expectant moms can help protect their children from developing multiple sclerosis by taking vitamin d supplements during pregnancy.

researchers say that's because their studies show the risk of m-s is linked to seasonal trends -- and the amount of ultraviolet light that hits the skin.

data shows the risk of m-s is highest for those born in april ... after the winter months when u-v rays are lowest.

experts say their findings make a strong case for supplementing pregnant women with vitamin d.