When transitioning to a vegan diet, many people wonder if they need supplements, and if so, which ones?
Knowing how to meet nutrient needs through foods and supplements is important for anyone on a vegan or mostly plant-based diet. While vegan diets can be appropriate for all stages of life, they must be well planned to meet nutrient needs.
This article reviews important nutrients for vegan diets and whether supplements are needed, or not, for each.
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This article is for informational and educational purposes only. It is not prescriptive and individual needs vary.
Always speak with a doctor before changing your diet or taking new supplements. Please read our full website disclaimer.
What is a Vegan Diet?
A vegan diet is an eating pattern that eliminates all animal products including meat, poultry, fish, seafood, dairy, eggs and honey.
Instead, vegan diets focus on eating plant-based foods including:
- Legumes (beans, lentils, soy)
- Grains
- Vegetables
- Fruits
- Nuts and seeds
- Herbs and spices
There are many pre-made or packaged vegan food options as well.
Veganism is an ethical focus on reducing harm to animals. Those who follow a vegan diet are typically doing so for the benefit of animals.
Alternately, the term “plant-based diet” is frequently used but doesn’t have a clear definition. Those following a plant-based diet may include varying amounts of animal products in meals.
Anyone eating a mostly plant-based diet (with very little or no animal products) needs to be aware of how to meet nutrient needs from plant-based and vegan foods.
Which Nutrients do Vegan Diets Lack?
Talk about vegan diets often focuses on protein intake, but that’s often not a concern for most vegans. Instead, certain potentially lacking vitamins and minerals should be a priority.
There are also concerns with how plant-based foods affect absorption of some nutrients (the ability for people to digest and use nutrients).
Vegan diets can meet the nutrient needs of most people with one exception, vitamin B12, which must come from supplements or fortified foods.
Other nutrients, like vitamin D, omega-3s, iodine, calcium, iron and zinc may be tricky for some vegans to get through food alone, although it’s possible to do so.
There is some concern for other nutrients including vitamin A, selenium, protein and vitamin K, but many vegans do not require supplements for these nutrients.
Vitamin B12
Vitamin B12 is not present in plant-based foods, so it’s recommended that all vegans take a vitamin B12 supplement.
There are many claims about the presence of B12 in vegan foods but there’s not enough research to suggest these are “active” forms of vitamin B12.
Vitamin B12 intake recommendations for adults are 2.4 micrograms/ day according to the Institute of Medicine, and 4 micrograms/ day from the European Food Safety Authority.
The body can only absorb so much B12 at one time, so taking slightly larger amounts of B12 supplements is likely needed.
Vegan health experts generally recommend one of two options for B12 supplements, either 25-100 micrograms daily OR 1000 micrograms twice per week.
There are additional vitamin B12 supplement regimes reported elsewhere.
These recommendations are for cyanocobalamin supplements only.
Another type of B12 supplement, methylcobalamin is becoming very popular. There currently isn’t enough research to know what dosage of methylcobalamin is needed to meet vitamin B12 needs. Based on very limited information, it seems significantly higher amounts of methylcobalamin are required (than the standard cyanocobalamin).
Alternatively, vegans can eat 2 servings of foods fortified with B12 each day, with one serving offering 2-3.5 micrograms of vitamin B12. This can be challenging to achieve consistently, which is why supplements are typically recommended.
Vitamin D
Plant-based foods only contain small amounts of vitamin D unless they’re fortified. While the body can produce vitamin D when skin is exposed to sunlight, this is not a practical source for many reasons.
Vitamin D supplements are often recommended for people who don’t regularly consume fortified foods and/or get adequate sunlight exposure.
At high latitudes, during winter months, the suns rays are not adequate to produce vitamin D. Even if you get adequate sunlight in the summer, if you are at a high latitude, you must rely on fortified foods or supplements during winter.
Most health authorities recommend 600 IU of vitamin D per day, and this may be a good target amount for supplements. After age 70, recommendations typically increase to 800 IU per day.
