[Clinical application of vitamin A, D and E against malignant tumor in human]

A great number of epidemiologic studies over the last decade have found that vitamin A, D and E are associated with a reduced risk for malignant tumors in human, though these high levels in blood do not always establish the low risk of a variety of malignant tumors. Consequently, either micronutrient supplementation or/and food fortification are going to be recommended as a prevention strategy of malignant tumors to the general population. On the other hand, concerning the clinical application of these vitamins in the treatment for malignant tumors, most recently, active forms of vitamin A and D are said to be effective in some leukemias. Especially, the administration of all-trans retinoic acid in acute promyelocytic leukemia patients has been established to be more effective and safer than conventional chemotherapies to obtain complete remission. In reviewing these studies, more detailed elucidation in clinical usefulness of these vitamins and as their chemoprevention must await further investigations.