Research shows that people who spend more time in the sun, and those with relatively higher levels of vitamin D are less likely to develop MS than those who do not. Additionally, people with MS who spend significant time in the sun and/or have higher levels of vitamin D have a less severe course of disease and fewer relapses. Bright sunlight helps human skin produce vitamin D. Researchers believe that vitamin D may help regulate the immune system in ways that reduce the risk of MS and autoimmune disorders in general. People from regions near the equator, where there is a great deal of bright sunlight ,generally have a much lower risk of MS than those from temperate areas such as the US and Canada, where sunlight is variable throughout the year.