Although researchers have found higher mortality in people who have a lower level of vitamin D, to their surprise they also found it in people that have a high level of vitamin D.
Read the full-length article: Study Suggests Too Much Vitamin D Could Be Bad For Your Health
Individuals with depression are sometimes lower in vitamin D. Inadequate vitamin D is also associated with seasonal depression or SAD, where individuals get down in the dumps in the dark, short winter days due to not enough sunlight. Some research reports that vitamin D supplements can help with SAD.
Read the full-length article: The Vitamin D Depression Association