抄録
Vitamin D was originally known as a vitamin important in calcium metabolism. Vitamin D in the body is obtained with food and also by synthesis in the skin under the influence of sun light UV. Vitamin D needs to be activated/hydroxyrated in liver and kidney for its action in target organs. These situations have not been changed, but its roles in biological system have turned to be wide and deep. One of the newer fields of vitamin D is that of neurological system. Vitamin D insufficiency has been reported to be related to the prevalence of dementia and also to the resilience to stress in the elderly. The relationship between vitamin D and stress in younger generation was suggested in some article, but still under the discussion.
