Determination of vitamin B-6 estimated average requirement and recommended dietary allowance for children aged 7-12 years using vitamin B-6 intake, nutritional status and anthropometry1

Abstract

The Estimated Average Requirement (EAR) and Recommended Dietary Allowance (RDA) of vitamin B-6 for children were recently estimated by extrapolating from adult values because of limited available information. To determine vitamin B-6 requirements and provide recommendations for intakes, vitamin B-6 intake, nutritional status and anthropometry of 168 healthy children (79 boys and 89 girls) were studied in Tainan, Taiwan. Direct and indirect vitamin B-6 status indicators were measured in plasma, erythrocytes and urine. Anthropometric data of children in this study were similar to those of the first Nutrition and Health Survey in Taiwan (NAHSIT) conducted in 1993-1996. The plasma pyridoxal phosphate (PLP) concentration of each child was ≥30 nmol/L, indicating an adequate vitamin B-6 status. Daily dietary vitamin B-6 intakes of boys and girls were 0.80 ± 0.16 and 0.74 ± 0.16 mg/d, respectively. Daily dietary vitamin B-6 intakes of children who had adequate urinary 4-pyridoxic acid (4-PA) (>3.0 μmol/L), erythrocyte alanine aminotransferase activity coefficient (EALT-AC) (<1.25) and aspartate aminotransferase activity coefficient (EAST-AC) (<1.8) were not different from those of children who had adequate plasma PLP, although the percentages of adequacy for urinary 4-PA, EALT-AC and EAST-AC ranged from 20 to 91%. Vitamin B-6 status indicators were strongly correlated with vitamin B-6 intake. Adequate values of PLP, EALT-AC, EAST-AC and urinary 4-PA were used to determine the EAR according to Dietary Reference Intake (DRI) committee methodology. We determined the vitamin B-6 EAR (RDA) for boys and girls aged 7-12 y to be 0.84 (1.01) and 0.75 (0.89) mg/d, respectively.