There’s also an upper limit set for vitamin D at 4000 IU per day. Intake above this amount may be harmful and shouldn’t be taken without medical supervision (some supplements are at or above this amount, so caution is warranted).
Not all vitamin D supplements are vegan. Vitamin D2 is always vegan and should be adequate for most people; however, some evidence suggests vitamin D3 may be a better option. Unless specified, assume that vitamin D3 is not vegan.
Omega-3s: ALA, EPA and DHA
There are three types of omega-3s important for humans: ALA, EPA and DHA.
ALA is considered an essential nutrient. Some health experts believe DHA should also be considered essential, but it is not independently classified as an essential nutrient.
Adequate intake of ALA is thought to be 1.1 and 1.6 grams per day for women and men, respectively.
ALA is found in many vegan foods (walnuts, ground flaxseed, chia seeds, hemps seeds, soybeans, oils made from these foods and canola oil) and supplements aren’t likely needed if eating these foods regularly.
The body can technically convert ALA into EPA, then into DHA. However, research suggests many people do not convert much ALA into DHA.
Since there are valid arguments for humans needing DHA specifically, some vegan nutrition experts recommend vegans take a DHA supplement. There are no good sources of DHA specifically in vegan foods.
The European Food Safety Authority recommends adults consume 250 milligrams of DHA daily.
If taking a DHA supplement, people must still consume adequate ALA through foods.
Iodine
Iodine only presents adequate intake amounts in two vegan food options, seaweed and iodized salt.
The amount of iodine in seaweed is highly variable and is not considered a reliable source. Additionally, seaweed may contain levels of iodine that are too high (this may be a concern with regular consumption).
Iodized salt is a reliable source of iodine. Typically, ½ teaspoon of iodized salt per day should meet the needs of most non-pregnant adults.
However, with the rise of alternative salts (pink salt, sea salt) many vegans may not consume iodized salt. These alternative salts are not a source of iodine unless it specifies they’re iodized.
Some people are also concerned about salt/ sodium intake and would prefer to directly take an iodine supplement rather than using iodized salt.
Most health authorities recommend 150 micrograms of iodine per day for non-pregnant adults. A supplement that offers this amount may be a good target.
As with most nutrients, iodine intake has an upper limit of 1100 micrograms per day for adults. This includes intake from food and supplements combined; intakes above this amount are believed to cause harm.
Calcium
Calcium is one of the most challenging nutrients to consume in adequate amounts on a vegan diet, especially if you don’t regularly consume fortified foods.
There are some concerns with how well calcium is absorbed from plant-based foods due to a compound called oxalate. Oxalate is present in many plant-based foods and can severely limit the amount of calcium absorbed from a meal.
Vegans who struggle to consume high-calcium, low-oxalate foods (low-oxalate leafy greens, calcium-set tofu, fortified beverages or other fortified foods) throughout the day may benefit from a small calcium supplement. This supplement is intended to top up the calcium present in someone’s usual diet.
It’s not recommended to rely on a supplement to meet total daily calcium intake requirements.
It’s best to determine how much calcium you typically consume. If not meeting intake recommendations, see if it’s possible to add more high-calcium foods to your regular diet. If not, speak with a doctor or dietitian about a small calcium supplement (small typically means 300-500 milligrams).
The Institute of Medicine recommends adults consume 1000 milligrams of calcium per day. Females over 50 and men over 70 have increased recommendations of 1200 milligrams per day.
The upper limit for calcium intake in adults under age 50 is 2500 milligrams per day. This includes intake from food and supplements combined. Over age 50, the upper limit is 2000 milligrams per day.
Iron
Iron is present in plant-based foods, but absorption of plant-based iron may be a concern for vegans.
Adding vitamin C to a meal that contains iron is the best way to improve absorption of iron from plant-based foods.
Iron is found in legumes (beans, lentils, soy), nuts, seeds, grains (whole grain plus fortified refined grains) and some vegetables (in smaller amounts). Since one or more of these foods is typically in a vegan meal, it’s best to pair a source of vitamin C with most meals.
Iron supplements aren’t routinely recommended to vegans, but some people may need them. If low iron levels are a concern, blood testing may help determine the best course of action.
