Scientists are taking a look at vitamins and any benefits they might have for multiple sclerosis (MS). Studies indicate that vitamin D may be the one. Vitamin D is made in skin by the conversion of cholesterol to D3 (cholecalciferol) by ultraviolet light. It is known that vitamin D promotes healthy bones, but it is also important to the immune system and therefore potentially an effective supplement to MS treatment.
Studies indicate that vitamin D has the ability to suppress the activation of T cells, which are key players in MS. It has the ability to shift an immune response to a less inflammatory profile. It also has the ability to induce other immune cells known as regulatory T cells (Tregs) to modulate the immune response. Vitamin D has been suggested to dampen the immune system’s feedback loop to limit the negative effects of inflammation.
The RDA of vitamin D is around 200 IU/day and is higher for individuals over 50 (400 IU/day) and age 70 (600 IU/day). A person’s main source of vitamin D is sunlight, and there are a few foods that contain vitamin D, including fish, liver, egg yolks, and reindeer meat. Many foods are enriched with this vitamin as well, such as milk, soy milk, orange juice, and margarine. Enriching these foods with vitamin D was originally done to prevent rickets, but now has additional nutritional and health value.
It’s not always possible to reach the RDA of vitamin D even with a balanced diet. Together with low sun exposure, particularly in the northern hemisphere during winter, most individuals have a vitamin D deficiency. This problem is more acute with dark-skinned individuals, as they are less efficient than lighter skin individuals in synthesizing vitamin D. Even what sunlight we do receive is generally ineffective, due to sun blocks that we use to protect our skin from cancer. The Canadian Community Health Survey (2004) found that somewhere between 80 to 90 percent of adults have an inadequate intake of vitamin D – the poorest track record among all the vitamins.
Earlier studies indicated that low vitamin D levels are linked with a higher risk of developing MS. A study in the Netherlands found that vitamin D protected against the development of MS – but only in women. Vitamin D levels are generally lower in women as compared to men suggesting that women may be more at risk of vitamin D deficiency just as they are at greater risk of developing MS. A study in France discovered that the connection between sun exposure and MS was greater for women than men. This suggests that vitamin D plays a role in MS. However, it has yet to be proven that taking vitamin D supplements or increasing sun exposure will be effective as a therapy.
Some studies indicate that individuals with higher levels of vitamin D have fewer relapses of MS and less disease activity seen on MRI. Other studies have also suggested that people with lower sun exposure or lower vitamin D levels have a higher risk of developing disability associated with the disease. However, there are only four clinical trials that have looked at whether vitamin D works as an actual MS therapy, and the results have not been encouraging. A one-year trial of participants taking an interferon-beta found that adding D3 reduced disease activity on MRI and had a modest effect on disability, but there was no effect on the rate of relapses. Two other studies that used D3 supplements found no effect. One study of vitamin D2 supplements also had no effect, and individuals on higher doses (6,000 IU/day) actually did a bit worse than individuals on lower doses (1,000 IU/day) of D2.