Well-planned vegan diets can support health at every stage of life, from infancy through older adulthood. The Academy of Nutrition and Dietetics, Dietitians of Canada, and other major nutrition bodies affirm this. But "well-planned" is the key phrase — a few nutrients require specific attention to avoid deficiency. This guide covers what vegans need to know, based on current nutritional science.
Large-scale prospective studies including the EPIC-Oxford cohort, the Adventist Health Study 2, and the UK Biobank have consistently found that well-nourished vegans have:
These benefits depend on dietary quality — a vegan diet of processed foods and refined carbohydrates does not confer these benefits.
B12 is not reliably available from plant foods. Deficiency causes neurological damage that can be irreversible. Every vegan must supplement. Recommended: cyanocobalamin (most stable), 50-100mcg daily or 2000mcg 2-3x/week (sublingual or tablet). Get B12 levels tested regularly.
Sources: Supplements; fortified foods (plant milks, nutritional yeast, some cereals — but supplementation is more reliable than relying on fortified foods)
Many vegans are iodine deficient. Iodine is critical for thyroid function and fetal brain development. Ocean fish and dairy (from iodine-supplemented feeds) are major sources in omnivore diets; vegans must supplement. Supplement with kelp tablets OR iodized salt OR a dedicated supplement (150mcg/day). Note: some seaweeds have variable/excessive iodine — kelp nori and dulse are safer choices.
Plant foods provide ALA (flaxseed, walnuts, chia, hemp), but conversion to EPA and DHA (the omega-3s with strongest evidence for brain and cardiovascular health) is inefficient. Algae-based omega-3 supplements provide EPA/DHA directly from the original marine source (fish get their omega-3s from algae anyway). Recommended: algal oil supplement providing 200-300mg DHA/EPA daily.
Dairy is the most concentrated source in omnivore diets, but calcium is well-absorbed from fortified plant milks, tofu made with calcium sulfate, leafy greens (kale, bok choy — but NOT spinach), almonds, and fortified orange juice. Aim for 1000mg/day (1200mg over 50). Vitamin D is needed for calcium absorption.
Most people (not just vegans) are D-deficient in northern latitudes. Vegans may need to check that supplements are D3 (cholecalciferol) — some D3 is lanolin-derived (not vegan); lichen-derived D3 is vegan. Alternatively, D2 (ergocalciferol) is reliably vegan. Target 600-2000 IU/day depending on sun exposure.
Plant iron (non-haem) is less bioavailable than haem iron from meat. Vegans typically consume adequate total iron but need to maximize absorption: eat iron-rich foods (legumes, tofu, fortified cereals, leafy greens) with vitamin C; avoid coffee/tea with meals. Get ferritin tested periodically, especially women of reproductive age.
Plant foods contain zinc but also phytates that inhibit absorption. Sprouting, fermenting, and soaking legumes reduces phytates. Zinc needs may be 50% higher on vegan diets. Foods: legumes, tofu, tempeh, seeds, nuts, whole grains.
Protein adequacy is achievable on a varied vegan diet. The key is variety: legumes are high in lysine (limiting in grains); grains are high in methionine. Eating varied protein sources across the day (not necessarily at every meal) ensures amino acid adequacy. Protein needs: ~0.8-1.0g/kg body weight for adults; higher for athletes and older adults.