NEWS BRIEF: The simple nutrient that can help soothe wintertime MS flare-ups

The dark days of winter can be tough on all of us. Seasonal depression, colds, and flu are more likely when sunlight is scarce. But for people with multiple sclerosis (MS), increased darkness—and the resulting lack of vitamin D, which the body produces in response to sunlight—can mean major problems.

MS is an autoimmune disease. It causes the immune system to attack the body’s own nerves in the brain and spinal cord. The result is widespread and progressive damage to the nervous system. It can cause debilitating problems with speech, mobility, and mental function.

The link between vitamin D and MS is pretty well known in the medical community. For starters, the condition is much more prevalent in higher latitudes where there’s less sunshine. In addition to that, research has shown that people who get less sun exposure regardless of latitude are more likely to develop MS than those who get more.

But it’s not just the risk of developing MS that hinges on sun exposure. For those who already have MS, relapse becomes more likely during winter months, according to a recent study.

The study, published in the September 2016 issue of European Journal of Clinical Nutrition uncovered a link between plummeting vitamin D levels in winter and a higher likelihood of suffering relapses and disability in people with MS.

The researchers measured serum vitamin D concentrations in people with relapsing-remitting MS being treated with immune-modulating drugs and compared it against control subjects. They found that the people with the most severe symptoms and the most relapses were those who had the lowest vitamin D concentrations in their blood.

The bottom line: Higher vitamin D levels protect against relapses. People with MS should be supplementing with vitamin D3 throughout the winter, especially if they life at higher latitudes. But given the fact that vitamin D protects against MS—and a number of other health woes— we’d all be wise to up our intake during winter months.

You need to supplement with at least 2,000 to 5,000 IU of vitamin D3 per day in order to maintain healthy levels even in the summer. In the winter, those daily requirements may go up to as much as 10,000 IU per day. (That’s how much I take myself.)

You won’t know for sure until you get tested. So, once again, if you haven’t had your levels measured lately, ask your doctor to check them today. (You can also order your own vitamin D testing kit through a company called Direct Labs. Just visit their website at Or call 800-908-0000 and reference account code: R-OVH.)


“Sun exposure and multiple sclerosis risk in Norway and Italy: The EnvIMS study.” Mult Scler. 2014;20(8):1042-1049.

“Association of seasonal serum 25-hydroxyvitamin D levels with disability and relapses in relapsing-remitting multiple sclerosis.” Eur J Clin Nutr. 2016;70(9):995-999.