Dietary supplements 101: What you need to know before taking vitamins & minerals

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More than half of adults in the U.S. (57.6%) take dietary supplements, yet most people don’t know much about them.

WellTuned spoke with Dr. Crystal Cooper, clinical pharmacist at BlueCross BlueShield of Tennessee, to find out what people need to know.

What are dietary supplements?

Dr. Cooper: A dietary supplement is a product you take by mouth that contains a “dietary ingredient.” This includes vitamins, minerals or herbs. They often come in tablets, capsules, powders or liquids.

Why do people take supplements? 

Dr. Cooper: There are many reasons:

  • Some people take them to make sure they get enough essential nutrients if their eating habits don’t cover those needs.
  • Some take them to help treat medical conditions diagnosed by their provider.
  • Others take supplements hoping to boost energy or get a good night’s sleep.

What’s the difference between a vitamin and a mineral? 

Dr. Cooper: Vitamins are organic, meaning they’re made by living things such as plants and animals. For example, carrots contain beta carotene, which the body turns into vitamin A that’s important for vision and reproduction.

Minerals are inorganic and found in the earth (rock, soil). For example, mushrooms absorb copper from the soil, which your body uses to make red blood cells.

Which vitamins and minerals are most beneficial to your health?

Dr. Cooper: Your body needs all vitamins but only some minerals. It’s possible for most people to get all the nutrients they need by eating a healthy, balanced diet. But supplements can be useful for filling in gaps. If you’re curious about which supplements would benefit your health most, your provider can draw labs, take a personal history and let you know.

What are the most common supplements?

Dr. Cooper: The most common supplements are:

  • Daily multivitamins
  • Vitamin D, which supports your immune system and helps your body absorb calcium
  • Omega-3 fatty acids, which may decrease inflammation
  • Calcium, which builds strong bones and teeth
  • Vitamin B12, which helps keep your blood and nerve cells healthy
  • Iron, which helps your body create new red blood cells

Supplements are also used for some medical conditions:

  • Calcium and Vitamin D are used to prevent and treat osteoporosis.
  • Folic acid is recommended for all females who are or may become pregnant.
  • Iron treats certain types of anemia.

Are any supplements harmful?

Dr. Cooper: Many supplements contain active ingredients that can have strong effects in the body. Some can interact with other medicines to cause serious health problems. Others can increase your risk of bleeding or, if taken before surgery, change your response to anesthesia.

You’re most likely to have side effects if you take supplements: 

  • At high doses
  • In place of prescribed medicines
  • In combination with other supplements or medicines

Supplements fall into 2 ranges:

  1. A therapeutic range refers to a level in your body that is medically helpful but not dangerous.
  2. A toxic range is a level that can cause damage or harm to the body.

Dr. Cooper: Some people believe more is better for any substance. Yet, large doses of some vitamins and minerals can be dangerous and harmful.

For example:

  • High doses of iron can cause an upset stomach, constipation, nausea, vomiting and fainting.
  • Extremely high doses of iron can cause organ failure, coma and convulsions.

Always talk with your healthcare provider before starting or stopping a supplement. And let your doctor and pharmacist know which supplements you’re currently taking. Be alert to the possibility of a bad reaction, especially when starting a new product.

How closely are supplements regulated?

Dr. Cooper: Dietary supplements are not regulated by the FDA as drugs. They’re regulated as food. So, supplement makers don’t have to get approval from the FDA to sell their products. And, it’s their responsiblity to make sure they’re safe, and that the contents of the bottle matches the label.

That means:

  • There’s no regulatory agency making sure that labels match what’s in the bottles.
  • You risk getting less, or sometimes more, of the listed ingredients.
  • All the ingredients may not even be listed, or the bottle could contain contaminants like heavy metals.

The FDA does watch for products that may be unsafe or make false or misleading claims. But, they only do this after the product is already on the market.

For the best result, choose a brand with a third-party certification. This is when an independent agency tests the supplements to make sure they’re properly made and contain the listed ingredient. Ask your pharmacist which products have this done before purchasing a supplement.

What do people need to know before starting supplements?

Dr. Cooper: Remember 5 things:

  1. Vitamins and minerals are already added to some foods, especially breakfast foods. So, you may already be getting more nutrition from your diet than you think.
  2. Ask your healthcare provider before taking a supplement, especially before taking one in place of or in combination with prescribed medicines.
  3. If you’re scheduled to have surgery, tell your provider about all supplements you take.
  4. Supplements are not intended to treat, cure or reduce the effects of disease.
  5. Keep in mind the term “natural” doesn’t always mean safe. Some all-natural products can harm the liver and other organs.

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Ashley Brantley

Ashley Brantley has been writing about food, culture and health for more than a decade, and has lived in three of Tennessee’s four major cities (Memphis, Nashville and Knoxville).

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Ashley Brantley has been writing about food, culture and health for more than a decade, and has lived in three of Tennessee’s four major cities (Memphis, Nashville and Knoxville).