Vitamin B12 and folate status in Spanish lacto-ovo vegetarians and vegans

Journal of Nutritional Science
Q2
Feb 2019
Citations:34
Influential Citations:3
Observational Studies (Human)
81
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Enhanced Details

Methods
Cross-sectional study of healthy adults aged ≥18 years in Madrid, Spain; lacto-ovo vegetarians (n=49) and vegans (n=54); 103 completed analyses; mean age 30.3 ± 7.7 years; 78% women. Exclusion: occasional meat/fish consumption; diagnosed digestive, renal, haematological, endocrine or oncological diseases; eating disorders; pregnancy; lactation and menopause; prior blood donation within 3 months. Procedures included fasting blood analyses (serum vitamin B12, homocysteine, methylmalonic acid, erythrocyte folate, haematological parameters) and an FFQ.
Intervention
Vitamin B12 supplementation; frequency of use at least 2–5 times/month; dosage and duration not specified.
Results
Mean erythrocyte folate was 1704 ± 609 nmol/L. Clinical or subclinical vitamin B12 deficiency detected in 11% (MMA > 271 nmol/L); hyperhomocysteinaemia in 33% (Hcy > 15 μmol/L). Hcy higher in lacto-ovo vegetarians than vegans (P = 0.019). Vitamin B12 supplement users had higher serum B12 and erythrocyte folate, and lower MMA and Hcy (P = 0.012, 0.024, 0.015, respectively). Yoghurts associated with serum B12 adequacy (P = 0.049); eggs with lower Hcy (P = 0.030). Two participants had B12 < 150 pmol/L; MMA elevated in 11 individuals. Using multiple markers (serum B12, MMA, Hcy) detected more abnormal status than serum B12 alone. Conclusion: Vitamin B12 status is generally adequate among Spanish vegetarians, with high folate status; subclinical B12 deficiency detected by MMA and HHcy is relatively common. Supplementation is important for both lacto-ovo vegetarians and vegans; dietary sources alone did not clearly improve B12 markers. Using MMA and Hcy alongside serum B12 provides a better assessment of B12 status.
Limitations
Limitations include categoric dietary data and an unbalanced distribution of vitamin B12 users vs non-users; participants were not representative of the broader Spanish vegetarian population; polymorphisms in vitamin B12/folate pathway genes were not analysed; cross-sectional design limits causal inferences.

Abstract

Abstract Studies on the nutritional status of vegetarians in Spain are lacking. Prevention of vitamin B12 deficiency is the main concern, as dietary sources are of animal origin. The present study aimed to evaluate vitamin B12 and folate status of Sp...