Vitamin D of the type taken in the US rises for three days and then falls; that's why you take the prescribed 50,000 once a week; it does not "stay" at that level. The prescription type though are only prescribed for a few months until your blood level gets normal and then you can buy less expensive 1,000 or 2,000 a day pills at the drugstore/grocery store, whatever your doctor tells you to buy. Do not take someone else's prescription or pay attention to what they are doing for their body; I don't care if it is your identical twin! :-)

Vitamin D is not addicting at all but can be dangerous (throws off the other vitamins/mineral levels that it needs to fuction well) and you may/may not feel good as you do this week, etc.; take what your doctor prescribes and learn how to get your levels to the right place safely with few side effects, etc. Work with your doctor, it can be dangerous (not from addiction) otherwise. "More" will not make you feel better. Your doctor should do blood tests periodically to check your levels (as too much can seriously injure you).

http://www.vitamindcouncil.org/healt...rs/depression/