FAQs about Nutrient Deficiencies in a Vegan Diet 1. What nutrient is most likely to be deficient in a vegan diet? The nutrient most likely to be deficient in a vegan diet is vitamin B12. Since vitamin B12 is primarily found in animal-based foods, vegans who do not supplement with it may develop a deficiency over time. Learn More 2. How can vegans ensure they get enough iron? Vegans can ensure they get enough iron by consuming a variety of iron-rich plant-based foods such as legumes, tofu, tempeh, fortified cereals, and dark leafy greens. Pairing these foods with a source…