Correlation between niacin equivalent intake and urinary excretion of its metabolites, N'-methylnicotinamide, N'-methyl-2-pyridone-5-carboxamide, and N'-methyl-4-pyridone-3-carboxamide, in humans consuming a self-selected food.
N'-methyl-4-pyridone-3-carboxamide (4-py) is the major metabolite of nicotinamide and nicotinic acid in rats. However, because it is complicated to determine 4-py in humans, there is only one report on its excretion. Recently we developed a method for the microdetermination of 4-py by high-performance liquid chromatography. Urinary excretion of 4-py in Japanese students from Teikoku Women's University who consumed self-selected foods was 7.12 +/- 3.25 mumol/d, which is about one-fourth of N'-methylnicotinamide (MNA) and about one-ninth of N'-methyl-2-pyridone-5-carboxamide (2-py) excretion. The correlation coefficient between daily niacin equivalent (NE) intake and daily 4-py excretion was 0.529, which was about the same as the correlation coefficient between daily NE intake and daily 2-py excretion and which was two times higher than the correlation coefficient between daily NE intake and daily MNA excretion.
Shibata
K
K
Department of Food Science and Nutrition, Teikoku Women's University, Osaka, Japan.
Matsuo
H
H
D000328:Adult; D002851:Chromatography, High Pressure Liquid; D004032:Diet; D002149:Energy Intake; D005260:Female; D006801:Humans; D008832:Microchemistry; D009525:Niacin / Q000008:administration & dosage / Q000378:metabolism*; D009536:Niacinamide / Q000031:analogs & derivatives* / Q000378:metabolism / Q000652:urine; D013223:Statistics as Topic
D009536:Niacinamide; D009525:Niacin; C016590:N(1)-methyl-4-pyridone-5-carboxamide; C005211:N'-methyl-2-pyridone-5-carboxamide; C008472:N-methylnicotinamide