One common concern about vegan diets is whether they provide your body with all the vitamins and minerals it needs.
Many claim that a whole-food, plant-based diet easily meets all the daily nutrient requirements.
Some even encourage vegans to avoid all supplements.
Despite meaning well, this type of advice can do more harm than good.
Here are 7 nutrients that you may need to supplement with while on a vegan diet.
1. Vitamin B12
Foods often touted as rich in vitamin B12 include unwashed organic produce, mushrooms grown in B12-rich soils, nori, spirulina, chlorella and nutritional yeast.
Some believe vegans who eat enough of the right plant foods don’t need to worry about a vitamin B12 deficiency.
However, there is no scientific basis for this belief.
Several studies show that while anyone can have low vitamin B12 levels, vegetarians and vegans have a higher risk of deficiency. This seems especially true for vegans who are not taking any supplements (1, 2, 3).
Vitamin B12 is important for many bodily processes, including protein metabolism and the formation of oxygen-transporting red blood cells. It also plays a crucial role in the health of your nervous system (4).
The daily recommended intake is 2.4 mcg per day for adults, 2.6 mcg per day during pregnancy and 2.8 mcg per day while breastfeeding (4).
The only scientifically proven way for vegans to reach these levels is by consuming B12-fortified foods or taking a vitamin B12 supplement. B12-fortified foods commonly include plant milks, soy products, breakfast cereals and nutritional yeast.
What’s more, no scientific evidence supports depending on unwashed organic produce as a reliable source of vitamin B12.
Nutritional yeast only contains vitamin B12 when fortified. However, vitamin B12 is light-sensitive and may degrade if bought from or stored in clear plastic bags (14).
It’s important to keep in mind that vitamin B12 is best absorbed in small doses. Thus, the less frequently you ingest vitamin B12, the more you need to take.
This is why vegans who are unable to reach the recommended daily intake using fortified foods should opt for a daily supplement providing 25–100 mcg of cyanocobalamin or a weekly dosage of 2,000 mcg.
Those weary of taking supplements may find it reassuring to get their blood vitamin B12 levels checked before taking any.
But be aware that high intakes of seaweed, folic acid or vitamin B6 can falsely inflate markers of vitamin B12. For this reason, you may want to have your healthcare practitioner evaluate your methylmalonic acid status instead (15).
Interestingly, your ability to absorb vitamin B12 decreases with age. Therefore, the Institute of Medicine recommends that everyone over the age of 51 — vegan or not — consider fortified foods or a vitamin B12 supplement (16).
Bottom Line: It’s extremely important that all vegans get enough vitamin B12. The only reliable way to achieve this is by eating fortified foods or taking a vitamin B12 supplement.
2. Vitamin D
The RDA for vitamin D for children and adults is 600 IU (15 mcg) per day. The elderly, as well as pregnant or lactating women, should aim for 800 IU (20 mcg) per day (22).
That said, there is some evidence that your daily requirements are actually far greater than the current RDA (23).
Unfortunately, very few foods naturally contain vitamin D, and foods fortified with vitamin D are often considered insufficient to satisfy the daily requirements.
Besides the small amount you get from your diet, vitamin D can also be made from sun exposure. Most people likely make enough vitamin D by spending 15 minutes in the midday sun when the sun is strong — as long as you don’t use any sunscreen.
Furthermore, because of the known negative effects of excess UV radiation, many dermatologists warn against using sun exposure to boost vitamin D levels (28).
The best way vegans can ensure they’re getting enough vitamin D is to have their blood levels tested. Those unable to get enough from fortified foods and sunshine should consider taking a daily vitamin D2 or vegan vitamin D3 supplement.
Bottom Line: Vitamin D deficiency is a problem among vegans and omnivores alike. Vegans unable to maintain normal blood levels through fortified foods and sun exposure should consider taking a supplement.
3. Long-Chain Omega-3s
Omega-3 fatty acids can be split into two categories:
- Essential omega-3 fatty acids: Alpha-linolenic acid (ALA) is the only essential omega-3 fatty acid, meaning you can only get it from your diet.
- Long-chain omega-3 fatty acids: This category includes eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). They are not technically considered essential because your body can make them from ALA.
Long-chain omega-3 fatty acids play a structural role in your brain and eyes. Adequate dietary levels also seem important for brain development and preventing inflammation, depression, breast cancer and ADHD (31, 32, 33, 34, 35, 36).
Getting enough ALA should theoretically maintain adequate EPA and DHA levels. However, studies report that the conversion of ALA to EPA may be as low as 5%, whereas conversion to DHA may be near 0% (37, 38).
Additionally, research consistently shows that vegetarians and vegans have up to 50% lower blood and tissue concentrations of EPA and DHA than omnivores (39).
While no official RDA exists, most health professionals agree that 200–300 mg of a supplement containing EPA and DHA per day should be sufficient (39).
Vegans can reach this recommended intake through an algae oil supplement.
Minimizing your intake of omega-6 fatty acids from oils such as corn, soy, safflower, sunflower and sesame, as well as making sure to eat enough ALA-rich foods, may further help maximize EPA and DHA levels (40).