Adequate vitamin B 12 and folate status of Norwegian vegans and vegetarians

• Published in: British journal of nutrition Vol. 129; no. 12; pp. 2076 - 2083
• Main Authors: Henjum, Sigrun, Groufh-Jacobsen, Synne, Lindsay, Allen, Raael, Ellen, Israelsson, Anna Maria, Shahab-Ferdows, Setareh, Hampel, Daniela
• Format: Journal Article
• Language: English
• Published: England 28.06.2023
• Subjects: Adult; Aged; Biomarkers - blood; Cross-Sectional Studies; Diet, Vegan; Diet, Vegetarian; Dietary Supplements; Female; Folic Acid - administration & dosage; Folic Acid - blood; Folic Acid Deficiency - blood; Folic Acid Deficiency - epidemiology; Homocysteine - blood; Humans; Male; Methylmalonic Acid - blood; Middle Aged; Norway; Nutritional Status; Vegans; Vegetarians; Vitamin B 12 - blood; Vitamin B 12 Deficiency - blood; Vitamin B 12 Deficiency - epidemiology; Young Adult; Norway; B12 dietary intake; Methylmalonic acid; Vegetarians; Homocysteine; Vitamin B12; Folate; Vegans
• ISSN: 0007-1145; 1475-2662
• DOI: 10.1017/S0007114522002987

Plant-based diets may increase the risk of vitamin B deficiency due to limited intake of animal-source foods, while dietary folate increases when adhering to plant-based diets. In this cross-sectional study, we evaluated the B and folate status of Norwegian vegans and vegetarians using dietary B intake, B and folic acid supplement use, and biomarkers (serum B (B ), plasma total homocysteine (tHcy), plasma methylmalonic acid (MMA) and serum folate). Vegans ( 115) and vegetarians ( 90) completed a 24-h dietary recall and a FFQ and provided a non-fasting blood sample. cB , a combined indicator for evaluation of B status, was calculated. B status was adequate in both vegans and vegetarians according to the cB indicator; however 4 % had elevated B . Serum B , tHcy, MMA concentrations and the cB indicator (overall median: 357 pmol/l, 9·0 µmol/l, 0·18 µmol/l, 1·30 (cB )) did not differ between vegans and vegetarians, unlike for folate (vegans: 25·8 nmol/l, vegetarians: 21·6 nmol/l, = 0·027). Serum B concentration < 221 pmol/l was found in 14 % of all participants. Vegetarians revealed the highest proportion of participants below the recommended daily intake of 2 µg/d including supplements (40 . 18 %, < 0·001). Predictors of higher serum B concentrations were average daily supplement use and older age. Folate deficiency (< 10 nmol/l) was uncommon overall (< 2·5 %). The combined indicator cB suggested that none of the participants was B -depleted; however, low serum B concentration was found in 14 % of the participants. Folate concentrations were adequate, indicating adequate folate intake in Norwegian vegans and vegetarians.