Abstract
Vitamin D-deficiency remains as health and nutritional problems both in developed and developing countries. Vitamin D is essential for bone development and homeostasis of calcium metabolism. Thus, vitamin D-deficiency results in rickets and/or hypocalcemia in children. Vitamin D should be activated by hydroxylation at 2 sites of the vitamin, i.e., 1 and 25 positions of carbons, which occurs in the liver and kidney. The formed 1,25-dihydroxyvitamin D is the active metabolite. The intermediate metabolite is 25-hydorxyvitamin D (25OHD) and its serum concentration reflects the accumulation of vitamin D in the whole body. Therefore, a low level of 25OHD, which is less than 20 ng/ml, indicates vitamin D-deficiency. To prevent vitamin D-deficiency, it is important to eat food such as fish, egg and mushroom (shii-take) containing rather much vitamin D together with calcium. However, fortified milk or juice is recommended in U.S.A. because it is hard to take enough vitamin D from natural foods. Vitamin D-deficiency remains as health and nutritional problems both in developed and developing countries. Vitamin D is essential for bone development and homeostasis of calcium metabolism. Thus, vitamin D-deficiency results in rickets and/or hypocalcemia in children. Vitamin D should be activated by hydroxylation at 2 sites of the vitamin, i.e., 1 and 25 positions of carbons, which occurs in the liver and kidney. The formed 1,25-dihydroxyvitamin D is the active metabolite. The intermediate metabolite is 25-hydorxyvitamin D (25OHD) and its serum concentration reflects the accumulation of vitamin D in the whole body. Therefore, a low blood level of 25OHD, which is less than 20 ng/mL, indicates vitamin D deficiency. To prevent vitamin D-deficiency, it is important to eat food such as fish, egg and mushroom (shii-take) which contain a considerably much amount of vitamin D together with calcium. However, fortified milk or juice is recommended in U.S.A. because it is hard to take enough vitamin D from natural foods.
