What is wrong with me? (Symptoms included)?

I willl start out with a story first then i will tell u what is wrong. Me and my sibilings went to our family doctor for a reg check up, me an my sister told her we always feel tired and sleepy, when we sleep it is very hard to wake us up. She told us the purpose is b/c we have a low vitamin D level. so it is the same thing, many people who live in canada or areas that is cloudy or night is much longer then day people often found with low vitamin d level b/c we get vitamin d from sunlight mostly, and since there isnt enought sunlight we have a lack of vitamin d. the doctor told us to eat eggs, milk containing food like cheese, etc. or the easier way is to do the samething i did i went to a pharamcy and bought vitamin d pills. i am not sure what theu call them. I am warning u if u dont get enough vitamin d u will have much more problems.