Abstract
Researches were made on serial and individual fluctuations of the riboflavin metabolism in healthy body by measuring the total riboflavine and its bound form in blood, and the excretion of riboflavine in urine also. Furthermore, the correlation between nicotinic acid and riboflavin metabolism has been studied. The computed average total riboflavin level in blood (12 men and 11 women) is 8.0±1.46 μg/dl, fluctuation of which is rather small both individually and serially through an year. An average level in blood of the bound form of riboflavin (10 men and 11 women) is 6.5±1.11 μg/dl, fluctuation of which is small individually or serially, but through an year some fluctuations are noticed. An average excretion of riboflavin in urine per day (11 men and 7 women) is 1382±603 μg, and its serial fluctuation is comparatively small, while individual or serial fluctuation through an year is found to be remarkable. A slight correlation is noticed between the total riboflavin level in blood and the amount of urinary excretion of nicotinic acid and its metabolized products.
