Evaluation of vitamin B6 status and RDA in young Koreans

The vitamin B6 status of 294 healthy young Koreans (149 men, 145 women), aged 17-25 years, was estimated to establish the Korean Recommended Dietary Allowance (RDA) for vitamin B6. The dietary vitamin B6 intake was estimated based on a three-day recall method.

The average daily vitamin B6 intake of the subjects was 1.504 +/- 0.825 mg/day (1.567 +/- 0.968 mg/day for men and 1.439 +/- 0.644 mg/day for women). The average ratio of vitamin B6 intake to daily protein intake was 0.019 +/- 0.001 mg/g (0.015 +/- 0.001 mg/g for men and 0.023 +/- 0.001 mg/g for women). Foods from animal and plant sources provided 35.68 +/- 16.16 and 64.18 +/- 16.29% of total vitamin B6. Plasma pyridoxal 5'-phosphate (PLP) concentration of the subjects was 29.26 +/- 16.84 nmol/l (30.52 +/- 20.18 nmol/l for men and 28.21 +/- 13.28 nmol/l for women). The vitamin B6 intake of the subjects whose PLP concentration was >30 nmol/l was 0.019 +/- 0.001 mg vitamin B6/g protein intake (0.017 +/- 0.001 and 0.023 +/- 0.001 mg vitamin B6/g protein intake for men and women, respectively). The intake of vitamin B6 was significantly (p < 0.01-p < 0.001) positively correlated with the intake of all other nutrients. However, no significant correlation was found between PLP concentration and all nutrients examined.

Our suggested adequate Korean RDA for vitamin B6 in young Koreans is 1.6 mg/day or 0.02 mg/g of protein intake in men and 1.5 mg/day or 0.02 mg/g of protein intake in women.