Do Vegans and Vegetarians Need Supplements?

  • 7 Minutes Read
  • Jul 11, 2017

Vegan and vegetarian diets have a well-deserved reputation for health, but omitting meat from your diet does create some potential nutrient deficits. Here's the scoop on what those problems might be and whether supplements make nutritional sense.

Do Vegans and Vegetarians Need Supplements?

By now, the health reputation of meatless diets is well known. Research supports the health benefits of plant-based diets. They're linked to reduced rates of chronic diseases as well as lower body weight, easier weight loss and better general health. But there's another side to the argument for giving up meat: strict vegan or vegetarian diets might lack certain nutrients found only, or predominantly, in animal-sourced foods. In which case supplements might be in order.

When it comes to supplements, there are two key issues for vegans and vegetarians:

  1. How strict is your diet and what nutrients might be lacking?
  2. Are the actual supplements free of animal-sourced ingredients?

Nutrients of Concern

The good news is that plant based diets are naturally loaded with many nutrients, from potassium and magnesium to B vitamins, vitamin C and vitamin A. And of course high fiber intake can be another benefit. In fact, many people eating standard meat-based diets, with few vegetables or fruits, can have poor intakes of many of these nutrients.

But strict plant-based diets can lack some nutrients, depending on which foods you avoid, and how often you consume other foods. Here are some nutrients of concern:

Vitamin B12

B12 occurs naturally only in animal-sourced foods. And it's absolutely critical for health, playing a role in everything from red blood cell formation to nerve and brain function to gene replication and bone and heart health.

Unfortunately there are plenty of vegan myths about alleged plant-based B12 sources, but these are unfounded claims that could get you into trouble. Nutritional yeast, tempeh, seaweed and other false B12 sources may be fine foods, but they do not contain active B12. Don't fool around with this nutrient.

Vegetarians who consume dairy and eggs are likely to consume sufficient B12, assuming those foods are eaten daily. Many vegan foods, such as soy milk and ready-to-eat cereals are fortified with B12, sourced from microorganisms like algae. So it's possible that someone on a strict vegan diet could consume a sufficient amount from food. But if you don't consume those fortified foods, you could be at risk for deficiency, in which case a vegan B12 supplement would be appropriate.

How much do you need? The recommended intake from natural food sources is 2.4 micrograms/day for an adult. According to, a daily supplement of 10 mcg would be adequate. If you choose to take a vegan multiple, be sure B12 is included on the label, with at least the recommended 2.4 mcg dose.


Both vegetarians and vegans need to be concerned about iron. Dairy foods are poor sources of iron, so unless vegetarians eat many eggs, their iron sources will be plant foods. Plant-based diets can be high iron, but the form of iron is less easily absorbed than from animal foods. High iron plant foods include legumes, whole grains and greens. Refined wheat foods like bread and flour are fortified with iron, so iron intake from diet may be perfectly adequate.

Do you need a supplement anyway? Maybe not. Older adults typically do not need extra iron, regardless of diet type. Children and women of childbearing age do need to maintain adequate iron intake. Women with heavy menstrual periods are especially at risk. If you know you are iron deficient, you may need to take a supplement, at least at first, to get iron levels back to normal. But if you are not iron deficient, you don't need to add extra just because you are eating a meatless diet. Iron in supplements is not derived from any animal product unless described otherwise.


Vegetarians who consume dairy foods may have excellent calcium intake. And vegans can benefit from the many plant foods that are good calcium sources. However, what looks like a good source on paper may not be a good source when it hits your digestive system. The form of calcium in greens, for example, is very poorly absorbed. Legumes and some nuts, like almonds and sesame seeds, are better sources. Fortified plant milks, tofu made with calcium and other fortified foods can supply significant calcium. But a supplement may be necessary if you consume fewer than 3 servings a day of high calcium foods.

It's hard to know if you're calcium deficient. Blood levels are tightly controlled by hormones, and if serum calcium falls, it's pulled out of bones. So the only way to know much about your calcium status is to have a bone scan. But most people do not get such scans until after age 60. Adults of all ages who avoid dairy or fortified foods should consider a supplement, perhaps 300-600 mg/day depending on intake of high calcium foods. You shouldn't just rely on pills for your calcium intake. High calcium plant foods have many other nutrients and health benefits. But a calcium supplement should be considered if your intake of dairy or fortified soy milk or legumes is poor or inconsistent. The calcium used in supplements typically is not from any animal sources, unless noted otherwise. Oyster shell is sometimes listed as a source, but that form is not superior to other calcium sources.

Vitamin D

Vitamin D and calcium go hand-in-hand. Vitamin D facilitates calcium absorption. It's made in skin cells exposed to UV rays from the sun, but many people around the world are turning out to have deficient or insufficient blood levels, possibly due to our indoor lifestyles, use of sunscreen and locations in far northern regions where sunlight is weaker.

Food sources are limited to certain fish, animal and fish livers and eggs. Dairy foods have been fortified with minimal amounts of vitamin D for decades, and most soy milks are also fortified. Do you need a supplement? You might be getting enough if you consume fortified foods, so it's best to have your blood levels tested first.

If you need a supplement, keep in mind most vitamin D on the shelves is D3, or cholecalciferol, which is derived from fish or even sheep wool(!). Ergocalciferol, or D2, can be derived from yeast or mushrooms. This would be an appropriate form of vitamin D for a vegan or vegetarian to take, although it may not raise blood levels so effectively. If you're buying vitamin D supplements, the form of D will be listed on the label.

