5 Potential Benefits (And Some Risks) of Dietary Supplements

Explore the Effectiveness, Safety, and Potential Risks

Dietary supplements

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Whether you are looking to boost your nutrition or ease your joint pain, you are not alone if you take a dietary supplement to support your health and wellness. According to the Centers for Disease Control and Prevention (CDC), more than 55% of adults in the United States take some type of dietary supplement over a 30-day period.

It’s important to note that there are many products that fall under the umbrella term of “dietary supplements,” and include any vitamin, mineral, herb, botanical, enzyme, and amino acid. Additionally, these dietary supplements come in many forms—tablets, capsules, gummies, powders, tinctures, drinks, bars, and so many more.

While dietary supplements can help you meet your nutrient needs, more isn’t always better. Dietary supplements may not be compatible with you or your health, causing side effects and allergic reactions or interacting with your medication. Below you can learn more about dietary supplements and their potential benefits, along with some of the risks. 

5 Benefits of Dietary Supplements

Eating a balanced diet is the best way to get all the nutrients your body needs for good health. However, there are instances where you might benefit from a dietary supplement if you can’t get everything you need from the food you eat.

Taking a dietary supplement may prevent a deficiency, reduce risk of developing nutrition-related health problems, or boost health. Here are some of the potential benefits of taking dietary supplements.

May Prevent or Reverse a Deficiency

It may seem surprising in a country like the United States, but nutrient deficiencies are a public health concern and can lead to health problems. Iron deficiency anemia, for example, is common in the U.S., especially in children and people of childbearing age.

Iron is found in a wide variety of foods, including beef, chicken, fish, beans, and whole grains. However, some people find it hard to meet their daily needs from food alone. 

Not getting enough iron in your diet causes fatigue, makes you more susceptible to infections, and affects gastrointestinal health. It also impairs growth in children. If you’re iron deficient, you may benefit from taking an iron supplement to reverse your deficiency.

Provide Nutrients You Aren’t Getting Enough Of

Calcium and vitamin D are also nutrients of concern that many people fail to get enough of from diet alone. You need calcium and vitamin D to keep your bones healthy and strong. 

Dairy products, leafy greens, and fish with soft bones (sardines and salmon) are good sources of calcium. Vitamin D, however, is found in only a few foods, making it harder to meet your needs, even when eating a balanced diet. Taking a dietary supplement may help you get enough of these health-promoting nutrients, keeping your bones strong. 

You may also benefit from a vitamin B12 supplement if you follow a vegan diet. Animal products such as meat, dairy, and eggs are the only source of vitamin B12 and a dietary supplement may be the only way you can meet your daily needs if you don’t eat animal foods. 

Reduce the Risk of a Medical Condition

Dietary supplements may also reduce your risk of developing medical conditions like anemia (iron or vitamin B12 supplement for vegans) or osteoporosis (calcium and vitamin D supplements).

The National Eye Institute is currently researching the benefits of a special supplement called AREDS 2—which contains vitamins C and E, zinc, copper—for eye health and vision. You can't get this mix of nutrients from the food you eat. Supplementing with AREDS may reduce risk of vision changes caused by age-related macular degeneration (AMD) when taken during the early stages of the disease.

Support Overall Health

Dietary supplements may also support overall health. Multivitamin and mineral supplements, vitamin D, and omega-3 fatty acids are the most commonly used dietary supplements in the U.S.

A multivitamin may not contain 100% of all the nutrients your body needs, but it may help your bolster intake, especially on those days when eating a balanced diet is challenging. Vitamin D supplementation also is good for your bones and may support immune health. Supplementing with omega-3 fatty acids may help the body’s fight against oxidative stress and inflammation, supporting general health and well-being.

Complement Therapeutic Treatment Plans

Your health care provider may recommend dietary supplements as part of your treatment plan. Your eye doctor may recommend supplementing with AREDS 2 if you have early stage AMD. And some healthcare providers may recommend omega-3 fatty acid supplements to lower high blood triglyceride levels instead of, or in addition to, lipid lowering medication.

Not all dietary supplement products and brands are created equal, though, and it’s always recommended that you speak with an expert to source the safest, most effective option available if you do choose to use a dietary supplement.

