Evaluation of the Clinical Importance and Requirement for Fat-soluble Vitamins

(Young Investigator Award of JSNFS (2017) )

Abstract

Some clinical studies from Europe and the United States have suggested that fat-soluble vitamins play a role in non-communicable diseases. Such studies, however, have seldom been performed in Japan. We have tried to determine the requirement for vitamin D in cross-sectional studies that measured dietary intake and circulating levels simultaneously, and also in intervention studies. Our results have suggested that the requirement for vitamin D is, in fact, three times higher than the current Japanese DRI for avoidance of vitamin D insufficiency, and that intake of a fat-restricted diet is associated with a reduction in absorption of vitamins D and K into the body. As well as vitamin D, we have also revealed that bone is more susceptible to vitamin K deficiency than the liver, and that higher vitamin E intake is significantly associated with a lower prevalence of hypertension.