Patient InformationVitamin D and Multiple Sclerosis

By: Dr. Deneb Bates

The connection between vitamin D and MS risk was first investigated because of the unusual distribution of MS throughout the world.  People who live near the equator and are regularly exposed to high levels of sunlight have a lower risk of developing MS, while people living farther from the equator, with low sun exposure, have a higher risk of developing MS.  Vitamin D is a nutrient that is not abundant in food, but is naturally made when skin is exposed to ultraviolet light from the sun.  More recently, studies have shown that vitamin D impacts the function of the immune system in many ways that may help prevent the development or progression of certain diseases, particularly MS.

While moderate sun exposure may be the best source of vitamin D, people living in northern climates aren’t able to make enough vitamin D from sunlight in the wintertime.  Because of this, most MS patients need a vitamin D supplement to maintain optimal body levels of vitamin D year-round. 

Vitamin D is a fat-soluble vitamin that can be toxic at very high doses.  The best way to optimize vitamin D levels for people with MS, or at high risk of developing MS, is to have your vitamin D level tested by your doctor.  Knowing your level will allow your doctor to make an individualized dose recommendation to keep your body supplied with a safe but optimal amount of vitamin D. The physicians at the IMSMP recommend that most patients have at least a moderate level of 25-hydroxy vitamin D (generally between 50-60 ng/ml).