The benefits and challenges of a vegan diet, and the nutrients to plan for, starting with vitamin B12.
A vegan diet leaves out all animal foods: meat, poultry, fish, dairy, eggs and, for many vegans, honey. People choose it for health, for animal welfare, for the environment, or for all three. The Academy of Nutrition and Dietetics, the largest US organization of dietitians, considers appropriately planned vegetarian and vegan diets healthful and nutritionally adequate for all stages of life. The key words are "appropriately planned."
Potential benefits
- More fiber and plants. Vegan diets are usually rich in vegetables, fruit, beans, whole grains, nuts and seeds.
- Heart and metabolic health. Studies link vegetarian and vegan diets with lower LDL cholesterol, lower blood pressure and a lower risk of type 2 diabetes, partly because they tend to be lower in saturated fat.
- Weight. Vegans tend, on average, to have a lower body mass index.
- Environment. Plant-based diets generally have a smaller environmental footprint than diets high in animal foods.
A vegan diet is not automatically healthy, though. Fries, chips, soda and many processed snacks are vegan too. The benefits come from what you eat, not just what you leave out.
Nutrients to plan for
- Vitamin B12. This is the most important one. B12 is found naturally only in animal foods, so vegans need a reliable source: fortified foods, such as some plant milks, breakfast cereals and nutritional yeast, or a supplement. A deficiency can cause anemia and lasting nerve damage, and it can develop slowly over years. Don't rely on seaweed or fermented foods.
- Protein. Easy to get from beans, lentils, peas, tofu, tempeh, soy milk, seitan, nuts and seeds. Eating a variety over the day provides all the essential amino acids.
- Calcium. Choose calcium-fortified plant milks and yogurts, calcium-set tofu, and greens such as kale, bok choy and collards.
- Vitamin D. Sunlight and fortified foods help, but many people need a supplement, especially in winter.
- Iron. Beans, lentils, tofu, fortified cereals and leafy greens provide iron, which is absorbed better when eaten with vitamin C, for example beans with peppers or tomatoes.
- Iodine. Use iodized salt, or ask about a supplement; many plant milks are not fortified with it.
- Zinc. Found in beans, whole grains, nuts and seeds. Soaking, sprouting and fermenting improve absorption. Read more about zinc.
- Omega-3 fats. Walnuts, ground flaxseed, chia and hemp seeds provide ALA; algae-based supplements provide the longer-chain forms found in fish.
Pregnant and breastfeeding women, infants, children and older adults have higher needs for some nutrients, so they should plan a vegan diet with a doctor or registered dietitian.
Practical challenges
- Eating out and traveling can take more planning, though vegan options are now widely available in the United States.
- Hidden animal ingredients such as gelatin, whey, casein and some colorings mean checking labels. See our vegetarian substitutes for gelatin.
- Digestive changes. A sudden increase in beans and fiber can cause gas and bloating; increase them gradually.
- Social situations can be awkward at first; bringing a dish to share helps.
Getting started
Many people find it easier to change gradually: start with a few plant-based meals a week, explore cuisines with long vegetarian traditions, such as Indian, Ethiopian and Middle Eastern cooking, and build a repertoire of meals you enjoy. Read more about vegetarian diets.
Sources
- Position of the Academy of Nutrition and Dietetics: vegetarian diets (Journal of the Academy of Nutrition and Dietetics, 2016)
- Vitamin B12: fact sheet for consumers (NIH Office of Dietary Supplements)
Last reviewed November 2026. This article is general information, not medical advice.