Vegan Diet: What It Is, Key Nutrients and How to Plan It

A vegan diet is an eating pattern that leaves out all foods of animal origin: meat, poultry, fish and shellfish, but also eggs, dairy and ingredients made from animals, such as gelatin. What remains is vegetables, fruits, grains, beans, lentils, soy foods, nuts and seeds. The Academy of Nutrition and Dietetics, a professional body for dietitians, says a well-planned vegan diet can meet nutrient needs in adults, and the federal Dietary Guidelines name the nutrients that need the most attention. This guide answers what is a vegan diet, what the experts actually said, and which vegan diet nutrients to plan for, with USDA data for the foods that supply them.

Peptide Labs does not sell food or meal plans, and this article links no product. It is general nutrition information, not medical advice.

What is a vegan diet?

The Academy’s 2025 position paper defines it simply: vegetarian patterns exclude meat, poultry and seafood, and vegan patterns exclude all foods of animal origin. In practice, that means reading ingredient lists as well as avoiding obvious animal foods. Whey, casein and lactose come from milk; egg whites hide in baked goods; and gelatin, made from animal collagen, turns up in gummies, marshmallows and capsules, as our guide to gelatin explains. Our vegan collagen guide covers why true collagen always comes from animals.

Vegan is the strictest of the vegetarian patterns. If you still eat eggs or dairy, our sibling guide to the vegetarian diet sorts out the different types, and our guides to the flexitarian diet and the pescatarian diet cover patterns that include some meat or fish.

What the Academy of Nutrition and Dietetics says about a vegan diet

Two position papers are often quoted, and they differ in an important way:

• 2016 position: the Academy said appropriately planned vegetarian diets, including vegan diets, are healthful and nutritionally adequate and may provide health benefits, and that they suit all stages of life, from pregnancy and infancy to older age and athletes. It linked vegetarian and vegan eating with lower rates of several chronic conditions in population studies, and it stated that vegans need reliable sources of vitamin B12, such as fortified foods or supplements.
• 2025 position: the updated paper, approved in January 2025 and in effect until the end of 2032, covers adults who are not pregnant or breastfeeding. It says appropriately planned vegetarian and vegan patterns can be nutritionally adequate and can offer long-term health benefits, mainly in heart and metabolic health measures, and it gives registered dietitians a central role in planning.

Two words carry the weight in both papers: appropriately planned. Neither says that any meal without animal foods is automatically healthy. A 2026 letter in the same journal also disputed one detail, arguing that the 2025 paper wrongly linked vegetarian and vegan diets with vitamin D deficiency, which shows that experts still debate specific nutrients.

Vegan diet nutrients to plan for

The Dietary Guidelines for Americans, 2025 to 2030, say vegan diets show broader nutrient shortfalls than vegetarian diets and advise monitoring status periodically, especially for iron, vitamin B12, vitamin D, calcium and iodine. Here is what the NIH Office of Dietary Supplements (ODS) says about each nutrient most often discussed.

• Vitamin B12: ODS says natural food sources are limited to animal foods, and plant foods do not naturally contain it. Fortified breakfast cereals and fortified nutritional yeast are readily available sources, and fortified foods or supplements can substantially lower the chance of deficiency. See our guides to B12 in foods, nutritional yeast and vitamin B12.
• Calcium: ODS lists people who avoid dairy, including vegans, as having a higher risk of low calcium intake. Calcium-set tofu, fortified soy beverages and some greens help; our calcium foods guide has more.
• Vitamin D: ODS says deficiency is more common in people who follow an ovo-vegetarian or vegan diet. Few foods supply it; see our vitamin D foods guide.
• Iron: plant foods contain only nonheme iron. ODS says the iron requirement is 1.8 times higher for vegetarians, and that vitamin C with a meal helps absorption while phytate in grains and beans reduces it. Our iron foods guide covers this.
• Zinc: ODS says phytates in legumes and whole grains bind zinc, and that soaking beans, grains and seeds in water for several hours before cooking can make more of it available. See zinc in foods.
• Iodine: ODS says vegans may not get enough, because seafood, dairy and eggs are major sources and most fruits and vegetables are poor ones. Almost all salt in US processed foods is noniodized, so the label tells you whether iodized salt was used. Our iodine guide and kelp guide cover the risks of too much from seaweed.
• Omega-3 fats: ODS says the body converts plant ALA into EPA and DHA only to a very limited extent, with reported rates below 15 percent. EPA and DHA are originally made by microalgae, and vegetarian supplements with algal oil exist. Our omega-3 guide explains the three types.

USDA data for foods that supply these nutrients

The table uses USDA FoodData Central SR Legacy values per common serving, with the percent of the FDA Daily Value. Compare the two soy beverages: fortification makes the difference for vitamin B12, vitamin D and calcium. SR Legacy lists no iodine values for these foods.

For plant omega-3, USDA SR Legacy lists about 5.1 grams of ALA in an ounce of dried chia seeds, about 2.6 grams in an ounce of walnuts and about 1.6 grams in a tablespoon of ground flaxseed, with no EPA or DHA in walnuts or flaxseed. Our guides to chia seeds, walnuts and flaxseed have the details.

Protein on a vegan diet

Beans, lentils, soy foods, seeds and whole grains all supply protein. The 2025 to 2030 Dietary Guidelines advise vegans and vegetarians to diversify plant protein sources for amino acid balance, which in everyday terms means eating a mix rather than relying on one food. Our guides to tofu, tempeh, lentils, chickpeas and edamame give USDA values for each, and our protein foods guide compares plant and animal sources. Soy and tree nuts are major food allergens, so people with those allergies need other options.

Processed vegan foods and label reading

Vegan does not automatically mean nutritious. The 2025 to 2030 Dietary Guidelines advise people to significantly limit highly processed vegan or vegetarian foods that can include added fats, sugars and salt. Plant-based burgers, vegan cheeses, sweetened plant beverages and snack foods vary widely, so the Nutrition Facts label is the place to compare sodium, added sugars and whether a product is fortified. Only fortified soy beverages count toward the dairy group in the 2020 to 2025 Dietary Guidelines; other plant beverages, such as almond, rice, oat or coconut, do not, because their overall nutrient content differs. Our soy milk guide compares them.

Who should get advice before going vegan

• Pregnancy and breastfeeding: the 2020 to 2025 Dietary Guidelines advise vegetarians and vegans in these life stages to ask a healthcare provider whether they need iron, vitamin B12, choline, zinc, iodine or EPA and DHA from supplements. ODS notes that exclusively breastfed infants of vegan mothers can develop vitamin B12 deficiency, which can cause neurological damage, failure to thrive, developmental delays and anemia if undetected.
• Infants and children: plan with a pediatrician or registered dietitian. The 2025 Academy paper covers adults only.
• Health conditions and medicines: anyone with a medical condition, a history of disordered eating or a long medicine list should talk with a clinician first.

Frequently Asked Questions

Questions about a label? Contact us or read our Buyer’s Guide. Food comes first; follow the label and ask a healthcare provider before starting a supplement, especially if you take medicines, are pregnant or have a food allergy. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Last reviewed October 2026.

Related guides: Vegetarian Diet: Types, Nutrients and the Healthy Pattern, B12 Foods: Animal, Fortified and Vegan Sources Ranked, High Protein Foods: USDA Values for Meat, Dairy and Plant Sources, Plant-Based Protein Sources: USDA Protein per Serving.