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The 4 Supplements That Vegans Should Take

The first thing that should be mentioned is there can be great variation among vegan diets.

Some vegans may eat processed vegans foods that are fortified with many types of vitamins and minerals. Other vegans may eat no packaged or processed foods instead only eating natural whole foods.

Some vegans eat nuts and seeds. Others do not.

Some vegans eat seaweed, nori, kelp, kimchi. Others do not.

The common denominator, though, is that vegans do not eat meat or animal products like dairy, which includes cheese and cow milk.

Let's now go through the most common vegan needs in terms of vitamins and minerals.

Vitamin B12

Supplementing vitamin B12 is something that vegans universally need to do.

Vitamin B12 is found in foods of animal origin. It is not naturally present in plant foods. Therefore, supplementation becomes a must for long-term vegans who never consume animal products. This is especially true for vegans who don't eat any packaged foods or drinks, which sometimes come fortified with vitamin B12.

I, as the author of this article, a nurse practitioner, am a long-term vegan and I myself had to start supplementing vitamin B12 after my labs turned low for B12 years after beginning the diet. It is stated that vitamin B12 stores in the liver can last for 2 to 5 years before being completely exhausted. So after a person becomes vegans, it may take several years before all the B12 in his or her system runs out. But it will. And when it does, it can manifest as health problems such as nerve issues or megaloblastic anemia, since vitamin B12 is needed to create red blood cells.

Vegans can supplement this through oral tablets, as only people who lack intrinsic factor need IM injections.

Vitamin D

Vitamin D is something that vegans and non-vegans alike need to supplement due to the fact that so many people now work indoors and have limited sun exposure.

Even with exposure and plenty of outdoor activity can still produce deficiencies.

When in doubt, check your vitamin D level before supplementing to see where your baseline is.

If you are low, then you want to supplement.

Iodine

Another common vegan deficiency is iodine.

However, it depends.

Are you a vegan that incorporates seaweed, kelp, nori, kimchi into your diet? Do you add iodized salt to some of your food?

If so, you may be getting adequate iodine.

If not, you may need to supplement.

Vegan foods high in iodine include seaweed (nori, kelp).

Nonvegan foods high in iodine include seafood (cod, shrimp, tuna), dairy products (milk, yogurt, cheese), and eggs.

I, again a vegan, did a iodine urinary test, where a random sample of urine was checked for iodine composition corrected for the creatinine. Normally levels are 44-503 μg/L (as per Bioreference lab parameters). My level was 6 μg/L, showing clear deficiency. Normally iodine levels corrected for the amount of creatinine in the urine is 65-437 μg/g creatinine. My level was 4 μg/g creatinine. So there was a clear deficiency of iodine. Again, I am a vegan who eats no seaweed, nori, kelp, nimchi, or any sea vegetables. If you are the same, supplementation is necessary.

Selenium

Another common vegan deficiency is selenium.

Selenium actually goes along well with iodine, as it functions as a companion nutrient to iodine protecting the thyroid from oxidative stress and helping the process of converting T4 hormone to the more biologically active T3 hormone, which helps to control our metabolism.

Fruits and vegetables are generally not a high source of selenium.

Again, this need can vary in vegan diets, because there are vegans who eat nuts and seeds and there are others like myself who do not.

Brazil nuts tend to be a very high source of selenium. A brazil nut provides between 8-83 μg/g of selenium.

Another high source of selenium for vegans are sunflower seeds.

Nonvegan sources high in selenium include yellowfin tuna, halibut, sardines, shrimp, beef, turkey, chicken, and eggs. These foods help support thyroid health, immune function, and metabolism.

I, myself, as a vegan, did a serum selenium blood test and it came back low. According to Bioreference Labs parameters, normal levels are 63-160 μg/L and my result was 44 μg/L, showing deficiency.

I don't eat any nuts or seeds and to that point did not supplement selenium in any way. That is when I knew I had to supplement.

Other studies similarly show that vegans tend to have low selenium levels due to exclusion of animal products.

So the 4 supplements that vegans should take are vitamin B12, vitamin D, iodine, and selenium.

There have been studies that have stated that vegans can have low levels of calcium or low levels of ferritin.

However, I have run my own labs on these and have never had issues with low calcium or ferritin.

This could vary on an individual level and heavy mensturation can affect the iron levels of women, so there are gender differences as well. But the vegan diet, no matter which you follow whether fruitarian or any other, provides plenty of calcium and iron.

Vegans also get plenty of potassium and magnesium from their diets and do not need to supplement them.

By David Hylton, FNP-C

April 15, 2026