Vitamin D and MS
Lynne Shinto, ND, MPH, MS Center of Oregon
Correcting vitamin D deficiency may be important to the health of people with MS. Research studies have found that low vitamin D intake and low blood levels of vitamin D may increase the risk of developing MS. Although it is unclear whether vitamin D levels in people with MS are lower than those of people without MS, one small research study found low levels of vitamin D correlated with increased disability in people with MS. It has also been reported that vitamin D levels are lower in people having MS relapses compared with those in remission. Given these findings, it is important to consider vitamin D for MS wellness.
Vitamin D is a fat-soluble vitamin that is found in food and can be made in your body after exposure to ultraviolet (UV) rays from the sun. Sunshine is a significant source of the active form of vitamin D because sunlight triggers vitamin D synthesis in the skin.
Vitamin D exists in several forms. Ergocalciferol (vitamin D2) is the inactive form found in food and cholecalciferol (vitamin D3) is the active form of vitamin D. The liver and kidney help convert vitamin D2 to its active hormone form, vitamin D3. The major function of vitamin D is to maintain normal blood levels of calcium and phosphorus for bone formation and for maintaining bone strength.
Vitamin D3 also can help control the immune system and in one MS study was found to increase the levels of protective anti-inflammatory proteins. Blood levels of vitamin D2 (serum 25-hydroxyvitamin D) are used to determine ‘sufficient’ or ‘deficient’ levels of vitamin D. This can be done with a simple blood test. Results are given as nanograms per milliliter or ng/ml:
For adults the recommended daily intake of vitamin D is 400 IU/day. Taking more than 2000 IU/day may be harmful. High blood levels of vitamin D can cause toxicity and raise blood calcium levels. Side effects include headaches, nausea, vomiting, poor appetite, excessive thirst, weight loss, and heart rhythm abnormalities. One can obtain vitamin D from a number of dietary sources.
Sunshine is the best source of active vitamin D. Although lack of sun during winter months and using sunscreen with SPF > 8 can significantly affect vitamin D levels, it only takes 10 to 15 minutes of sun exposure twice a week to maintain adequate levels of the vitamin. During the dark winter months, cod liver oil or vitamin D3 supplementation can help maintain adequate vitamin D levels.
People with MS should discuss with their health care provider the need to have their blood vitamin D level checked and if low correct it with supplementation. People with MS who are not receiving adequate sun exposure should consider taking vitamin D supplementation after consulting with their health care providers.
For more information, contact your healthcare provider or the National Institute of Health website that addresses dietary supplements at
Last Updated: October 2009