If low iron levels are detected, work with your doctor or a dietitian to raise and maintain optimal levels. If taking iron supplements, a healthcare professional should monitor your iron status.
Zinc
Zinc is found in smaller amounts in plant-based foods, and unfortunately, absorption of zinc from plant-based foods is also a concern.
Zinc is found in legumes (beans, lentils, peas), soy (including tofu and tempeh), seeds, nuts, whole grains and fortified foods. Sprouting, soaking and fermenting foods can improve zinc absorption.
While intake requirements for zinc can be met on a vegan diet, some good planning ensures adequate amounts are regularly consumed.
Zinc supplements aren’t routinely recommended to vegans unless intake is low or there is a medical condition that limits absorption.
Zinc recommendations vary based on the source. Some research suggests needing higher amounts in strict vegetarian (vegan) diets due to limited absorption.
Summarizing all the zinc intake recommendations leads to ranges of intakes of 9-16 milligrams per day for adult men and 7-12 milligrams per day for adult women.
The higher ends of these ranges factor in the lower absorption of zinc from plant-based foods.
There’s also an upper limit set for zinc of 40 milligrams per day for adults. Intakes at this level are unlikely to happen from food alone, but there are many zinc supplements with this amount or higher.
Other Nutrients (Protein, Selenium, Vitamin A, Vitamin K)
Protein needs can be met on a vegan diet if people regularly eat higher protein foods. Beans, lentils, soy (tofu, tempeh, edamame, soy milk, etc.) offer the most protein and are a good source of the amino acid lysine.
Smaller amounts of protein are found in whole grains, seeds and nuts. Vegetables can add small amounts of protein to the diet as well but shouldn’t be relied upon to meet protein intake needs.
Vegan diets don’t typically require protein supplements/ protein powders. However, these products can be a convenient option to add more protein to plant-based diets.
Selenium content in foods is dependent on the soil food was grown in. This nutrient shouldn’t be a concern for vegans as it’s found in legumes and whole grains which are often a staple of vegan meals. Brazil nuts have extremely high amounts of selenium; just 2-3 nuts per week can meet selenium needs for most adults.
Vitamin A is not present in vegan foods unless they’re fortified. However, beta-carotene is found in many plant-based options and the body converts beta carotene to vitamin A. Orange vegetables are the best source of beta carotene. Some orange fruits are also good sources.
Vitamin A supplements aren’t routinely recommended to vegans and there are concerns with excess intake of vitamin A causing toxicity.
Vitamin K hasn’t traditionally been a concern for vegan diets as it’s present in many vegetables, specifically green vegetables. However, newer research suggests there are two forms of vitamin K, K1 and K2, and these may have different roles in the body.
Vitamin K2 isn’t present in high amounts in vegan foods (other than natto, a fermented soy food commonly eaten in Japan). Some research suggests humans may need vitamin K2 separate from K1. This has led to some recommendations for vegans to consume a vitamin K2 supplement.
Summary: Supplements for a Vegan Diet
Vegan diets require a reliable source of vitamin B12 from supplements (or fortified foods consumed at least twice per day).
Vitamin D and omega-3s (specifically DHA) are often recommended for vegans to supplement as well.
Iodine is the final nutrient that vegans need to supplement unless regularly using iodized salt.
The other nutrients including calcium, iron, zinc, vitamin A and selenium may require supplementation depending on the individual and what foods their regular diet contains.
Some experts believe vegans would benefit from supplementing with vitamin K2 but more research on this nutrient is needed.
Most vegans do not need to use protein powders, but they can if they like.
Always speak to your doctor or primary care provider before starting new supplements.
References Cited
For fully referenced nutrition research, please see individual articles for each nutrient:
Always speak with a doctor before changing your diet or taking new supplements. Please read our full website disclaimer.
About Nicole Stevens
Nicole is a vegan Registered Dietitian (RD) and founder of Lettuce Veg Out.
She helps people thrive on a vegan diet with balanced recipes and easy-to-understand nutrition science.
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