Dietary intake of vitamin B6 and concentration of vitamin B 6 in blood samples of German vegans

Abstract

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 B 6 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 and > 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.