Why Vegetarians Are at Particular Risk
B12 exists almost exclusively in animal-derived foods: meat, fish, eggs, and dairy. A 2017 study published in the Journal of Nutritional Science found that vegetarians in South Asia had a B12 deficiency prevalence of up to 73%, compared with under 20% in omnivores from the same populations. For Indians who follow a strictly plant-based diet, or who eat dairy irregularly, the body's stored B12 can deplete over two to five years without any obvious signal. By the time symptoms appear, the deficiency is often moderate to severe.
