On a vegetarian diet (very common in India), a B12 shortfall is a real, well-documented risk — unlike vitamin D, which can also be corrected by sunlight, plant-based diets contain essentially no B12 without fortified foods or a supplement, so for a strict vegetarian or vegan this isn't optional.

noli's read

Source: a meta-analysis (Bakaloudi et al., Nutrition Bulletin, 2024, 19 studies) and a review of B12 shortfall prevalence among vegetarians (18 studies, 2013). Evidence type: a meta-analysis of blood biomarkers (serum B12, homocysteine, methylmalonic acid) in vegan/vegetarian adults versus omnivores. The data show significantly lower B12 and more frequent functional-deficiency markers among vegans, with reported prevalence ranging from 5-52% depending on the study and cutoffs used — clearly higher than in omnivores. B12 supplementation effectively corrects these markers in supplemented vegans, confirming the causal link (the added vitamin does correct the measured gap). The post's content — laying out the best food sources and supplements for B12 and vitamin D for a largely vegetarian Indian audience — matches a genuinely documented at-risk population. Direction: causal, supplementation corrects a measured biological marker.

the sources

No named source held this one up — that absence is part of the verdict.