We assessed the nutritional status of vitamin B
6 in 139 female university students using selfrecorded food intake tables, and analyzed 4-pyridoxic acid (PiA) and xanthurenic acid (XA) excreted into urine. The food survey revealed that the dietary intake of vitamin E, vitamin B
6 and vitamin C was lower than that stipulated in the 6th revision of the Japanese Recommended Dietary Allowance (RDA), the RDA sufficiency percentages being 93, 83 and 81%, respectively, while the intake of other vitamins exceeded the RDA guidelines. The vitamin B
6 intake level of the subjects was 1.00±0.37mg/day and the ratio of vitamin B
6 to protein was 0.018±0.005mg/g. We calculated the individual recommended protein allowance using the body weight of each subject, and the individual vitamin B
6 requirement was calculated on the basis of bioavailability (75%) and the 0.014mg/g level stipulated in the RDA. The individual recommended vitamin B
6 allowance was calculated as the individual vitamin B
6 requirement ×1.2. The subjects were divided into three groups: a L group (
n=70, 50% of subjects) below the individual vitamin B
6 requirement, a M group (
n=27, 19%) meeting the individual vitamin B
6 requirement but below the individual recommended vitamin B
6 allowance, and a H group (
n=42, 30%) above or equal to the individual recommended vitamin B
6 allowance. In the L group, vitamin B
6 intake (0.74±0.22mg) and the ratio of vitamin B
6 to protein (0.015±0.004mg/g) were the lowest (
p<0.0001) of the three groups. The urinary PiA content of the L group (3.26±1.33μmol/day) was significantly lower (
p<0.05) than that of the H group, and the ratio of XA to protein (0.64±0.34μmol/g) was higher (
p<0.001) than that of the H group.
View full abstract