The effect of dietary glycosylated vitamin B-6 on the bioavailability of vitamin B-6 was determined in 4 women. A 44-d metabolic-balance diet study was divided into a preliminary 8-d adjustment period followed by two 18-d experimental periods. The subjects were divided into two groups in a crossover design to compare the effect of low- and high-glycosylated vitamin B-6 diets on the bioavailability of vitamin B-6. The total vitamin B-6 content in the low- and high-glycosylated vitamin B-6 diets was 1.506 mg (8.91 nmol) and 1.897 mg (11.22 μmol), respectively, in which 11 and 22% was the glycosylated form, respectively. Daily 24-h urine specimens were collected by each subject throughout the study; 7- or 8-d fecal collections were made at the end of each experimental period. The four subjects' mean urinary total vitamin B-6 excretion during the low- and high-glycosylated vitamin B-6 periods was 0.76 ± 0.20 and 0.67 ± 0.06 μmol/24 h, respectively; fecal total vitamin B-6 excretion was 2.98 ± 0.43 and 4.56 ± 0.87 μmol/24 h, respectively. Expressed as % of total vitamin B-6 intake, the mean urinary total vitamin B-6 excretion was lower during the high-glycosylated vitamin B-6 period (6.0 ± 0.8%) than during the low-glycosylated vitamin B-6 period (8.5 ± 2.4%); in contrast, their mean fecal vitamin B-6 excretion during the high-glycosylated vitamin B-6 period (40.7 ± 8.2%) was greater than the low-glycosylated vitamin B-6 period (33.6 ± 5.4%). In addition, approximately 11% of ingested glycosylated vitamin B-6 was excreted in urine. These results suggest that dietary glycosylated vitamin B-6 is not completely bioavailable to humans, and the extent of its utilization is not affected by dietary glycosylated vitamin B-6 intake. / Graduation date: 1993

Graduation date: 1991