The Best Supplements for Vegetarians and Vegans

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Plant-based diets carry real health upsides but also create predictable nutritional gaps. A handful of nutrients are either absent from plants, present in poorly absorbed forms, or only available in amounts no realistic diet provides. These are the supplements with the strongest case — and the doses that match the evidence.

Vitamin B12: Non-Negotiable for Vegans

Vitamin B12 is made only by microbes and reaches us through animal foods. Vegans who do not supplement will become deficient over time, and prolonged B12 deficiency can cause irreversible nerve damage. Either methylcobalamin or cyanocobalamin works for maintenance — head-to-head studies show similar results when adequate doses are used. Two practical regimens have strong evidence: 50–100 mcg daily, or 1,000–2,000 mcg twice weekly. The high-dose weekly approach works because of passive diffusion (about 1% of any oral dose is absorbed regardless of intrinsic factor), so it is reliable even for older adults with reduced absorption.

Vitamin D3 and Omega-3 DHA/EPA

Most D3 supplements come from lanolin (sheep wool, not vegan). Vegan D3 from lichen is bioequivalent and widely available — target 1,000–2,000 IU daily, adjusted by bloodwork. Conversion of plant-based ALA to EPA and DHA is poor in humans: less than ~8% to EPA and under ~4% to DHA, with conversion to DHA often well below 1%. Algal oil supplements deliver DHA (and now usually EPA) directly. Roughly 200–300 mg of DHA per day from algal oil is a reasonable minimum for general health.

Iron, Zinc, Iodine, and Calcium

Non-heme iron from plants absorbs at 2–20%, versus 15–35% for heme iron from animal foods. Iron bisglycinate is gentler on the gut than ferrous sulfate at equivalent elemental doses. Phytates in legumes and grains reduce zinc absorption, so the NIH suggests vegetarians need roughly 50% more dietary zinc than omnivores. Vegans who avoid dairy and seafood are at real risk of iodine inadequacy — 150 mcg daily of potassium iodide (or kelp standardized to a known iodine content) is a reliable solution. Calcium citrate absorbs well at any meal and does not require stomach acid, making it preferable to calcium carbonate for older adults or anyone on acid-suppressing medication.

Two Worth Considering

Creatine and carnosine (or its precursor beta-alanine) are higher in omnivores than vegetarians and respond well to supplementation. Creatine monohydrate at 3–5 g/day raises muscle creatine stores in vegans more than in omnivores at baseline and improves performance and possibly cognition. Choline is also commonly under-consumed on plant-based diets — soybeans, quinoa, and supplements (250–500 mg/day) close the gap.