Supplements for vegetarians

The vegetarian stack — rationale by ingredient

Vitamin B12 250–1,000 mcg/day (or 1,000 mcg twice weekly)

The most important supplement for the lacto-ovo vegetarian. Even with regular egg and dairy intake, serum B12 declines over years compared with omnivores. Cyanocobalamin is cheap, stable, and effective for routine supplementation. Methylcobalamin is reasonable but more expensive. Skip the spirulina/chlorella "B12" claim — those are pseudo-B12 analogs that don't replete biochemistry.

Iron — only if ferritin is low

Plant-source iron (non-heme) is less bioavailable than heme iron from meat, and is further inhibited by phytates, tannins, and calcium. Menstruating women are the highest-risk subgroup. Test ferritin and CBC before supplementing; iron overload is real. Ferrous bisglycinate is better tolerated than ferrous sulfate. Take with vitamin C; separate from calcium and tea/coffee.

Algal oil 250–500 mg/day combined EPA+DHA

Plant-based diets are typically high in ALA (flax, walnuts, chia) but conversion of ALA to EPA is roughly 5% and to DHA much lower. Algal-derived DHA/EPA delivers the long-chain forms directly. Particularly important during pregnancy/lactation when DHA needs spike. Pescatarians eating 2+ servings of oily fish weekly may not need this; lacto-ovo vegetarians benefit.

Zinc 8–15 mg/day if dietary intake is low

Phytate-rich plant diets reduce zinc absorption. Vegetarian-specific dietary reference intakes are roughly 1.5× the omnivore RDA to compensate. Supplemental zinc at the RDA-equivalent dose is reasonable if dietary intake is questionable. Don't chronically exceed 40 mg/day — causes copper deficiency.

Creatine 3–5 g/day

Vegetarians have lower muscle creatine stores than omnivores at baseline. Trials show vegetarians get larger gains from supplementation than omnivores on strength, lean mass, and cognitive measures. Creatine monohydrate is the trial-tested form — synthetic, made by chemical synthesis (not animal-derived), suitable for vegetarians and vegans.

Vegan D3 from lichen 1,000–2,000 IU/day

Lichen-derived cholecalciferol (D3) is more effective at raising 25-OH-D than ergocalciferol (D2) and is now widely available in vegan formulations. Test 25-OH-D and target 30–50 ng/mL. Take with fat-containing meal.

Choline 250–500 mg/day if not regularly eating eggs

Eggs are the main dietary source of choline; lacto-ovo vegetarians who eat eggs regularly typically meet adequate intake. Pure plant-based eaters and lacto-only vegetarians may not. Choline matters for liver fat metabolism and neural function. Supplemental choline bitartrate or sunflower-derived phosphatidylcholine works.

Iodine 150 mcg/day if not using iodized salt

Without seafood or iodized salt, iodine intake can be marginal in vegetarians. Important for thyroid function and especially during pregnancy. Iodized salt is the easiest source; a 150 mcg potassium iodide supplement works if you avoid salt. Don't take high-dose kelp (variable iodine content, hyperthyroidism risk).