Birth-Month Linked with Lower Vitamin D, Higher Multiple Sclerosis Risk

A new study has found co-relation between birth month and vitamin D levels, along with risk for multiple sclerosis in newborns. Researchers say that summer babies are at a higher risk of having low vitamin D levels and increased risk of multiple sclerosis when compared with babies born around winter.

The study, conducted by researchers from Queen Mary, University of London and the University of Oxford, has now shown how the month of birth affects a person's risk of a condition like multiple sclerosis.

According to PubMed Health, multiple sclerosis is an autoimmune disease that affects the brain and spinal cord. The immune system of the body attacks the protective sheath covering the nerve cells. These damaged cells do not transfer signals properly, causing functional disability. Multiple sclerosis or MS affects women more than men. An estimated 250,000 to 350,000 people in the U.S. have been diagnosed with MS.

Other research has found co-relations between month of birth and Crohn's disease. According to another study, summer babies have increased risk of celiac disease.

"By showing that month of birth has a measurable impact on in utero immune system development, this study provides a potential biological explanation for the widely observed "month of birth" effect in MS. Higher levels of autoreactive T-cells, which have the ability to turn on the body, could explain why babies born in May are at a higher risk of developing MS," co-author Dr. Sreeram Ramagopalan, a lecturer in neuroscience at Barts and The London School of Medicine and Dentistry, part of Queen Mary, said in a news release.

For the study, researchers analyzed cord blood samples from 50 babies born in May and another 50 babies who were born in November.

Researchers measured the levels of autoreactive T-cells and vitamin D levels in the blood samples. T-cells help the body defend itself from an infection by finding and killing foreign particles. But, the autoreactive T-cells begin killing body's own cells, leading to an autoimmune disease. The thymus, an organ of the immune system, regulates these T-cells.

The study found that babies born in May had about 20 percent lower levels of Vitamin D levels when compared to babies born in November, but higher levels of autoreactive T-cells.

"The correlation with vitamin D suggests this could be the driver of this effect. There is a need for long-term studies to assess the effect of vitamin D supplementation in pregnant women and the subsequent impact on immune system development and risk of MS and other autoimmune diseases," Ramagopalan added.

The study is published in the journal JAMA Neurology.