A vegan diet is often questioned whether it provides the body with all the vitamins and minerals it needs.
Many people believe that a whole-foods plant-based diet easily meets their daily nutrient needs.
Some even advise vegetarians to do without any nutritional supplements. This form of advice can do more harm than good despite good intentions.
If you are on a vegan diet, you may need to supplement the following nutrients.
See also: How to be a healthy vegan
Unwashed organic vegetables, mushrooms that grow in B12-rich soil, nori, spirulina, chlorella, and nutritional yeast are popular sources of vitamin B12.
Some vegans believe that they won’t be vitamin B12 deficient if they eat right. However, this belief lacks any scientific basis.
While anyone can have low vitamin B12, some studies show that vegetarians and vegans are at higher risk for deficiency. This seems especially true for vegans who do not supplement their diets. (Reference 1, 2, 3)
Many biological activities depend on vitamin B12, including protein metabolism and the formation of oxygen-carrying red blood cells. It’s also necessary for maintaining a healthy nervous system.
Infertility, anemia, nervous system damage, and bone and heart problems can result from vitamin B12 deficiency. (Reference 4, 5, 6)
Adults should consume 2.4 micrograms per day, 2.6 micrograms per day during pregnancy, and 2.8 micrograms per day during lactation.
According to scientific findings, vegans can only achieve these levels by eating foods fortified with B12 or taking vitamin B12 supplements. Plant-based milk, soy products, breakfast cereals and nutritional yeast are B12-enriched foods.
In addition, there is no scientific evidence that unwashed organic vegetables are a reliable source of vitamin B12.
Only refined nutritional yeast contains vitamin B12. Vitamin B12, on the other hand, is light sensitive and can spoil if purchased or stored in clear plastic bags (Reference 14).
It is important to remember that vitamin B12 is best absorbed in small amounts. Therefore, the less vitamin B12 you consume, the more you need.
For this reason, vegans who cannot absorb enough cyanocobalamin from fortified foods should take a daily supplement containing 25-100 mcg of cyanocobalamin or a weekly dose of 2,000 mcg.
It may be reassuring for those hesitant to take supplements to have their vitamin B12 levels checked before taking supplements.
Finally, as we age, our ability to absorb vitamin B12 decreases. The Institute of Medicine advises anyone over 51, vegan or not, to take fortified meals or vitamin B12 supplements. (Reference 15)
Adequate vitamin B12 is critical for all vegans. The only way to obtain sufficient vitamin B12 is to eat fortified foods or take a vitamin B12 supplement.
2. Vitamin D
Vitamin D, a fat-soluble vitamin, helps absorb calcium and phosphorus from the stomach (Reference 16).
For children and adults, the recommended daily allowance (RDA) for vitamin D is 600 IU (15 mcg) per day. Elderly, pregnant, or lactating women should consume 800 IU (20 mcg) per day (Reference 21).
However, some data suggest that your daily requirement is significantly higher than the current RDA (Reference 22).
Unfortunately, there are few foods that naturally contain vitamin D, and fortified foods are often considered insufficient to meet daily needs.
Vitamin D can be made through sun exposure and a modest amount ingested through food. Most people get enough vitamin D by exposing themselves to sunlight for 15 minutes during midday hours unless they wear sunscreen and expose most of their skin.
However, older people, people with darker skin tones, people who live in northern latitudes or colder climates, and people who spend little time outdoors may not be able to produce enough (Reference 24, 25, 26, 27).
In addition, many physicians discourage sun exposure to increase vitamin D levels because too much UV radiation is known to have harmful consequences (Reference 28).
For vegans, it is best to have blood levels checked to ensure that they are consuming enough vitamin D. Those who do not get enough vitamin D from fortified meals or sunlight should take a vitamin D2 or vegan vitamin D3 supplement daily.
Although vitamin D2 is sufficient for most people, recent research suggests that vitamin D3 is more effective in raising blood vitamin D levels (Reference 29).
Vegans and omnivores can suffer from vitamin D deficiency. Vegans who cannot maintain adequate blood levels through a fortified diet or sun exposure may consider supplementation.
3. Long-chain Omega-3s
Omega-3 fatty acids are divided into two types:
The only necessary omega-3 fatty acid is alpha-linolenic acid (ALA), which we can only obtain from food.
The other one is Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), two long-chain omega-3 fatty acids (DHA). Since the body can produce them from ALA, they are not considered necessary.
Long chain omega-3 fatty acids play an important role in the brain and eyes. Adequate amounts in the diet appear to be vital for brain development and reduce the risk of inflammation, depression, breast cancer, and ADHD (attention deficit hyperactivity disorder) (Reference 30, 31, 32, 33, 34, 35).
Flaxseeds, walnuts, hemp seeds, chia seeds, and soybeans are high in ALA. Animal sources, such as fish oil and fatty fish, are high in EPA and DHA.
If you consume enough ALA, you should probably keep your EPA and DHA levels in check. However, studies suggest that the conversion of ALA to EPA is only 5-10%, while the conversion to DHA may be as low as 2-5%. (Reference 36, 37).
In addition, studies have repeatedly shown that vegetarians and vegans have up to 50% less EPA and DHA in their blood and tissues than omnivores (Reference 38).
Most physicians believe that 200-300 mg per day is sufficient (Reference 38).
Algae oil can help vegans get the right amount of omega-3 fatty acids.
In addition, limiting consumption of omega-6 fatty acids from oils such as corn, safflower, sunflower, and sesame oils while increasing consumption of foods rich in ALA may help achieve higher levels EPA and DHA (Reference 39).
