Medicine & Research

The Sunshine Vitamin: Vitamin D and MS

By Elizabeth Yarnell, CNC, CNHP
You might already know that vitamin D is essential for healthy bones and teeth, but did you realize that it plays a role in maintaining a healthy immune system, too?
A connection between MS and vitamin D deficiency has been studied for decades. Low blood levels of vitamin D are common among the MS population, and according to recent reports, as many as 80 percent of people with MS don’t get enough of it in their diets. In fact, current research findings suggest that vitamin D may positively influence the immune systems of people with MS.
Vitamin D is considered a hormone as well as a vitamin for its role in body processes. It works together with calcium and phosphorus to strengthen bones and teeth, and aids in assimilation of vitamin A. Vitamin D may also help eye problems such as conjunctivitis, myopia, and cataracts.
The “sunshine vitamin” can be manufactured by the body when energy in the sun’s rays initiates a chemical reaction in exposed skin that produces the active form of the vitamin: vitamin D-3. Vitamin D is also available in supplements and foods. Look for supplements that contain vitamin D-3, the active, natural form as it occurs in liver oils, rather than D-2 (calciferol), a synthetic form that may not provide the same beneficial effects. Natural vitamins derived from whole foods are always the better choice and offer higher absorption rates.
Sun Exposure Decreases Risk of MS
In 2003, the British Medical Journal reported that children and adolescents who had high sun exposure had a decreased risk of MS later in life. “Sun exposure during childhood and early adolescence seemed to be most effective against MS, and higher sun exposure during winter months, when minimum ultraviolet radiation and vitamin D exposures occur, was particularly important,” researchers wrote. 
Investigators at the University of Wisconsin - Madison saw similar results in an animal model of MS called experimental autoimmune encephalomyelitis (EAE). Their studies showed that low-sunlight conditions can result in a higher risk of EAE in mice. These findings correlate with the reality that MS is almost nonexistent along the equator, while incidence rates increase as you move farther in each direction. More sunlight near the equator allows the body to produce more vitamin D, which scientists have hypothesized may account for the lower rates of MS there.
Just five to 30 minutes of casual sunlight exposure each day is enough to provide most people with the vitamin D they need, but 40 percent of people with MS may not get any sunlight exposure during an average week. Because clothing covering the skin and sunscreen can affect vitamin D absorption, the benefits of sun exposure have to be balanced with the risks. While some time in the sun may be helpful, burns or long-term exposure may be harmful to your health. UV radiation is believed to contribute to skin cancers, including melanoma.
To Supplement or Not To Supplement?
When researchers compiled data from two large studies that tracked almost 200,000 women over several decades, they found that the risk of developing MS was lower in those who took in at least 400 International Units of vitamin D daily.
Alberto Ascherio’s team at the Harvard School of Public Health studied blood samples of U.S. Army and Navy personnel taken before they developed MS and found that those with the highest levels of vitamin D had a 62 percent reduced risk of developing the disease.
Even though he reported that “the idea that we could prevent many cases of MS with vitamin D is extremely appealing,” Ascherio proposed further study before everyone jumps on board. Because vitamin D is a fat-soluble vitamin, overdosing can cause fatigue, kidney damage, high blood pressure, and multiple other toxic effects. Diarrhea and the desire to sleep all day may be early indications of vitamin D overdose.
Most experts agree, however, that the government’s recommended daily intake of 200 International Units of vitamin D up to age 50, 400 IUs up to age 70, and 600 IUs for those older than 70, may not be enough. Allen Bowling, M.D., Ph.D., author of Alternative Medicine and Multiple Sclerosis, recommends that vitamin D supplements of up to 600 IUs be taken daily together with 1,000 to 1,200 IUs of calcium for better absorption. The Harvard team suggests 1,000 to 2,000 IUs of vitamin D each day may be better.
Before undertaking any new supplement regime, be sure to consult with your healthcare professional and consider testing vitamin D levels in your blood to determine an optimum supplementation schedule.
Editor's note:
The role vitamin D plays in MS has not yet been established. While adequate levels of D in childhood may be preventive against MS and other health conditions, the benefit of the vitamin later in life – if any – is still under review. Despite the remaining questions, getting the recommended amount of vitamins and minerals is part of your total health. For help knowing the nutrients you should be getting, visit
Award-winning author Elizabeth Yarnell responded to her MS diagnosis by pursuing better health through better nutrition. A Certified Nutritional Consultant and Natural Health Professional, her efforts resulted in the invention of a patented cooking method introduced in Glorious One-Pot Meals: A Revolutionary New Quick and Healthy Approach to Dutch Oven Cooking (Broadway Books, January 2009). Elizabeth’s book tour includes many speaking events designed to raise funds and awareness for MS while giving those affected by MS real strategies for building healthier bodies. Find out more at
(Last reviewed 7/2009)