Abstract
In Japan, two basic texts are used for nutritional guidance, Standard Tables of Food Composition in Japan and Dietary Reference Intakes for Japanese, 2005. The "Food Composition Tables" describe the nutrient values of foods, and "Dietary Reference Intakes" reports the values that humans can use. Synthetic vitamins have been often used in experiments to determine vitamin requirements, and the bioavailability of synthetic vitamins is considered to be 100%. However, the bioavailability of a vitamin from foods may not be 100% because most vitamins existing in nature are bound to proteins, sugars, or other compounds. Although it is necessary to determine the bioavailability of vitamins in food consumed, no method has been established. We introduce a practical method to determine the bioavailability of vitamins in food. In particular, we are also interested in the effects the dietary intake of minerals and micronutrients exerts on the bioavailability of vitamins. We believe that the results of these studies will contribute to the maintenance of public health in Japanese.
