CHANGES IN VITAMIN-B-6 STATUS INDICATORS OF WOMEN FED A CONSTANT PROTEIN-DIET WITH VARYING LEVELS OF VITAMIN-B-6

Changes in vitamin B-6 status indicators were evaluated in vitamin B-6 -replete subjects. Ten young women consumed diets providing 85 g prote in/d and 1.03, 1.33, 1.73, and 2.39 mg vitamin B-6/d for 12 or 15 d du ring four successive diet periods; in a second study, six women were f ed diets providing 85 g protein/d and 0.84, 1.14, and 2.34 mg vitamin B-6/d for 10 or 12 d during three successive diet periods. Vitamin B-6 status indicators showing significant differences among intakes inclu ded urinary excretion of 4-pyridoxic acid and total vitamin B-6, pyrid oxal 5'-phosphate and total vitamin B-6 in plasma, ar;d xanthurenic ac id excretion after a 2-g L-tryptophan load. Significant correlations w ere found between vitamin B-6 intake and 4-pyridoxic acid, total vitam in B-6, plasma pyridoxal 5'-phosphate, plasma total vitamin B-6, eryth rocyte alanine aminotransferase percentage stimulation and postload ex cretion of xanthurenic acid and volatile amines (kynurenine plus acety lkynurenine). Depending an the indicator, between 20% and 70% of the s ubjects had inadequate values for 4-pyridoxic acid, total vitamin B-6, plasma pyridoxal 5'-phosphate, and erythrocyte alanine aminotransfera se percentage stimulation at a vitamin B-6 intake of 1.33 mg/d (0.016 mg vitamin B-6/g protein). A ratio of dietary vitamin B-6 to protein > 0.016 mg/g is required for adequate vitamin B-6 status in women.