New research adds to evidence that vitamin D deficiency is associated with MS. Does that mean vitamin D supplementation could prevent the disease?
Going back to at least the 1960s, researchers have noticed something interesting about the distribution of multiple sclerosis (MS): The disease is uncommon close to the equator, where sunlight is most abundant. At higher latitudes, where the sun shines for less time and at a lower intensity, the prevalence of MS increases.
Since sunlight is a necessary ingredient for the synthesis of vitamin D in the skin, the hypothesis that vitamin D deficiency may increase a person’s risk of developing MS was born. New research adds support for this idea, but many questions remain.
Does Vitamin D Play a Role in Prevention of MS?
A study published in October 2017 in the journal Neurology adds to evidence that vitamin D deficiency may increase a person’s risk of developing multiple sclerosis, even many years later. The study focused on a large group of Finnish women who gave blood samples early in pregnancy between 1983 and 2009. The researchers identified 1,092 women who were eventually diagnosed with MS, on average nine years after their blood samples were drawn. They compared the vitamin D levels in their stored blood samples to those of women who didn’t develop MS.
In the study, vitamin D deficiency was more common in the MS group, affecting 58 percent of women who eventually developed MS compared with 52 percent of women who did not. The researchers calculated that women with deficient vitamin D blood levels (defined as less than 30 nanomoles per liter [nmol/l]) had a 43 percent higher risk of developing MS compared with those with adequate levels (at least 50 nmol/l). Vitamin D deficiency was common in this group of women, particularly before 2004, when Finland first started recommending that pregnant women take a vitamin D supplement.
The study’s lead author, Kassandra Munger, a doctor of science in nutritional epidemiology and a research scientist at Harvard T.H. Chan School of Public Health in Boston, says that the results of this study and others show a clear pattern. “If your levels are low, your risk is high, and as your levels increase, your risk seems to decline,” she says.
Previous studies have found similar results, but they were smaller and done in populations with higher average vitamin D levels. For example, another study conducted by Dr. Munger and her colleagues, published in December 2006 in JAMA, found that in U.S. military personnel, high vitamin D levels were associated with a lower risk of MS.
To read this article in its entirity click here: Importance of Vitamin D and MS