Dietary intake of vitamin B6 and concentration of vitamin B6 in blood samples of German vegans

OBJECTIVE: The study aimed to evaluate the dietary vitamin B6 intake and determine the vitamin B6 concentration in blood samples of German vegans. DESIGN AND SETTING: Cross-sectional study with 33 examination sites all over Germany. Subjects Ninety-three vegans (50 females) with a mean (+/- standard deviation (SD)) age of 43.7 +/- 15.7 years who took no vitamin supplements. METHODS: Dietary intake was assed using a semi-quantitative food-frequency questionnaire. Erythrocyte aspartate aminotransferase activity coefficient (EAST-AC) was calculated as the ratio of stimulated (pyridoxal 5'-phosphate added) to unstimulated activity in blood samples that were provided after an overnight fast. RESULTS: Mean +/- SD vitamin B6 intake was 2.83 +/- 0.98 mg day(-1) and mean +/- SD protein intake was 56.6 +/- 21.7 g day(-1). Of the participants 4% showed vitamin B6 intakes lower than daily recommended intakes for Germany, 16% showed EAST-AC > 1.85, and a further 58% showed EAST-AC of 1.5-1-85. Moderate vegans were affected to a lesser extent than strict vegans. None of the established confounders was a significant predictor of EAST-AC. In logistic regression analyses the contribution of nutriments and cereals to pyridoxine intake was the only predictor of EAST-AC classified as 1.85, respectively. CONCLUSIONS: In spite of the high total intake of vitamin B6, an adequate concentration in blood samples could not be realised for a majority of the participants. Due to the health implications of a marginal pyridoxine status, vegans should be encouraged to include foods with a high bioavailability of pyridoxine, such as beans, lentils and bananas, in the daily diet.