Evidence-based guide to thriving on a plant-based diet while supporting animal welfare
The scientific consensus on vegan nutrition is well-established: well-planned vegan diets can support health at every stage of life. However, "well-planned" is a meaningful qualifier. Vegan diets require attention to specific nutrients that are scarce or absent in plant foods, and individual variation in absorption and metabolism means that one-size-fits-all advice is insufficient. This guide synthesizes the current evidence to help people thrive on plant-based diets — for their health and for the animals.
No reliable plant source. Deficiency causes irreversible neurological damage. All vegans must supplement: 250mcg daily or 2500mcg weekly cyanocobalamin. Non-negotiable. Test annually.
ALA from flax/chia/hemp converts poorly to DHA/EPA. Algae-based DHA+EPA supplements bypass this. Critical for brain, eye, and cardiovascular health. 250-500mg DHA+EPA daily recommended.
Deficiency widespread in all dietary patterns in northern latitudes. D3 from lichen is vegan; D2 also available. 1000-2000 IU daily, more in winter or with low sun exposure. Test levels annually.
Dairy and seafood are main dietary sources; vegans often deficient unless using iodized salt or kelp supplements. Critical for thyroid function. 150mcg/day; kelp supplements vary widely — iodized salt more reliable.
1000mg/day achievable from fortified plant milks, tofu (calcium-set), leafy greens, almonds. Absorption from plant sources comparable to dairy when oxalates low. Avoid spinach-reliant approach (high oxalate).
Non-heme iron (plant) less bioavailable than heme iron. Consume with vitamin C; avoid tea/coffee with meals. Legumes, seeds, fortified cereals are good sources. Test ferritin; supplement if deficient.
Phytates in grains/legumes reduce absorption. Soaking, sprouting, and fermenting reduce phytate content. Pumpkin seeds, hemp seeds, legumes, fortified foods. May need 50% more than RDA.
Complete protein easily achieved combining legumes with grains (need not be at same meal). 0.8-1.1g/kg/day for most adults. Athletes: 1.6-1.8g/kg. Soy, lentils, quinoa, hemp excellent sources.