Abstract
Research was made on serial and individual fluctuations of the nicotinic acid metabolism in healthy body by measuring the nicotinic acid level in blood and the excretion of nicotinic acid, N'-methylnicotinamide and N'-methyl-3-carboxylamide-6-pyridone in urine. (1) The average nicotinic acid level in blood of 12 men and 12 women was 0.46±0.080 mg/dl, and the individual or serial fluctuation was rather small. (2) The average excretion of nicotinic acid in urine per day (12 men and 10 women) was 2.4±0.71mg, which had some relation with the nicotinic acid level in blood, and it showed less individual fluctuation than that of N'-methyl-nicotinamide and N'-methyl-3-carboxylamide-6-pyridone. (3) The average excretion of N'-methylnicotinamide in urine per day (12 men and 10 women) was 4.6±1.47mg and that of N'-methyl-3-carboxylamide-6-pyridone (12 men and 6 women) was 9.1±2.98mg. The individual and dietary fluctuations were remarkable. (4) Proportions of excretion of the above three compounds in urine were nicotinic acid 100,N'-methylnicotinamide 192,and N'-methyl-3-carboxylamide-6-pyridone 379.
