Assessment of vitamin B6 status using food intake records and analysis of urinary 4-pyridoxic acid and xanthurenic acid in female university students

• Published in: Nihon Eiyō, Shokuryō Gakkai shi Vol. 57; no. 3; pp. 133 - 140
• Main Authors: Shibuya, M. (Shikoku Univ., Tokushima (Japan)), Bando, K, Okada, M
• Format: Journal Article
• Language: Japanese
• Published: Japan Society of Nutrition and Food Science 2004
• Subjects: FOOD INTAKE; MANKIND; RECOMMENDED DIETARY ALLOWANCES; urinary 4-pyridoxic acid; vitamin B6; vitamin intake; VITAMINS; VITAMINS B; WOMEN; xanthurenic acid; young women
• ISSN: 0287-3516; 1883-2849
• DOI: 10.4327/jsnfs.57.133

We assessed the nutritional status of vitamin B6 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 B6 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 B6 intake level of the subjects was 1.00±0.37mg/day and the ratio of vitamin B6 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 B6 requirement was calculated on the basis of bioavailability (75%) and the 0.014mg/g level stipulated in the RDA. The individual recommended vitamin B6 allowance was calculated as the individual vitamin B6 requirement ×1.2. The subjects were divided into three groups: a L group (n=70, 50% of subjects) below the individual vitamin B6 requirement, a M group (n=27, 19%) meeting the individual vitamin B6 requirement but below the individual recommended vitamin B6 allowance, and a H group (n=42, 30%) above or equal to the individual recommended vitamin B6 allowance. In the L group, vitamin B6 intake (0.74±0.22mg) and the ratio of vitamin B6 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.