15 Vitamins (and Supplements) Nutritionists Don’t Take—So You Shouldn’t Either

Whether the pills interact with medications or the health claims don't hold up, these vitamins and other supplements are the ones experts say you're better off without.

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Let food be your medicine

Americans love pills—the nation spends about $12 billion a year on supplements. That’s a lot of money when you consider you can get what you need from your meals: Nutritionists tend to prioritize eating healthy, which allows them to get the nutrients they need from food. That’s why these wellness pros warn against overdoing it on certain ones—and skipping other supplements altogether. Here’s what you need to know.

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Looking for long, healthy hair and nails? Biotin pills may not be the miracle you were hoping for. “Some supplements don’t have much evidence that they work,” says Ginger Hultin, a Seattle-based registered dietitian, nutritionist. “Take biotin, for example—unless there is an outright deficiency, it’s not proven to help. It’s generally a best practice to get the nutrients you need from food if you can.” Foods naturally rich in biotin include eggs, salmon, sunflower seeds, sweet potato, almonds, spinach, broccoli, and dairy like milk, cheese, and yogurt. (Biotin vs. collagen: here are the differences you should know.)

Detail of a breakfast bowl of cereal with fruits and yogurt (brighter shadows with color filter)
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Did you decide, on your own, to start taking iron supplements? That could be dangerous. “Iron is sometimes prescribed based on certain medical conditions, but use caution—it can have unpleasant side effects, including stomach upset and constipation,” says Hultin. Too much iron could even lead to a condition called hemochromatosis, which can cause an irregular heartbeat, cirrhosis of the liver, and even cancer. Hultin prefers to use an individualized approach based on lab data to help determine which supplements her patients actually need. “This is another one to take only if you need to, and in the doses recommended by your doctor,” she says. Instead, she suggests ensuring that you get the mineral from food, such as fortified breakfast cereal, oysters, beans, dark chocolate, tofu, lentils, spinach, meats like beef and chicken, and these other sources of iron.

Red pills

Red yeast rice

If you’re trying to lower your cholesterol, you may have turned to red yeast rice. “While there is some evidence for treating high cholesterol levels with red yeast rice, it has side effects that should be monitored carefully by a physician,” says Hultin. “And because this is a supplement that acts in many ways like a medication, it would be very unsafe to take it at the same time as a cholesterol-lowering medication.” According to the National Center for Complementary and Integrative Health, some red yeast rice products contain a contaminant called citrinin, which can cause kidney failure. It’s also unsafe to use while pregnant or breastfeeding. Watch for these 13 other supplement-medication combinations you should avoid.

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Vitamin A

Even though vitamin A is important for immune health and vision, most Americans are not deficient in it and should not be supplementing with it, says Arielle Levitan, MD, co-founder of Vous Vitamin, and co-author of The Vitamin Solution: Two Doctors Clear the Confusion About Vitamins and Your Health. “It is readily available in many food sources, including fruits and vegetables, and many foods are fortified with it,” she says. “It is a fat-soluble vitamin, so even if you don’t take in too much, what you do consume stays in your fat cells for a long time.”


Nickel, chromium, zinc, copper

These heavy metals, often found in multivitamins, play important roles in different bodily functions. However, you need them in only trace amounts—which you likely obtain from food. “They do not leave your body easily, so a little goes a long way,” says Dr. Levitan. “Taking daily extra doses could potentially cause harm, as these metals can deposit in different parts of your body, such as your brain and bones. There has also been a question of the association of heavy metals with dementia.” Unless you have a proven, profound deficiency (often because of a chronic gastrointestinal illness), you should not take these on a daily basis.

Healthy Organic Red Ruby Grapefruit on a Background
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Vitamin C

When an immune-boosting nutrient is this easy to obtain through food, there’s simply no need to supplement. “Plus, our body does not store extra vitamin C,” says registered dietitian Jenn LaVardera, owner of Hamptons RD. “This means that when you go above and beyond your daily needs, your body simply eliminates the rest instead of saving it up for later.” LaVardera warns that if you take megadoses over 2,000 mg, it can cause diarrhea, nausea, vomiting, headaches, and cramps. If you are getting a few servings of fruits and vegetables each day, you are likely meeting your vitamin C requirements. The daily recommended amount is 75 mg for women and 90 mg for men—you can get that from a cup of strawberries or broccoli (about 80 mg each). Other good sources include citrus fruits, tomatoes, bell peppers, and cauliflower.

A shot of an open bottle with yellow pills.

Folic acid

You may have heard that folic acid supplementation is crucial for pregnant women or those trying to conceive. However, registered dietitian Lauren Manaker, owner of Nutrition One Counseling, recommends folate instead; there’s a chance that infants exposed to folic acid in the womb may have a higher risk of food allergies, according to American Academy of Allergy, Asthma & Immunology. “To be on the safe side, I obtain my folate needs through food, and if a client is in need of supplementation, I only recommend the natural folate form instead of the synthetic folic acid,” she says. (Know the 22 warning signs your vitamins won’t work.)

