The Claim
Vitamin B12 deficiency is common in long-term vegans due to the absence of bioavailable vitamin B12 in unfortified plant-based foods, and this deficiency increases the risk of developing megaloblastic anemia and irreversible neurological damage; reliable supplementation or consumption of fortified foods is required to prevent these outcomes.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
Long-term vegans who do not consume fortified foods or supplements often develop vitamin B12 deficiency, which leads to megaloblastic anemia and irreversible neurological damage.
See the scientific wording
Vitamin B12 deficiency is common in long-term vegans due to the absence of bioavailable B12 in unfortified plant foods, increasing the risk of megaloblastic anemia and irreversible neurological damage, and requires reliable supplementation or fortified foods for prevention.
Without enough vitamin B12, the body cannot make DNA properly in cells that divide quickly, like blood cells and nerve cells. This causes red blood cells to grow too large and malfunction, leading to anemia, and damages the protective coating around nerves, causing permanent nerve problems.
What the research says
1 studyVegans who don’t take B12 supplements or eat fortified foods are more likely to be low in B12, which can cause anemia and nerve problems — but taking supplements or eating fortified foods fixes it.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.