Abstract
Annual changes of niacin intake per caputa per day were calculated on the basis of the results of the National nutrition survey form 1970 to 1989 using the Weighted average tables of niacin and also tryptophan contents of protein in foods. The widely adopted convention that 60 mg of trytophan can be taken as equivalent to 1 mg dietary niacin was used. The mean value of the daily niacin intake was 32.5 mg and it exceeded the Japanese Recommended Dietary Allowance of niacin (about 17 mg). Major sources of niacin from food were fishes, cereals and meats. In addition, the investigation were carried out to be clarified the influential factors on niacin intake. From these studies, it was clarified that the intake of niacin may be considerably high even for the low-income families.
