diagnosed with MS whose mothers were in the Finnish Maternity Cohort and had available serum samples of the affected person. Of these, 176 were matched to 326 controls on region of birth, date of collection of maternal serum sample, birth date of the mother and birth date of the child.

“Maternal vitamin D deficiency during early pregnancy was associated with a nearly 2-fold increased risk of MS in the offspring compared with women who did not have deficient 25(OH)D [vitamin D] levels,” say the study’s authors. That is a 90% elevated risk of MS.

While the study does not determine a dose-response effect for increasing vitamin D intake, Andrea Wong, Ph.D., vice president, scientific and regulatory affairs, Council of Responsible Nutrition says, “As a woman, I believe that if there’s any chance that a woman could reduce the risk of her unborn child’s developing MS later in life, that’s something a mother-to-be would strongly consider—especially if it’s doing something as simple as adding a vitamin D supplement daily.”

While more research is needed for more definitive answers, these studies add to the growing body of scientific research demonstrating the importance of vitamin D.

Published in WholeFoods Magazine Online 3/15/2015