Which vitamin poses the greatest deficiency risk for people who eat no foods from animal source?

Vitamin B12 poses the greatest deficiency risk for people who do not consume animal products, as it is primarily found in animal-derived foods. Vegans and strict vegetarians may struggle to obtain adequate B12 through diet alone, potentially leading to neurological issues and anemia. It is often recommended that those on a plant-based diet consider fortified foods or supplements to ensure sufficient intake of this essential vitamin.