Vitamins and Supplements

7 Supplements To Ask Your Doctor About If You’re on a Plant-Based Diet

Colleen De Bellefonds

Photo: Getty Images / kate_sept2004
While many health experts emphasize that people should get their nutrients from food first, there are some eating plans where supplementation is crucial—particularly in vegan and plant-based eating. That’s because some nutrients that the body requires are not as readily available when you’re not eating animal products.

“I often hear that because plant-based diets require supplementation then they aren’t natural, but most diets could benefit from a boost of supplementation,” says Alex Caspero, RD, founder of Delish Knowledge, who specializes in plant-based diets. “Supplements aren’t a four-letter word!” To that end, she notes that even Americans who do eat meat get the majority of some nutrients from fortified foods (such as vitamins A and D in milk, folate in cereal, and iodine in salt).

These are the supplements a top dietitian says every woman should consider taking: 

With that in mind, there are definitely some vitamins and minerals that are almost always needed when following a vegan or vegetarian diet. Below are some of the most common culprits experts say to prioritize (although you should certainly consult with your health practitioner for more specific guidance).

Keep reading for the lowdown on vitamins needed for vegans and vegetarians:

1. Vitamin B12

Vitamin B12 is a water-soluble vitamin that’s bound to protein in food. It’s required for proper red blood cell formation, neurological function, and DNA synthesis. Low levels of B12 can lead to fatigue, weakness, constipation, loss of appetite, and neurological changes (numbness and tingling in the hands and feet, depression, confusion, dementia, and poor memory). Animal products are our main food source of vitamin B12, which makes it difficult to get enough B12 if you’ve gone plant-based (unless cow’s milk is still a part of your diet).

While you can get B12 in fortified plant foods (cereal, plant-based beverages, nutritional yeast, soy products, and meat alternatives), it is one of the key vitamins needed for vegans and vegetarians. “B12 supplementation is cheap and widely available. I usually recommend taking it daily to be on the safe side,” says Caspero. To meet your RDA (recommended daily allowance) and account for lower absorption and uptake in supplements, vegans should supplement with 5 micrograms per day.

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2. Omega-3 fatty acids/DHA

You’ve probably heard the hype over omega-3 supplements, and it’s for good reason: these fat molecules make up part of the membranes that surround the cells in your body. They also play a role in the healthy functioning of your heart, blood vessels, lungs, immune system, and hormone (endocrine) system.

There are three main types of omega-3 fatty acids:

  • alpha-linolenic acid (ALA), found in flaxseed, walnuts, chia seeds, hemp seeds, soy, and canola
  • eicosapentaenoic acid (EPA), found mainly in seafood, such as salmon, sardines, trout, and herring
  • docosahexaenoic acid (DHA), also found in fish—and viewed as the most beneficial for brain and heart health

Our bodies can make EPA and DHA from ALA, explains Vandana Sheth, RD, author of My Indian Table: Quick & Tasty Vegetarian Recipes. That means it is possible to meet your omega-3 needs by consuming about two grams per day of ALA (found in 1.5 teaspoons of flaxseed oil). But she often recommends that vegetarians or vegans take an algae-based DHA supplement to boost their DHA levels since the conversion process isn’t super-efficient.

Shop now: Nordic Naturals Algae Omega, $42

3. Vitamin D

Depending on your diet, you may need to supplement with vitamin D—a fat-soluble vitamin that your body can produce when exposed to sunlight which supports strong bones and teeth and plays a role in immune function and glucose metabolism. Why? Animal foods are a major source of vitamin D for many people, says Sheth.

Mushrooms grown in UV light do provide some vitamin D2, but it may not be as easy for the body to absorb as the D3 found in animal products, notes Sheth. Fortified foods such as fruit juices, plant-based milk, and cereals can usually help you to meet your vitamin D requirements, she adds.

Still, Caspero typically recommends supplementing with vitamin D to her plant-based clients, making it yet another vitamin needed for vegans and vegetarians. “Fortified dairy foods are the most common source in the diet for most Americans, especially as many individuals are reducing direct sunlight exposure…or don’t have access to direct sunlight enough every day,” she says.

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4. Iodine

“Most Americans consume iodine through dairy food, but as more individuals choose sea salt or Himalayan salt, they may not get enough iodine through plant foods,” Caspero says. That’s why she sometimes recommends iodine for people on a plant-based diet.

Iodine is a trace element that’s naturally present in animal foods and added to some types of table salt. It’s an essential component of thyroid hormones and may play a role in immune function.

That doesn’t mean you necessarily have to take an iodine supplement. “I recommend cooking with iodized salt,” says Caspero.

5. Calcium

You probably know that calcium (along with vitamin D) helps build strong bones and teeth. If you have fortified plant drinks, Caspero says you’re getting the same amount of calcium (sometimes more) than you’d get in dairy milk; research shows that calcium absorption is the same in both.

To hit the recommend 1000 to 1200 milligrams per day, use fortified plant-based milk anywhere you might otherwise use cow’s milk, suggests Caspero. “Make sure you shake it before consuming, since the calcium may often settle in the bottom of the container,” Sheth suggests. Other plant-based sources of calcium include leafy greens, broccoli, tempeh, tofu, tahini, almonds, black beans, seeds, blackstrap molasses, and oranges.

6. Iron

Iron is a mineral that’s an essential component of hemoglobin in your red blood cells that transfers oxygen from your lungs to your cells. It’s also required for cellular functioning and the creation of some hormones, among other functions. While Caspero says plant-based foods contain loads of iron, it’s a type of iron (non-heme) that’s less readily absorbed by our bodies than the type of iron (heme) in animal-based foods, so it’s important to eat more.

Plant-based sources of iron include leafy green vegetables (like spinach and swiss chard), dried figs, raisins, tempeh, almonds, and pistachios. You can boost your absorption of iron four- to six-fold by eating plenty of vitamin C-rich foods, suggests Caspero. Sheth adds that you should avoid drinking coffee or tea with meals and take calcium supplements between meals, as they can interfere with iron absorption.

There is one time that Caspero does recommend taking iron supplements: during pregnancy and possibly postpartum. “Needs are fairly high, and adding in a supplement is an easy way to ensure you’re eating enough of this critical nutrient,” she says. If that’s you, talk to your doctor for guidance on a supplement option.

7. Zinc

Zinc is also widespread in smaller amounts in plant-based foods. But, similarly to iron, it’s harder to absorb from plants than animal sources. “Since zinc isn’t stored in the body, it’s important for vegetarians to eat zinc-rich foods every day,” says Sheth, especially if you’re pregnant.

Zinc is a mineral that plays a role in immune function, protein and DNA synthesis, wound healing, and cell division. The zinc in soaked and sprouted grains, beans, and seeds as well as fermented foods (like tempeh) is better absorbed by your body. “I don’t recommend a zinc supplement, but I do recommend consuming sprouted grains where possible to help increase zinc absorption,” says Caspero. Other plant-based zinc sources include fortified cereal, wheat germ, corn, oatmeal, pumpkin seeds, cashews, nutritional yeast, and chickpeas.

If you’re new to a plant-based diet, the above list may seem long. If you feel overwhelmed, Sheth says a registered dietitian-nutritionist specializing in vegetarian nutrition can help evaluate your diet, assess your needs, and guide you with a customized plan.

Ultimately, adding more plants to your diet can only benefit your health—as long as you’re aware of your intake of these key nutrients. “The vast majority of research shows that a predominantly plant-based diet is best. And it doesn’t have to be [exclusively] vegan or vegetarian,” Caspero says.

Looking for more plant-based intel? Here’s an RD’s guide to protein for vegans and vegetarians: 

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