Bioavailability of vitamin B-6 in young and older men.
Various indexes of vitamin B-6 status have been shown to be reduced with aging. The cause for the apparent reduced vitamin B-6 status is not well understood. For direct assessment of how the bioavailability of vitamin B-6 is affected by aging, [2H]pyridoxine was orally administered to healthy men, aged 20-30 and 60-70 y, who were fed a controlled diet. No differences were observed in plasma pyridoxal 5'-phosphate concentration, erythrocyte aspartate aminotransferase activity, or plasma alkaline phosphatase activity between the two age groups. There were no age-related differences in the urinary excretion of total or [2H]4-pyridoxic acid during a 3-d collection period. Results from this study indicate that the bioavailability of vitamin B-6 is not altered with aging in free-living, healthy adult men.
Ferroli
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CE
Department of Foods and Nutrition, Purdue University, West Lafayette, IN 47907.
Trumbo
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PR
D000328:Adult; D000368:Aged; D000375:Aging / Q000378:metabolism*; D000469:Alkaline Phosphatase / Q000097:blood; D001219:Aspartate Aminotransferases / Q000097:blood; D001682:Biological Availability; D002851:Chromatography, High Pressure Liquid; D004912:Erythrocytes / Q000201:enzymology; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008297:Male; D008875:Middle Aged; D011732:Pyridoxal Phosphate / Q000097:blood; D011735:Pyridoxic Acid / Q000652:urine; D011736:Pyridoxine / Q000378:metabolism* / Q000493:pharmacokinetics*
D011735:Pyridoxic Acid; D011732:Pyridoxal Phosphate; D001219:Aspartate Aminotransferases; D000469:Alkaline Phosphatase; D011736:Pyridoxine