A vitamin D deficiency while pregnant could increase the chance of children developing multiple sclerosis (MS) in later life, says a new study published this week in the journal JAMA Neurology.

The results of this new study by the Harvard T.H. Chan School of Public Health add to the growing body of research that vitamin D levels during pregnancy could have an effect on children's health.

For the study, the team looked at 193 individuals -- 163 of them female.

They had all been diagnosed with MS and had mothers who had taken part in the Finnish Maternity Cohort -- a nationwide bio-repository that has collected and stored prenatal serum samples since 1983 in order to study and maintain the populations' health and prevent disease.

The team looked at the blood samples taken from the participant's mothers during pregnancy, 70 percent of which had been collected during the first trimester. The samples were tested for serum 25-hydroxyvitamin D (25[OH]D) levels -- the test used to determine an individual's vitamin D levels.

A level of 20 nanograms/milliliter to 50 ng/mL is considered optimal, while between 10 ng/mL and 19 ng/mL indicates a mild to moderate deficiency. Levels at less than 12.02 ng/mL are considered insufficient.

After comparing the results to a control group, the team found that the children of mothers who were vitamin D deficient during pregnancy had a 90 percent higher chance of developing MS in adulthood compared with children of mothers who were not vitamin D deficient.

"Our results suggest that vitamin D deficiency during pregnancy increases MS risk in the offspring," concluded researchers. They say that correcting this deficiency early in pregnancy could have a beneficial effect.

Vitamin D's added benefits

A study published last month also found that eating vitamin D-rich foods during pregnancy could be beneficial for offspring's health in additional ways, reducing a child's risk of developing allergies by up to 25 percent.

Other previous studies have also linked vitamin D deficiency in adults to conditions such as IBS (Irritable Bowel Syndrome), dementia, and an increased risk of heart attack and stroke.

Vitamin D is obtained from the skin's exposure to sunlight and food sources such as oily fish, including sardines and mackerel, liver, eggs and cod liver oil.