Big oblong orange tablets of multivitamin complex


“Multivitamins are definitely the number one supplement that clients have been convinced that they need,” says registered holistic nutritionist Jenni Bourque, cofounder of Naughty Nutrition. She points out that while people who have severe digestive issues like Crohn’s or celiac disease, or illnesses that affect the way nutrients are absorbed, may need to supplement with a multivitamin, the rest of us can take a pass. Some vitamins and minerals compete for absorption in the body, she explains; when you have them all in one pill, you could end up missing out on key nutrients. For example, iron competes for absorption with other minerals like calcium, magnesium, and zinc. “If you have poor nutrition, the best thing you can do for your body is to start cleaning up your diet and asking your doctor to run tests to see if you have any true deficiencies or hormonal imbalances,” she advises. “And if you have a true vitamin deficiency, it’s best that you supplement with that specific supplement to get the full benefit.”

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Vitamin D2

First, let’s start with a primer about this bone-health-boosting vitamin: The two major types of D vitamins are D2 and D3. Vitamin D3 is the type your body makes when sunlight hits your skin, and it’s the form that boosts your blood levels more readily. Vitamin D2 is made by plants, and your body doesn’t seem to absorb it as efficiently. “Vitamin D3 supplements are typically higher quality as well, so it’s the one you should take if you have a deficiency,” says Mirna Sharafeddine, co-founder of Naughty Nutrition. “Make sure to monitor your levels, as vitamin D is fat-soluble and too much of it can build up in the body and become dangerous. If you are vegan, it may be harder for you to find vitamin D3.” It’s synthesized from the fat in lamb’s wool or fish oil, although there are some varieties derived from algae. Oh, and if you need a boost of D3, you could also spend some time outside. Look into these 8 silent symptoms that you aren’t getting enough vitamins—and the best food fixes.

Juniper berries spilled from a spice jar
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Antioxidant blends

It seems like everywhere you turn, there are product labels boasting high levels of antioxidants. Once again, getting these from food in normal amounts may be much healthier, experts warn: “Our bodies are designed to only take in a certain amount of food and nutrients in a day, and nowhere in nature do you find a food that is loaded with as many antioxidants as some of these supplements are,” says Bourque. “In some cases, high levels of certain antioxidants have been linked to an increase in the risk of heart disease and certain cancers.” Also, some of these high-dose antioxidants can interfere with medications. If you are looking to get more antioxidants in your diet, Bourque recommends eating more fruits, vegetables, and even dark chocolate.


B vitamins

Many people take B vitamins to boost their energy, but high doses could be dangerous. Men who regularly took larger amounts of B6 and B12 had higher risks of lung cancer, according to studies published in the Journal of Clinical Oncology. Some people may benefit from a B complex, though: “If you are pregnant, have a compromised gut, are vegan/vegetarian, are taking certain medications, or are older, you may want to get tested to see if you need to supplement,” Sharafeddine says. You can likely get an adequate amount of B vitamins through whole grains, dark leafy greens, fish, eggs, or poultry.

Japanese seaweed wakame


Iodine is vital for your thyroid, and your body can’t make it. That means you need it from your diet—and that’s why food has been fortified with the mineral for decades (think of iodized salt, for example). “Thyroid health and your entire metabolism are dependent on iodine,” says Bourque. Some people tout the supplements as thyroid helpers; Bourque warns that if you already have a thyroid issue, taking excess iodine may exacerbate the condition. Plus, excess iodine can also cause stomach issues, runny nose, and headaches. If you think that your diet is low in iodine or you’re worried about a deficiency, says Bourque, talk to your doctor before trying a supplement. You can also try eating food sources of iodine, such as seaweed (nori and kelp are great examples), cod, shrimp, tuna, eggs, and prunes. Now check out these 12 vitamin mistakes you may not realize you’re making.

Medically reviewed by Elisabetta Politi, CDE, MPH, RD, on July 02, 2020

Jill Schildhouse
Jill Schildhouse is an award-winning writer and editor with 23 years of experience in print and digital publishing. As a full-time freelancer since 2017, she regularly covers health and wellness, travel, beauty, e-commerce, and sustainability, for national outlets.
Jill regularly contributes to Travel + Leisure, BRIDES, TripSavvy, Insider, USA TODAY, Reader’s Digest, Taste of Home, and Southern Living. Her bylines have also appeared in Oprah Daily, People, Health, Cosmo, Women’s Health, Men’s Health, Oxygen, Better Nutrition, Clean Eating, Vegetarian Times, Good Housekeeping, Elle Decor, Popular Mechanics, Better Homes & Gardens, and Esquire. This avid traveler has visited 37 countries and is based in Phoenix, where she lives with her fiancé and toy schnauzer.