Nutritional status of vitamin A, E, C, B1, B2, B6, nicotinic acid, B12, folate, and beta-carotene in young women.

Abstract

To investigate the vitamin status of young Japanese women, dietary intakes of vitamin A, E, C, B1, B2, B6, B12, niacin, folate, and beta-carotene were assessed by a 3-d weighed food record in 150 female students aged 21-22. Whole blood levels of vitamin B1, B2, and nicotinic acid, and serum levels of retinol, alpha-tocopherol, vitamin B6, and beta-carotene were determined by HPLC. Vitamin B12 and folate in serum were measured by chemiluminescence immunoassay, and serum vitamin C was done by dinitrophenylhydrazine method. When the 6th revision RDAs for the Japanese (physical activity level 1) were applied, 46.7% of the females showed sufficient intake for vitamin A, 28.7% for E, 80.7%, for B1, 92.7% for B2, 54.7% for B6, 99.3% for niacin, 76.0% for B12, 34.0% for folate, and 54.0% for C. Fifty-nine percent of total vitamin A (microgRE) intakes were derived from beta-carotene. The mean+/- SD of energy intakes was low, 1.572+/-315 kcal. Significant correlations among intakes of energy and all these vitamins were found. Serum folate and ascorbic acid levels in the females with corresponding vitamin intakes above the RDA were significantly higher than in those with intakes below the RDA. There were significant correlations between blood vitamin levels and vitamin intakes in vitamin B12 (r=0.185), folate (r=0.255), vitamin C (r=0.272), and beta-carotene (r=0.319). Mean blood levels of folate, ascorbic acid, vitamin B2, B12, and beta-carotene were higher in the highest quartile of intake than in the lowest. The 95% confidence intervals of blood vitamin levels obtained from the females with sufficient vitamin intakes were nearly equal to those obtained from all subjects. Only a few females (0.7-4.7%) had their blood vitamin levels below the lower limits. Serum alpha-tocopherol levels were significantly correlated with serum levels of retinol, beta-carotene, and vitamin C. This data suggested that young women should increase suitable dietary food intakes in order to maintain good status of vitamin. Moreover, sufficient amount of physical activity would be expected for prevention of excessive energy intake.