Maternal Levels of Vitamin D During Gestation May Dictate Multiple Sclerosis in Offspring

During pregnancy, a mother’s vitamin D deficiency may increase her child’s risk for multiple sclerosis (MS), according to findings published in JAMA Neurology. Previous research has indicated that elevated levels of vitamin D is linked to decreased risk for MS in adulthood, but it has also shown that vitamin D exposure in utero may be a risk factor for MS later in life.

Researchers from the Harvard T. H. Chan School of Public Health studied almost 200 MS patients in order to examine whether vitamin D levels in early pregnancy were associated with a child’s risk of MS. These patients mothers’ were part of the Finnish Maternity Cohort (FMC) and the researchers matched them to more than 300 control participants for comparison measurements of region of birth in Finland, date of maternal serum sample collection, date of mother’s birth and date of child’s birth.

Most of the blood samples were collected during the first trimester and showed average maternal vitamin D levels were categorized as “insufficient.” For children born to mothers with insufficient vitamin D levels, their risk for MS was 90 percent higher than children born to mothers who were not vitamin D deficient.

“While our results suggest that vitamin D deficiency during pregnancy increases MS risk in the offspring, our study does not provide any information as to whether there is a dose response effect with increasing levels of [vitamin D] sufficiency,” the study authors concluded. “Similar studies in populations with a wider distribution of [vitamin D] are needed.”

One of the limitations the authors noted was that maternal vitamin D level during pregnancy does not directly indicate the direct measure of the vitamin D level of exposure in the developing fetus.

In a corresponding editorial, Benjamin M. Greenberg, MD, MHS from the University of Texas Southwestern discussed another limitation of the study. The FMC was created to understand complex biology and disease, and not intended to be a database for MS research, he argued.

“This finding was consistent with a US dietary study that correlated higher levels of vitamin D intake with lower risks of MS, but diverged from two Swedish studies that failed to find an association between early life vitamin D exposure and risk for MS,” Greenberg continued. “One potential limitation of the [current] study is the relatively young age of the cohort children studied (ie, 18-27 years). Given that the average age of MS diagnosis is 30, it is a possible that the control cohort contained individuals with MS who had yet to be diagnosed.”