Potential Risks of Dietary Supplements

Dietary supplements have active ingredients that affect your body. These effects may come with some risks, which is why it’s always best to talk with a healthcare provider before adding a supplement to your daily routine. 

Interactions With Medications

Dietary supplements may not work well with your prescription medication. For example, the herbal supplement St. John’s wort may reduce the effectiveness of certain medications like birth control, heart medication, and anti-HIV prescriptions.

Vitamin C is often touted as a complementary therapy for cancer treatment. But supplementing with vitamin C, or vitamin E, may decrease the effectiveness of certain chemotherapy drugs.

Side Effects and Allergic Reactions

Dietary supplements may also cause unwanted side effects, especially if you take them at high doses or instead of recommended medications. For instance, taking high doses of vitamin A or iron may cause liver damage. These supplements may also trigger an allergic reaction like itchy eyes, runny nose, or difficulty breathing.

Dietary supplements aren’t regulated like drugs and it’s up to the manufacturer of the supplement to make sure their product is safe and effective. These supplements may contain ingredients not listed, potentially making it harder for you to avoid your allergens.


Taking more than the recommended dose on the label won’t lead to better results. In fact, you can “overdose” on dietary supplements. 

Vitamin A is a fat-soluble vitamin that your body stores in the liver, which accumulates over time. Taking high doses of vitamin A can lead to toxicity within days or weeks, causing headaches, blurry vision, nausea, vomiting, and liver damage.

Ingestion of Harmful Ingredients

Natural doesn’t necessarily mean it’s safer. Dietary supplements contain active ingredients that can have a strong effect on your body and may cause harm.

Quality and Effectiveness Not Guaranteed

It’s up to the manufacturer of the dietary supplement to guarantee quality and effectiveness of their product. There are organizations that do quality testing for supplements—U.S. Pharmacopeia, ConsumerLabs.com, and NSF International—but there’s no guarantee your supplement contains quality ingredients or that it’s effective, even with the independent quality testing label.

May Not Have Any Effect

Supplement makers must follow certain labeling guidelines when making health claims about their products. However, that doesn’t always stop these manufacturers from making misleading claims like “curb appetite and balance blood sugars” or “strengthens joints.”

These claims are usually based on very little scientific evidence and your supplement may not have any positive or beneficial effects at all. Dietary supplements also can be expensive and there’s no guarantee you’re getting what you pay for.

A Word From Verywell

Dietary supplements can help meet nutrient needs and prevent health problems, but not all supplements are created equal. Before adding a dietary supplement to your daily routine, you should talk to a healthcare provider about the supplement. They can provide the personalized insight you need to make sure the dietary supplement can benefit your health and not hurt it. 

Frequently Asked Questions

  • What are three reasons for taking a dietary supplement?

    Three reasons for taking a dietary supplement include meeting nutrient needs, treating a nutritional deficiency, and preventing or managing a health condition. You may benefit from a dietary supplement if you’re not able to get all the essential nutrients your body needs from food alone.

  • Are dietary supplements safe?

    In general, dietary supplements are safe. However, you should talk to your primary care provider before adding any supplement to your regular routine. Some supplements decrease the effectiveness of medication or contain ingredients that may harm your health.

10 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. Dietary supplement use among adults: United States 2017-2018.

  2. National Institutes of Health. Office of Dietary Supplements. Dietary supplements:  What you need to know.

  3. U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2020-2025.

  4. National Institutes of Health. Office of Dietary Supplements. Iron.

  5. National Eye Institute. AREDS 2 supplements for age-related macular degeneration (AMD).

  6. National Institutes of Health. Office of Dietary Supplements. Vitamin D.

  7. Djuricic I, Calder PC. Beneficial outcomes of omega-6 and omega-3 polyunsaturated fatty acids on human health: An update for 2021. Nutrients. 2021;13(7):2421.doi:10.3390/nu13072421

  8. National Institutes of Health. Office of Dietary Supplements. Omega-3 fatty acids.

  9. American Academy of Allergy, Asthma, and Immunology. Reactions to complementary and alternative medicines.

  10. National Institutes of Health. Office of Dietary Supplements. Vitamin A.

By Jill Corleone, RD
Jill is a registered dietitian who's been learning and writing about nutrition for more than 20 years.