PLASMA PYRIDOXAL 5'-PHOSPHATE CONCENTRATIONS AND URINARY 4-PYRIDOXIC ACID - CREATININE RATIOS OF ADULTS OF VARIOUS ETHNICITIES

The vitamin B-6 status of adults, mostly international graduate studen ts having various ethnic backgrounds, 22-47 years, who were participan ts in five different metabolic studies for 8 weeks was determined. The re were 15 men and 24 women; 7 were Caucasians from North America, 12 Hispanics from Latin America, 6 Indians from Asia, 13 Orientals from A sia, and one black from Africa. Their daily intakes (mean +/- SD) of p rotein and vitamin B-6 as analyzed were: 68.5 +/- 19.0 g and 1.36 +/- 0.43 mg, respectively. Plasma pyridoxal 5'-phosphate concentrations of all the subjects in the five studies and urinary 4-pyridoxic acid:cre atinine ratios of all the subjects in the three studies in which this parameter was assessed were indicative of adequate vitamin B-h status. These values were similar for subjects across sex, metabolic study, a nd ethnic groups. Vitamin B-6 requirements of these men and women of d ifferent ethnicities seemed to be satisfied by daily consumption of 1. 36 +/- 0.43 (mean +/- SD) mg of the vitamin and 68.5 +/- 19.0 g of pro tein for 8 weeks.