[Nutritional and biochemical studies on vitamin D and its active derivatives].
We have performed nutritional and biochemical studies on vitamin D and its active derivatives and the following results are obtained. 1. Since recent studies have revealed that dietary supplement of vitamin D (D2 and D3) and calcium is effective for preventing osteoporosis, a simplified routine method for determination of vitamin D in foods is established and applied to the assay on the contents of vitamin D in various kinds of Japanese foods. 2. A simplified routine method for simultaneous determination of vitamin D and its metabolites in the plasma and milk is established and applied to nutritional and clinical studies. 3. Physiological activities of two kinds of novel vitamin D3 derivatives, 22-oxa-1 alpha, 25-dihydroxyvitamin D3 (22-oxa-1,25(OH)2D3, OCT) and 2 beta-(3-hydroxypropoxy)-1,25(OH)2D3 (ED-71) have been studied. OCT, which has less calcemic and stronger cell differentiation activities than 1,25(OH)2D3, is a candidate for curing leukemia and other cancers without hypercalcemia. We have clarified that the property is due to its weak binding affinity for vitamin D binding protein and rapid turn-over in the body and rapid excretion into bile. On the other hand, ED-71, which has stronger effects on intestinal calcium absorption and longer bone turn-over than 1,25(OH)2D3, is a candidate for curing osteoporosis. We have clarified that the properties are due to stronger binding affinity for DBP and longer half-life than 1,25(OH)2D3.
Kobayashi
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Department of Hygienic Sciences, Kobe Pharmaceutical University, Hyogo, Japan.
D000818:Animals; D044466:Asian People; D001842:Bone and Bones / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D005260:Female; D005504:Food Analysis; D006801:Humans; D007564:Japan; D008297:Male; D009749:Nutrition Surveys; D010024:Osteoporosis / Q000517:prevention & control; D012621:Seasons; D014807:Vitamin D / Q000378:metabolism / Q000502:physiology
D014807:Vitamin D; D002118:Calcium