Abstract
Vitamin deficiency causes classical deficiency diseases such as beriberi and rickets. Vitamin insufficiency, which is milder than deficiency, is a risk for various chronic diseases, but its significance has not been recognized in Japan. Vitamin D insufficiency is quite common in Japan, and a serious risk for osteoporotic fracture through its unbeneficial effect on bone and muscle. Vitamin K insufficiency is also a risk for fracture. Insufficiency of water-soluble vitamins has been little studied. However, we have reported that vitamin B12 and folate insufficiency is a risk for muscle weakness in the elderly, and vitamin B 1 insufficiency is a risk for heart failure in the elderly.
Although the therapeutic effect of improvement of nutritional status including vitamins is not marked than that of drug treatment, the improvement of nutritional status is far lower in cost and suited for the primary prevention of diseases. Although it is considered that randomized controlled trial is the study with most robust evidence in the evaluation of drug treatment, higher significance should be put on the well-designed cohort studies in evaluating the role of nutrients.
Vitamin insufficiency is quite prevalent, and vitamin requirement is much higher for its insufficiency avoidance than for its deficiency prevention.
