Many claim that a plant-based, whole-food diet meets all the requirements of daily nutrients. Some are even encouraging vegans to avoid all supplements. This advice can do more harm than good. Here are supplements you might need if you are on a vegan diet.
Vitamin D Supplements
Vitamin D is a fat-soluble vitamin that helps boost calcium and phosphorus absorption in your intestines. VD also stimulates many other processes of the body, including immune function, mood, memory, and regeneration of muscles (1, 2, 3).
In children and adults, the RDA is 600 IU (15mcg) per day. The elderly should aim for 800 IU (20 mcg) per day. That said, there is some evidence that your daily needs are much higher than the current RDA (4, 5).
However, very few foods contain vitamin D, and vitamin D foods are often inadequate to fulfill the daily requirements. These studies clarify worldwide records of vitamin D deficiency in vegetarian, vegans, and meat-eaters (6, 7).
Vitamin D can also be made from sun exposure besides the small amount you get from your diet. Most people are likely to make enough vitamin D when the sun is strong by spending 15 minutes in the midday sun as long as they don’t use any sunscreen.
People with darker skin, those who live in colder climates, and those who spend little time outdoors, may not produce enough. In fact, most dermatologists caution against using sun exposure to raise vitamin D levels due to the negative effects of excess UV radiation (8, 9, 10).
The best way for vegans to ensure they get enough vitamin D is to test their blood levels. Those who can not get enough from foods and sunshine should have a daily dose of D2 or vitamin D3. Although vitamin D2 is likely adequate for most people, some studies suggest that vitamin D3 appears to be more active in raising blood vitamin D levels (11, 12).
Foods that are often claimed to be rich in vitamin B12 include mushrooms, spirulina, Chlorella, and other organic products. Many claim that vegans consume enough of the right plant foods and they need not worry about vitamin B12 deficiency.
For this assumption, there is no scientific basis. Several studies show that vegetarians and vegans are at a higher risk of B12 deficiency. Vitamin B12 is essential for many processes in the body, including the metabolism of proteins and the production of red blood cells that carry oxygen. It also plays a key role in your nervous system’s health (15).
Insufficient vitamin B12 can cause anemia, infertility, bone disease, heart disease and damage to the nervous system. The recommended daily intake for adults is 2.4 mcg/day, 2.6 mcg/day during pregnancy and 2.8 mcg/day during breastfeeding (16, 17).
The only proven way vegans can achieve these levels is to eat B12-fortified foods or take a supplement of vitamin B12. B12-fortified foods often include vegetable milk, soy products, cereals for breakfast and nutritional yeast. Some plant foods appear to contain vitamin B12, but there is still discussion about whether this form is active in humans (19, 20, 21, 22).
However, as a reliable source of vitamin B12, no scientific evidence supports relying on organic products that are unwashed. However, if purchased from or stored in clear plastic bags, because vitamin B12 is light-sensitive and may degrade.
It is important to remember that your body absorb B12 in small doses. The less vitamin B12 you consume, the better your body absorbs it. That is why vegans unable to meet the recommended daily intake using fortified foods should opt for a daily supplement this offers 25–100 mcg of cyanocobalamin or 2,000 mcg weekly intake.
Keep In Mind
Those who are wary of taking supplements can find it reassuring to test their blood before taking any. But know that high intakes of seaweed, folic acid, can inflate vitamin B12 markers. Instead of your methylmalonic acid status, you may want your health care practitioner to test it.
B12 absorption decreases with age because of the lack of hydrochloric acid in the stomach. Therefore, the Institute of Medicine recommends B12-fortified foods or a vitamin B12 supplement for everyone over the age of 51 vegetarian or not (25).
Zinc is a mineral crucial to metabolism, immune function, and cell repair. Insufficient zinc intake can lead to problems with growth, hair loss, diarrhea, and delayed wound healing. Zinc RDA for adults is 8 to 9 mg per day. For pregnant women, it increases to 11–12 mg and for lactating women, 12–13 mg (26).
In addition, few plant foods contain zinc because of their phytate content, it reduces the absorption of zinc from some plant foods. Vegetarians are therefore advised to reach 1.5 times the RDA (54). Although a recent review of 26 studies showed that vegetarians and vegans have lower levels of zinc than meat-eaters (27).
Eat a variety of zinc-rich foods throughout the day to optimize your intake. These include whole grains, tofu, bread sprout, legumes, nuts, and seeds. Soaking nuts, seeds and legumes overnight also seems to improve absorption by eating enough protein and consuming fermented foods such as tempeh and miso (28).
Vegans concerned about their consumption of zinc or those with deficiency symptoms may consider taking a daily supplement of zinc gluconate or zinc citrate that provides 50% to 100% of the RDA.
Iron is a mineral used in the production of new DNA and red blood cells and in holding oxygen in the blood. It is also essential for the metabolism of energy (29).