Vegans have lower long-chain omega-3 fatty acids in their blood and tissues. Therefore, they may benefit from supplementation with EPA and DHA.
Iodine is essential for the optimal function of the thyroid gland, which regulates metabolism.
Iodine deficiency can cause permanent mental problems if it occurs during pregnancy or early childhood (Reference 40).
In adults, iodine deficiency can lead to hypothyroidism.
Low energy, dry skin, tingling in the hands and feet, forgetfulness, sadness, and weight gain are possible symptoms (Reference 40).
The RDA for iodine in humans is 150 mcg per day. Pregnant women should aim for a daily intake of 220 mcg, while lactating women should aim for a daily intake of 290 mcg (Reference 43).
The amount of iodine in plant foods depends on the amount of iodine in the soil in which they were grown. Thus, the iodine content is higher in foods grown near bodies of water.
Iodized salt, shellfish, seaweed, and dairy products that absorb iodine from cleaning solutions for cows and farm equipment are the only foods with high iodine content.
To meet the daily requirement, half a teaspoon (2.5 ml) of iodized salt is sufficient.
Vegans who do not want to eat seaweed or iodized salt weekly may consider taking an iodine supplement.
Iodine is required for normal thyroid and metabolic function. Vegans who do not get enough iodine from seaweed or iodized salt may benefit from taking an iodine supplement.
Iron is a nutrient that helps form new DNA and red blood cells and oxygen transport in the body. It is also needed for energy metabolism (Reference 44).
Anemia and symptoms such as fatigue and a weakened immune system can result from iron deficiency.
For adult men and postmenopausal women, the RDA is 8 mg. Adult women should take 18 mg daily, while pregnant women should take 27 mg daily (Reference 45).
Heme iron (found only in animal products) and non-heme iron (found in plants) are the two forms of iron. (Reference 44).
Because heme iron is more readily absorbed from food than non-heme iron, vegans are often recommended to consume 1.8 times the required daily intake. However, further research is needed to determine if such a high intake is necessary (Reference 46).
Vegans with low iron intake should consume iron-rich foods such as cruciferous vegetables, beans, peas, dried fruits, seeds, and nuts. Iron-fortified foods such as bread, cereals, and some plant milks may help even more (Reference 23, 47).
Cooking with cast-iron pots and pans, not drinking tea or coffee with meals, and mixing iron-fortified foods with vitamin C can also promote iron absorption.
It is best to have your hemoglobin and ferritin levels determined by a physician to determine if supplements are needed.
Supplements such as iron can do more harm than good by damaging cells or preventing the absorption of other nutrients (Reference 48).
Extremely high levels can lead to convulsions, organ failure, coma, and death in extreme cases. Therefore, dietary supplements should be taken only when necessary (Reference 49).
Vegans who are iron deficient should consider fortified foods or taking supplements. Iron supplements are not suitable for everyone, as excessively high levels can be dangerous.
Calcium is an important mineral for strong bones and teeth. It affects muscle function, nerve signaling, and heart health.
For most people, the RDA for calcium is 1,000 milligrams per day, and for those over 50, it is 1,200 milligrams per day (Reference 50).
Calcium-fortified plant milks and juices include bok choy, kale, mustard greens, kohlrabi, watercress, broccoli, chickpeas, calcium-rich tofu, and calcium-rich tofu.
Vegans have lower calcium needs than omnivores, it is commonly believed, because they do not utilize this mineral to compensate for the acidosis caused by a meat-rich diet.
Further research is needed to determine how a vegetarian diet affects daily calcium requirements. However, vegans who are consuming less than 525 mg of calcium have an increased risk of bone fractures (Reference 52).
Therefore, it is strongly recommended that all vegans consume at least 525 mg of calcium daily to meet the RDA. Vegans should take calcium supplements if they cannot get enough calcium from their diet or fortified foods.
Vegans who do not get enough calcium from their diet should consider taking a daily supplement. Especially those who consume less than 525 mg per day.
Zinc is an important mineral for metabolism, immune function and cell repair.
Insufficient zinc intake can lead to developmental disorders, hair loss, diarrhea and wound healing delays.
For adults, the RDA for zinc is now set at 8-11 mg per day. For pregnant women, it increases to 11-12 mg, and for lactating women, it increases to 12-13 mg (Reference 53).
Only a few plant foods contain zinc. In addition, zinc intake from several plant foods is reduced because of their high phytate content. As a result, vegetarians should aim for 1.5 times their RDA (Reference 53).
While not all vegans are deficient in zinc, a recent study found that vegetarians, especially vegans, have slightly lower zinc levels than omnivores (Reference 54).
Eat a variety of zinc-rich meals throughout the day to get the most out of your zinc intake. These include whole grains, wheat germ, tofu, sprouted bread, legumes, nuts, and seeds.
Vegans concerned about their zinc consumption or experiencing signs of zinc deficiency may consider taking a daily zinc gluconate or zinc citrate supplement containing 50-100% of the RDA.
Vegans who are not consuming enough zinc should start eating more foods containing zinc. Those who have low blood zinc levels should take a daily supplement.
A well-planned vegan diet can meet all your nutritional needs.
Certain nutritional needs may be difficult to meet through diet and fortified foods.
This is especially true for B12, D, and long-chain omega-3 fatty acids.
Vegans who cannot meet their nutritional needs through food alone can turn to supplements. However, consult your doctor before taking supplements.