Science Buddies: "Ask an Expert"

Hy guys hope u can help me answer this question

For simple research, an excellent place to start is with an Internet search with Google or some other search engine.

So, going to http://www.google.com/ and typing in:
vitamin d health disease
gives many matches, and the first one, the Dietary Supplement Fact Sheet on Vitamin D, seems to be exactly the sort of information that you are looking for.

Castrol,

You may also wish to repost this question on the life sciences section of the Science Buddies "Ask and Expert" website. You may find they can help you with further advice.