Vitamin B12 Status in Vegan and Vegetarian Seventh-Day Adventists: A Systematic Review and Meta-Analysis of Serum Levels and Dietary Intake.

This systematic review and meta-analysis evaluated vitamin B12 intake and serum status among Seventh-day Adventists following plant-based diets compared to omnivore controls to assess their risk of vitamin B12 deficiency. Analyzing four observational studies with 1,994 participants from the United States, New Zealand, and Australia, the review found no significant differences in serum vitamin B12 levels or daily intake between plant-based Adventists and omnivores, likely due to widespread use of fortified foods and supplements. Despite these findings, the included studies were limited by small numbers, cross-sectional design, and geographic concentration, highlighting the need for more diverse, longitudinal research to confirm these results across broader Adventist populations. The review underscores the importance of supplementation and fortified food consumption for maintaining adequate vitamin B12 status among vegan and vegetarian Adventists.