What Happens to Your Body When You Take Too Many Supplements

Reviewed by Dietitian Jane Leverich, M.S., RDN

Key Points

• Taking high doses of certain supplements can damage your liver or increase kidney stone risk.

• Some supplements may interact with medications or interfere with nutrient absorption.

• Take supplements only when needed and choose products tested by an independent third party.

Want longer hair, strong bones, a brighter mood or an iron-clad immune system? There’s a supplement for every want, need and shortcoming, right next to the toothpaste on grocery store shelves. Approximately 61% of Americans take at least one supplement, while 16% regularly take four or more. While supplements can have their place, taking too many can come with unwanted and even dangerous side effects.

More isn’t always better with supplements, even if they’re made with natural ingredients or come from a reputable brand. Dietitians explain what can happen when your supplement stack gets too big, how to take supplements safely and whether you actually need one in the first place.

How Taking Too Many Supplements Affects Your Body

You Could Damage Your Liver

Your liver is your body’s main filtering system and also stores certain nutrients. “Since fat-soluble vitamins are stored in the liver, consuming these in excess, such as vitamin A, over time can lead to severe liver problems,” says Erin Person, M.S., RD.

Unlike water-soluble vitamins, which the body mostly excretes through urine, excess vitamin A can accumulate in the body. Taking high doses of vitamin A supplements over time can cause toxicity and, in severe cases, liver damage.

Certain herbal supplements can also cause liver damage. These products include green tea extract, ashwagandha, kava, turmeric and black cohosh, as well as vitamin B3. Having a preexisting liver condition or taking more than the recommended dose of certain supplements can increase the risk of liver damage.

Your Medications May Not Work as Intended

While you don’t need a prescription to buy a supplement off the shelf, supplements can affect your body in meaningful ways and may interact with medications you’re already taking. Depending on the supplement and medication, an interaction can make a drug less effective or increase the risk of side effects. For example, calcium and iron supplements can interfere with the absorption of levothyroxine, a common thyroid medication, making it less effective.

Some supplements may also affect blood clotting. Garlic, ginkgo biloba and fish oil, for example, have been associated with potential internal bleeding, especially when combined with pharmaceutical blood thinners like warfarin.

You Could Cause Nutrient Imbalances

You may take supplements to improve your nutritional status, but combining too many can backfire. “Taking too many supplements at the same time can interfere with the absorption of certain nutrients in the body,” says Person. In some cases, nutrients can compete for absorption, with one crowding out the other.

“For example, when taking calcium at the same time as iron, the calcium may block the ability to absorb iron since they are absorbed through the same pathways,” says Person. For this reason, it’s better to take calcium and iron at separate times of day.

Zinc and copper can compete for absorption, too. “Someone may be taking zinc on a regular basis thinking that it may help their immune system, when in fact it can cause an imbalance of other micronutrients,” says Julie Stefanski, M.Ed., RDN. Over-the-counter zinc supplements can support your immune system short-term, but taking high doses over time can reduce copper absorption and potentially lead to copper deficiency, which can cause anemia and neurological problems.

Your Risk of Kidney Stones Could Increase

Your kidneys filter waste products from your bloodstream, and some supplements can affect how much of certain substances ends up in your urine. If you’re prone to kidney stones, it’s worth paying attention to what you’re taking.

“Many herbal supplements, especially those that contain cinnamon, beet, turmeric, black pepper or spinach, can contain incredibly large doses of oxalate,” says Melanie Betz, M.S., RD, CSR, FNKF, FAND. Eating these foods in smaller amounts may not be problematic, but adding a concentrated supplement form may be too much. If you’ve ever had an oxalate kidney stone, be cautious with supplements containing these ingredients, including “whole food” supplements and greens powders.

“Vitamin C can also increase the liver’s production of oxalate, significantly raising urine oxalate levels and oxalate kidney stone risk,” says Betz. High doses of vitamin C supplements may increase kidney stone risk in susceptible people, although the risk varies by individual. Research has also linked certain calcium and vitamin D supplementation regimens with an increased risk of kidney stones.

Should You Take Supplements for Better Health?

A quick scroll on TikTok and you’ll be convinced you need a supplement to feel your best. But experts say supplements aren’t always the best route to better health.

“Supplements are meant to supplement a healthy, well-balanced diet,” says Betz. That means a balanced eating pattern, regular physical activity, adequate sleep and stress management should be your foundation, with supplements helping fill nutritional gaps when needed.

If you think you have nutritional gaps or may benefit from a specific supplement, talk with a registered dietitian and your health care provider about choosing the right product and dose. A supplement may be helpful if you have a diagnosed deficiency, follow a restrictive eating pattern or have a health condition that affects nutrient absorption. But taking one without a clear need doesn’t necessarily offer additional benefits.

Are Supplements Safe for Everyone?

Even if a supplement is natural, contains ingredients found in food or is advertised by your favorite influencer or celebrity, that doesn’t mean it’s safe for you. “There is a potential risk of harm with supplements for anyone,” says Betz, emphasizing that people with health conditions, especially those that make it harder to process or eliminate substances from the body, such as kidney or liver disease, need to use extra caution.

Even if you’re generally healthy and don’t take medications, it’s important to be thoughtful when choosing a supplement to take. In the U.S., dietary supplements aren’t regulated in the same way as prescription medications. Manufacturers are responsible for ensuring their products meet applicable requirements, but quality and ingredient accuracy can vary.

Choosing a third-party-tested supplement is one way to help assess product quality. “Buying third-party-tested products ensures the supplement contains what is on the label for ingredients and amounts, and that the supplement is free of impurities,” says Person. “The labels to look for are NSF, USP, BSCG and Informed Choice or Informed Sport to ensure third-party testing.”

If you’re not sure whether a supplement is right for you or you’re unclear on the correct dose, a registered dietitian, health care provider or pharmacist can help you choose the safest, most effective option.

Our Expert Take

When it comes to supplements, more isn’t always better. Taking too many supplements—or taking high doses of certain nutrients—can be harmful. Supplements may interact with one another and with medications, and some can increase the risk of liver damage or kidney stones. If you can’t meet your nutritional needs through food alone, a registered dietitian, health care provider or pharmacist can help you find the right supplement and dose to support your needs. To ensure the bottle contains what the label says, look for supplements that have been third-party tested and come from reputable brands.

Frequently asked Questions

How many supplements is too many to take in one day?

There is no exact number of safe supplements to take in one day. Take only what you need, and make sure they don’t contain ingredients that can interact with each other or your medications. Be especially mindful of products containing multiple vitamins and minerals, since you could end up taking more of a nutrient than you need when you combine them with other supplements.

What vitamins and minerals can you take too much of?

Many vitamins and minerals can cause adverse effects when taken in excessive amounts. Although the body excretes some water-soluble vitamins through urine, that doesn’t mean they’re harmless in high doses. Most nutrients have established tolerable upper intake levels, which are the maximum daily amounts unlikely to cause adverse health effects for most people.

Nutrients that can cause problems when consumed in excess include vitamins A, B6, B3, C, D and E, as well as calcium, magnesium, zinc and selenium. The risks vary by nutrient, dose and individual health factors, so check with a health care professional before taking high-dose supplements.

Can I take all of my supplements at the same time?

It depends on which supplements you’re taking. Some nutrients can interfere with one another’s absorption, while certain supplements can interact with medications. Some supplements are best taken with food, and others may have specific timing instructions. Follow the product directions and ask your health care provider or pharmacist whether you should separate any supplements or medications. The goal is to take only what you need at appropriate doses and in a way that’s safe for you.

Read the original article on EatingWell