A study carried out by Northwestern Medicine has found that women who are obese throughout their pregnancies may risk providing insufficient vitamin D levels to their babies.

The study, which was published Jan. 4 in the Journal of Clinical Endocrinology and Metabolism, was carried out as part of a larger project looking at the degree to which a person’s level of body fat at birth predicts body fat levels later in life. Researchers focused on vitamin D levels in mother and child because the molecule is associated with a number of health issues, including obesity, according to a University news release.

The study found that obese and lean mothers had about the same levels of vitamin D in their own blood streams, but those who were obese passed less vitamin D along to their children.

“Nearly all of mothers in this study reported taking prenatal vitamins, which may be the reason why their own vitamin D levels were sufficient, but the babies born to the obese mothers had reduced levels of vitamin D,” said Dr. Jami L. Josefson, first author of the study and a pediatrics professor at Feinberg, in the release. “It’s possible that vitamin D may get sequestered in excess fat and not transferred sufficiently from an obese pregnant woman to her baby.”

According to the release, the study included 61 women who all had normal or obese body mass indexes and gave birth at Prentice Women’s Hospital of Northwestern Memorial Hospital in Chicago. The mothers’ vitamin D levels were collected between 36 and 38 weeks of gestation, and those of the babies were collected from umbilical cord blood taken just after birth.

— Jillian Sandler