B-Vitamin Status and Concentrations of Homocysteine in Austrian Omnivores, Vegetarians and Vegans

• Published in: Annals of nutrition and metabolism Vol. 50; no. 6; pp. 485 - 491
• Main Authors: Majchrzak, D., Singer, I., Männer, M., Rust, P., Genser, D., Wagner, K.-H., Elmadfa, I.
• Format: Journal Article
• Language: English
• Published: Basel, Switzerland S. Karger AG 01.01.2006; Karger
• Subjects: Adult; Aged; Alcohol Drinking - epidemiology; Anthropometry; Aspartate Aminotransferases - blood; Austria; Biological and medical sciences; Diet; Diet, Vegetarian; Feeding Behavior; Female; Folic Acid - blood; Glutathione Reductase - blood; Homocysteine - blood; Humans; Hyperhomocysteinemia - epidemiology; Hyperhomocysteinemia - etiology; Male; Meat; Medical sciences; Metabolic diseases; Middle Aged; Nutrition; Original Paper; Pyridoxal Phosphate - blood; Pyridoxic Acid - urine; Riboflavin - blood; Riboflavin - urine; Riboflavin Deficiency - epidemiology; Riboflavin Deficiency - etiology; Surveys and Questionnaires; Thiamine - blood; Thiamine - urine; Transketolase - blood; Vegetables; Vegetarianism; Vitamin B; Vitamin B 12 - blood; Vitamin B 12 Deficiency - epidemiology; Vitamin B 12 Deficiency - etiology; Vitamin B 6 - blood; Vitamin B Complex - blood; Vitamin B Deficiency - epidemiology; Vitamin B Deficiency - etiology; Austria; Vegetarians; Homocysteine; Omnivores; Vegans; B-vitamins; Sulfur containing aminoacid; Thiol; Homocystein; Nutrition; Vegetalian diet; B-Vitamins; B-vitamins, Homocysteine; Concentration; Vegetarians, Vegans
• ISSN: 0250-6807; 1421-9697
• DOI: 10.1159/000095828

Background: A vegetarian diet is considered to promote health and longevity and reduce the risk of cardiovascular diseases and cancer. However, a vegetarian diet may be deficient in some nutrients. Exclusion of animal products in vegetarian diets may affect the status of certain B-vitamins, and further cause the rise of plasma homocysteine concentration. Objective: The nutritional status of various B-vitamins (B 1 , B 2 , B 6 , B 12 , folic acid) and the concentration of homocysteine in blood plasma of omnivores (n = 40), vegetarians (n = 36) and vegans (n = 42) in Austria was evaluated. Methods: The evaluation was done using the functional parameters erythrocyte transketolase (ETK), glutathione reductase (EGR) and glutamic oxaloacetic transaminase (EGOT) activation coefficients. Enzyme activity was measured photometrically. The quantity of vitamins B 1 , B 2 and B 6 in urine and the concentrations of vitamin B 6 and homocysteine in plasma were determined by HPLC methods with fluorescence detection. Plasma concentration of vitamin B 12 and folic acid were measured with radioimmunoassay. Results: Most of the subjects showed a satisfying vitamin B 1 status. Vegans presented a significantly lower mean plasma vitamin B 12 concentration than omnivores and vegetarians and deficiency in 2.4% of the volunteers but the highest mean value of plasma folate among the investigated groups. A deficient status of folate was found in 18% of omnivores and in approximately 10% of vegans and vegetarians. The status of riboflavin is considered to be deficient in about 10% of omnivores and vegetarians and in over 30% of vegans. According to the activation coefficient of GOT, approximately one third of all subjects showed vitamin B 6 deficiency. Elevated homocysteine concentration in plasma was observed in 66% of the vegans and about 45–50% of the omnivores and vegetarians. Vegan subjects had significantly higher mean plasma homocysteine levels than omnivores. Conclusion: Thiamin and folate need not be a problem in a well-planned vegan diet. Vitamins B 12 and B 2 may need attention in the strict vegan diet, especially regarding elevated homocysteine levels in plasma. Pyridoxine status appeared to be independent of the diet.