Insufficient iron can cause anemia, and other symptoms, including fatigue and decreased immune function. Among adult men and postmenopausal women, the RDA is 8 mg. For adult women, it increases to 18 mg daily, and pregnant women will target 27 mg daily (30).
There are two ways to find iron: heme and non-heme. Heme iron is available only from products of animals, whereas non-heme iron is present in plants. Because heme iron is easier to absorb than non-heme iron in your diet, vegans are often recommended to target 1.8 times the normal RDA. That said, to decide whether you need such large intakes, we need further studies (31, 32).
Vegans with low levels of iron should target consuming more iron-rich foods such as cruciferous vegetables, beans, peas, dried fruit, nuts, and seeds. Iron-fortified foods such as cereals, enriched bread, and some plant milk can provide additional help (33, 34).
Use cast-iron pots and pans for cooking and baking. Also, avoid drinking tea or coffee with meals and mixing iron-rich foods with a vitamin C source can also help boost iron absorption. The best way to determine whether you need the supplement is to get your health practitioner to test your levels of hemoglobin and ferritin.
Keep in mind, excess intakes of supplements such as iron can do more harm than good. Top levels may even lead to seizures, organ failure, and sometimes may be fatal. Therefore, it is better not to supplement unless you really need it (35, 36).
Calcium is an essential mineral for bone and teeth health. It also plays a role in the control of the muscles, nerve impulses, and heart health. For most adults, they set the calcium RDA at 1,000 mg daily and increases to 1,200 mg daily in adults over 50 years of age (37).
Bok choy, kale, mustard greens, turnip greens, watercress, broccoli, chickpeas, calcium-set tofu, and fortified plant milk or juices are among the calcium sources. Studies agree, however, that most vegans do not get adequate calcium (38, 39).
An often-heard comment among the vegan community is that vegans have lower calcium needs than meat-eaters because they do not use this mineral to neutralize the acidity that a meat-rich diet produces.
For determining how meatless diets impact daily calcium requirements, we need further work. There is evidence, however, that vegans consuming less than 525 mg of calcium are at increased risk of bone fractures (40).
That’s why all vegans are encouraged to target the RDA, making sure they consume at least 525 mg daily. You should use supplements if the diet or fortified food alone can not do it.
Omega-3 fatty acids are classified into two categories:
Essential omega-3 fatty acids: alpha-linolenic acid (ALA) is the only essential omega-3 fatty acid, so you can get it only from your diet.
Long-chain omega-3 fatty acids: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are included in this category. They are not essential because your body can make them from ALA.
Long-chain omega-3 fatty acids play a crucial role in your brain and eyes. Adequate dietary levels also appear essential for brain function and to prevent obesity, anxiety, breast cancer and ADHD (41, 42, 43, 44).
Plants with a high content of ALA include flaxseeds, chia seeds, walnuts, seeds of hemp and soy. In animal products such as fatty fish and fish oil, EPA and DHA are mostly found.
Theoretically, having enough ALA will maintain adequate levels of EPA and DHA. Studies, however, show that ALA’s conversion to EPA may be as low as 5 percent, while DHA conversion may be close to 0 percent (45, 46).
Research also shows that vegetarians and vegans have up to 50 percent lower rates of EPA and DHA than meat-eaters. While there is no official RDA, most health professionals agree that there should be sufficient 200–300 mg of an EPA and DHA supplement per day (47, 48).
Vegans can use an algae oil supplement to meet this recommended intake. Minimizing your intake of omega-6 fatty acids from oils such as corn, soy, sunflower and sesame and ensuring that you eat enough ALA-rich foods can also help maximize the levels of EPA and DHA (49).
It is important to get enough iodine for good thyroid function, which regulates your metabolism. During pregnancy and early childhood, an iodine deficiency can lead to permanent mental retardation (50).
Insufficient intake of iodine in adults may cause hypothyroidism. This can cause symptoms such as low energy, dry skin, hand and foot tingling, fatigue, and weight gain. Vegans are at risk of iodine deficiency. Studies show that vegans have up to 50% lower levels of blood iodine than vegetarians (51, 52, 53).
The RDA is 150 mcg of iodine per day for adults. Pregnant women will strive for 220 mcg daily. Experts recommend it that breastfeeding woman’s intake should be 290 mcg daily (54).
Iodine levels depend on the soil’s iodine content in plant foods. The food is grown near the ocean, for example, is higher in iodine. Half a teaspoon of iodized salt (2.5 ml) is enough to meet your everyday needs. Vegans who do not want to eat iodine salt should iodine supplements.
The Bottom Line
Vegan diets for all stages of life should meet nutritional needs. That said, it may be difficult to achieve those nutrient requirements by diet alone and fortified foods. Those vegans unable to comply with their dietary recommendations by diet alone should take supplements. Also, before starting a new vitamin program, it’s best to talk to your healthcare provider.