The Real Supplement Gaps for Vegans and Vegetarians

A well-planned plant-based diet is one of the healthiest ways to eat. But "well-planned" is doing real work in that sentence, because cutting out animal foods removes a few nutrients that are hard to get anywhere else. The goal is not to fear your diet or to buy a cabinet full of pills. It is to know the short, specific list of gaps a plant diet creates, and to fill exactly those.

Most of what vegans and vegetarians are told to supplement is unnecessary. A handful of nutrients, though, are genuinely worth your attention, and one of them is non-negotiable. Here is the honest list, ranked roughly by how much it matters, so you can supplement smart instead of supplementing everything.

Vitamin B12: the one you cannot skip

If you take nothing else, take this. Vitamin B12 is made by bacteria, not plants, so there is no reliable plant food that contains it. Not spirulina, not most mushrooms, not "fortified" claims you cannot verify. A true vegan diet contains essentially no B12 unless it is added.

This matters because B12 deficiency develops slowly and quietly over years, then causes fatigue, nerve damage, and cognitive problems that can become permanent. The fix is trivially easy: a regular B12 supplement (cyanocobalamin is cheap and effective; methylcobalamin is an alternative) or reliably fortified foods, ideally backed by an occasional blood test. Vegetarians who eat dairy and eggs get some B12 but are still often low, so it is smart insurance for them too. This is the single most important supplement on the list.

Omega-3: get EPA and DHA from algae

Plant foods do contain an omega-3 called ALA (in flax, chia, and walnuts), but your body converts only a small percentage of it into the forms that actually do the work, EPA and DHA. So a plant diet can look adequate on paper while running low on the active omega-3s.

The elegant solution is algal oil: an omega-3 supplement made from algae, the same place fish get their EPA and DHA in the first place. It delivers the active forms directly, with no fish involved. Keep eating your flax and walnuts, but if you want reliable EPA and DHA, an algae-based supplement is the clean vegan answer.

Vitamin D: check your source

Vitamin D is not strictly a vegan issue, most people who live indoors or far from the equator run low regardless of diet, but there is a plant-based wrinkle. The more effective form, D3, is traditionally derived from lanolin (sheep's wool), which is not vegan. Look for D3 from lichen, which is vegan and works as well as the animal-derived version; vitamin D2 is plant-based but generally less effective at raising blood levels. Take it with a meal that has some fat, since it is fat-soluble, as covered in our bioavailability guide.

Iron: absorbable, with attention

Plant (non-heme) iron is absorbed less efficiently than the heme iron in meat, so vegetarians need more of it and have to be a bit strategic. The two habits that matter: pair iron-rich plant foods (lentils, beans, tofu, spinach, fortified grains) with a source of vitamin C to boost absorption, and keep iron away from coffee, tea, and calcium at the same meal, which block it.

One caution: do not reflexively megadose iron. Excess iron is genuinely harmful and easy to overshoot, so supplement based on a blood test showing you need it, not on the assumption that "vegans need iron." Many plant-based eaters maintain perfectly good iron with food alone.

Zinc, iodine, and calcium: diet-dependent

These three depend on what your plant diet actually looks like.

• Zinc: plant zinc (from legumes, nuts, seeds, whole grains) is partly blocked by phytates, so needs run a little higher. Soaking, sprouting, and fermenting improve absorption. A modest supplement helps if your intake is low, but stay well under the upper limit, since too much zinc lowers copper.
• Iodine: without dairy or seafood, iodine can fall short. Iodized salt covers most people; sea vegetables work too but can swing wildly in content, so do not rely on large amounts of kelp, which can overshoot.
• Calcium: a non-issue if you use fortified plant milks and eat calcium-rich greens and tofu; worth supplementing only if your diet is genuinely low.

Creatine, and the lesser-known ones

Creatine is the best optional add-on for plant-based eaters. It comes almost entirely from meat and fish, so vegetarians and vegans start with lower muscle stores, and research suggests they may get a bigger benefit when they supplement, for both physical performance and possibly cognition. Standard creatine monohydrate is synthetic and fully vegan. It is not essential, but it is cheap, safe, and exceptionally well studied.

A few other compounds (taurine, carnosine, and choline) tend to run lower on plant diets. Most people do not need to supplement them, but choline is worth getting from sources like soy, and is a reasonable addition for those who eat few of them.

A sensible plant-based stack

That is the whole list. Plant-based eating does not require a pharmacy, just a short, deliberate set of fill-ins, with B12 at the top. Get those right and the diet does the rest.

Frequently asked questions

What supplements do vegans actually need?

The non-negotiable one is vitamin B12, which is not reliably available from plants. Strongly recommended for most are an algae-based omega-3 (EPA and DHA) and vitamin D if sun exposure is limited. After that it depends on your diet: iron, zinc, iodine, and calcium are worth checking, and creatine is a useful optional add-on. A well-planned plant-based diet covers the rest.

Can you get enough B12 without animal products?

Not reliably. B12 is made by bacteria, not plants, so there is no dependable plant food source; fortified foods and supplements are the safe route for vegans and smart insurance for vegetarians. B12 deficiency develops slowly and can cause permanent nerve damage, so this is the one supplement no vegan should skip, ideally with periodic blood testing.

Do vegans need an omega-3 supplement?

Often, yes. Plant foods like flax and walnuts provide ALA, but the body converts only a small percentage into the active forms EPA and DHA. An algae-based oil supplies EPA and DHA directly from the same source fish get them from, making it the ideal vegan option and the most reliable way to cover the omega-3s a plant diet tends to run short on.

Is plant-based iron enough?

It can be, but it takes attention. Plant (non-heme) iron is absorbed less efficiently, so vegetarians need more and should pair iron-rich foods with vitamin C while keeping them away from coffee, tea, and calcium at the same meal. Do not blindly megadose iron, though, since it is harmful in excess; supplement based on testing rather than assumption.

Should vegetarians take creatine?

It is a worthwhile optional add-on. Creatine comes mainly from meat and fish, so vegetarians and vegans start with lower muscle stores and may see a bigger response, including possible cognitive benefits, when they supplement. Standard creatine monohydrate is synthetic and vegan-friendly. It is not essential, but it is one of the best-evidenced and cheapest optional supplements for plant-based eaters.