Depending on your starting blood level, your physician or dietitian can advise on an appropriate dose. Be sure to take vitamin D supplements with a meal that includes some fat, as this is a fat soluble vitamin. Whichever form of D you take, re-testing blood levels several weeks after starting a supplement will tell you if it's an adequate dose.


This mineral is listed as a nutrient of concern by the Academy of Nutrition and Dietetics' position paper on vegetarian diets. It might be of more concern for vegan diets. Dairy foods and eggs have some zinc, but the best food sources are meat and fish, especially oysters.

Vegan food sources include legumes, soy foods, nuts and needs and whole grains. Zinc is typically added to fortified cereals. It would be possible to consume enough entirely from plant foods, as long as the vegan diet was well balanced, free of processed junk food and included soy foods.

Zinc in supplements comes in a variety of salt forms. If you take a multiple vitamin, be sure zinc is included up to the daily recommended intake of 11 mg for males and 8 mg for females. Smaller amounts may be acceptable if your diet also includes good food sources of zinc.

Omega-3 fats

Like vitamin D, omega-3 fats are a very popular supplement. And like vitamin D, most of the widely available supplements are derived from animal - fish -- sources. I've written recently about the issues of omega-3 supplements for vegans, and here's a brief summary of the dilemma: Omega-3 fatty acids are critical for health, especially the long chain EPA (20 carbon) and DHA (22 carbon) molecules. The 18-carbon ALA omega-3 must be converted to either EPA or DHA before it's metabolically effective. That conversion is not very efficient in humans, which is unfortunate because many plant foods are high in ALA, notably canola oil, flax and walnuts.

EPA and DHA are not found in any plant foods, so vegans and vegetarians must either trust that eating high ALA foods everyday is an adequate solution to their needs, or find a supplement that's not made using fish. Remember, it's not a matter of occasionally eating a handful of walnuts or sprinkling flax on your oatmeal once a week. You need adequate intake of high ALA foods every day.

A supplement is a reasonable solution, and fortunately plant-sourced supplements are increasingly available. The long chain DHA and EPA are derived from algae. Typically the DHA is higher, which is different from omega-3 that's sourced from fish. The most important point is to find a supplement that includes both of these important forms of omega-3.

Supplements that are mostly ALA are not very useful; you can get that from food. EPA and DHA are the ones you want. Many vegan supplements are just DHA, because that form is most readily derived from algae. EPA has been more problematic until recently, but you can now find reasonably balanced formulas with both of these in equivalent doses.

Most of the major brands that make omega-3 supplements now include vegan options. Whatever you buy, keep it refrigerated and take with food.


The Academy of Nutrition and Dietetics considers iodine to be a nutrient of concern for vegetarians and vegans. Seafood is a rich source, and iodized table salt provides significant amounts. Dairy foods contain some iodine. Vegans avoid dairy and seafood, and if you also do not add iodized salt to your food you could be deficient.

Plant foods grown on iodine-rich soil would be good sources, but it's impossible to tell the iodine content of your particular tomato or lettuce or potato because the plants can survive on varying levels of iodine. Some areas of the world are known to have iodine-poor soil, and local populations suffered from a variety of iodine deficiency diseases.

Seaweed can be a good source, and some vegans may include seaweed in their diet. Kelp is the highest in iodine. It's estimated that one sushi roll, wrapped in seaweed, has about 92 mcg of iodine, or about the amount in 1/4 tsp of iodized table salt.

But if you eat no seafood or dairy and avoid salt and don't eat seaweed, you could be iodine deficient. This fits the description of a vegan diet. However the most effective way to insure an adequate intake would be to use iodized salt, about 1/3 tsp daily, which would cover the requirement of 150 mcg of iodine. A separate iodine supplement should be unnecessary although some multiples may include it.

One More Thing

You might be concerned about the nutrients in the supplements, but what about the actual capsule itself? Yes vegans and vegetarians need to think about the capsules as well. Most are made using gelatin, derived from animals. Fortunately for vegans and vegetarians, capsules made from cellulose or other non-animal substances are widely available. Capsules would be an issue only for certain supplements, such as vitamin D and omega-3 fats.

How Do I Know It's Vegan?

Some organizations dedicated to vegan lifestyles have certification programs for all manner of animal-free products. Foods, supplements, shoes, handbags, lotions. You name it. For example, the Vegan Awareness Foundation, under the name Vegan Action, certifies products as vegan according to a list of standards that prohibits any animal-sourced ingredients. Keep in mind, companies pay for such certifications. If you're looking for a certified supplement, many manufacturers may not choose to pay these fees. Their products might be fine for vegans, but you won't find a little certification symbol. When looking for supplements, keep in mind all the tips above for picking animal-free supplements and you won't need to rely on certification stamps. Most nutrients are not derived from animal sources anyway. The ones that could be -- vitamin D and omega-3 fats - are available in vegan forms, and if you read through those sections above, you've got enough information to identify which products fit your needs.

Meal Planning & Diets->Vegetarian Nutrients->Supplements
Donna P Feldman MS RDN is author of "Feed Your Vegetarian Teen", writes about food and nutrition at Radio Nutrition and is co-host of the Walk Talk Nutrition podcast series.
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