7 Facts to Know About Supplements Before Taking Them

Learn more about supplements, how they can help and which ones could pose health risks

Walk down the vitamin and mineral aisle of any drugstore and you’ll see rows of capsules, liquids, and powders — all packaged to suggest they’ll improve your health and well-being.

Supplements can appear in many forms: vitamins, minerals, amino acids, healthy oils, fatty acids, botanical extracts with active ingredients isolated from specific plants or combination of any of these.

Whether they’re shelved in sections labeled “digestive health,” “liver support,” “heart health” or dozens of others, you may be surprised to learn they may or may not have any effect at all — or could actually be harmful if taken incorrectly or in combination with prescription or nonprescription drugs.

Here are seven facts about supplements to help you make the healthiest decisions for your body.

1. Supplements are regulated, but not necessarily tested and proven through clinical trials.

The supplement industry is a $30 billion industry, with an estimated 80,000 to 90,000 supplement products in the market.

While prescription medication undergoes rigorous testing and clinical trials before making it to the consumer, supplements do not.

“The United States Food & Drug Administration doesn’t regulate the health claims made by supplement manufacturers,” says Immanuel Hausig, DO, a family medicine physician at Scripps Coastal Medical Center, Carlsbad.

“In fact, the Dietary Supplement Health and Education Act of 1994 doesn’t require that manufacturers prove supplements are safe before they are offered for sale. The manufacturers just have to prove supplements are produced in safe conditions, which is a subtle difference.”

Because they are relatively unregulated, consumers don’t realize that supplements can be inappropriate or even harmful, depending on underlying health conditions, interactions with other medications or toxic ingredients.

2. Supplements can’t replace a healthy diet and exercise.

The basis for good health is a balanced healthy diet, regular exercise, restful sleep, a good social network, not smoking, and not drinking alcohol in excess.

Vitamins, minerals, and other supplements will not replace this. They, however, can be used to fill in nutritional gaps and improve our health.

Some examples of this include:

  • Folic acid for women who are planning to get pregnant or are pregnant
  • Vitamin B12 for patients on PPI’s and H2 blockers, as stomach acid is needed to extract B12 from animal products
  • B12 for vegans and some vegetarians
  • Vitamin D3, calcium, magnesium and vitamin K for osteoporosis
  • Omega 3 fish oils for high triglycerides
  • Vitamin E for fatty liver
  • Glucosamine and chondroitin for osteoarthritis
  • Melatonin for sleep
  • Vitamin C and zinc for colds
  • “People who are taking certain medications — say, for example, proton pump inhibitors like Nexium or Prilosec, or metformin for diabetes — are known to at risk for developing certain vitamin and mineral deficiencies,” Dr. Hausig says.

He explains that prescription antacid PPIs can deplete magnesium, while glucose-management medication such as metformin can cause Vitamin B12 deficiency.

3. If you’re taking supplements, your physician should know.

Some supplements can interfere with the action of prescription medications through a number of different processes. In addition, he says, some supplements may be inappropriate for people with certain chronic diseases.

“If you are taking supplements, be sure you tell your doctor,” says Dr. Hausig.

For example, excess calcium can contribute to coronary artery disease, and niacin can elevate blood sugar in diabetics. Patients with hemochromatosis, a disorder involving too much iron in the body, should avoid iron and vitamin C.

4. Some supplements have been validated by a clinical trials.

There is strong, longstanding, evidenced-based research for some supplements, including plant sterols, omega-3 fatty acids, niacin, vitamin B6 and B12, and tree nuts.

“More and more data comes out every year about supplement effectiveness,” Dr. Hausig says.

Ideally, a study should be placebo-controlled (with some subjects taking the supplement and others taking an inert substance, or placebo); double-blind (neither the researcher nor the participants should know who is taking the actual supplement and who is taking the placebo); and large enough to establish statistical significance.

When in doubt, ask your physician.

5. Some supplements have high-risk drug interactions.

Certain supplements may interact with your medications or increase your risk of experience side effects from medications. Some supplements are known to carry an increased risk of liver injury. Others may decrease the blood’s ability to clot—these include fish oil, ginkgo biloba, garlic and vitamin K.

Additionally, excess vitamin E can increase the chances of hemorrhage or uncontrolled bleeding. Too much vitamin D may also cause non-specific symptoms such as poor appetite, weight loss and heart arrhythmias. High doses of vitamin A can cause birth defects.

The National Institutes of Health website has a database of supplement labels. If you’re currently taking prescription medication, talk with your doctor before beginning a new supplement regimen.

6. Vitamin supplements can carry side effects.

Because supplements are a wide-ranging category, they may carry the same risk for broadside effects as pharmaceutical drugs, from digestive upset and diarrhea to interfering with hormonal birth control and beyond.

The U.S. Department of Health & Human Services maintains an Office of Dietary Supplements that provides fact sheets on many common supplements, including side effects.

7. Taking more supplements doesn’t necessarily translate to better health.

There are independent testing companies that acquire samples of supplements from retailers and test them to see if they contain what they say they are, in the labeled dosage.

The U.S. Pharmacopeial USP verification program tests supplements and offers a verification logo to help consumers choose supplements that have passed lab tests in the past and contained the specified ingredients at the specified strength. NSF International and Consumer labs are other seals that ensure a high-quality standard.

“There isn’t as much quality control with dietary supplements as there is with drugs that are regulated by the FDA,” says Dr. Hausig.

Overall, Dr. Hausig says, it’s important to be an informed consumer of dietary supplements if you choose to take them.

“When it comes to dietary supplements, more isn’t necessarily better,” he says. “If you’re taking several over-the-counter supplements every day, you should definitely have a conversation with your doctor to clarify what your goals are, ensure none of them are counteracting each other or your prescribed medications, and to see if you even need to be taking them.”

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