These are the supplements you should avoid taking with your medications

With age and new (or more) chronic health conditions, it\’s common for people to need prescription drugs. Many people also use over-the-counter products and supplements to meet their health needs.

While the use of dietary supplements and medications is common, particularly among the elderly, experts say taking certain medications and supplements at the same time could have dangerous, even fatal consequences.

The National Center for Complementary and Integrative Health (NCCIH) says that many people combine supplements and prescription or over-the-counter (OTC) medications without being aware of potential interactions.

Combining certain dietary supplements and medications can lead to a variety of harmful effects, including reduced drug efficacy, increased risk of drug toxicity, and unexpected side effects, Danielle Crumble Smith, RDN, a registered dietitian, told Verywell. at Top Nutrition Coaching.

If you take medications and supplements, here are the potentially risky combinations experts say you should be aware of and avoid.

Combinations of supplements and drugs that can reduce effectiveness

Marilyn Tan, MD, a double board certified in endocrinology and internal medicine and an associate professor of medicine at the Stanford University School of Medicine, told Verywell that some supplements and vitamins can affect the absorption or metabolism of prescription drugs. There are others, such as vitamin K, that can even counteract the effects of some medications.

Here are some possible interactions to be aware of:

• Vitamin B6 and levodopa. Taking Vitamin B6 with levodopa, a drug for Parkinson\’s disease, can make drugs less effective. However, some levodopa medications also contain carbidopa, which can counteract the interaction.
• Vitamin K and blood-thinning medications. Vitamin K can counteract the effects of blood-thinning drugs such as warfarin, possibly making them less effective. If you\’re taking blood-thinning medications, talk to your provider before taking vitamin K supplements or increasing your dietary intake of vitamin K.
• Iron or calcium and thyroid hormone replacement drugs. Some supplements such as iron and calcium can interfere with the absorption of thyroid hormone replacement drugs such as levothyroxine. It is best to take these supplements and thyroid hormone replacement drugs at least four hours apart.

Potentially harmful supplements and drug combinations

According to Crumble Smith, there are also combinations of supplements and medications that can cause harmful side effects or symptoms:

• Vitamin C and antacids that contain aluminum. Vitamin C increases the absorption of aluminum from antacid medications such as Tums) which neutralize stomach acid and help relieve heartburn or indigestion. However, taking vitamin C and antacids together can lead to toxic levels of aluminum in the body. Therefore, they should be taken at least two hours apart.
• Vitamin E and blood-thinning medications. Vitamin E can increase the risk of bleeding when taken with blood-thinning medications such as warfarin. If you\’re taking a blood thinner, ask your provider before you start taking vitamin E.
• St. John\’s Wort and various drugs. St. John\’s Wort supplements can interact with many medications, including antidepressants, birth control pills, and blood thinners. St. John\’s Wort can reduce the effectiveness of these medications, and mixing them can cause harmful effects.
• Goldenseal and blood clotting drugs. Goldenseal supplements can interact with some medications, including clotting medications. The interaction can reduce the body\’s ability to clot blood, which can lead to bleeding or bruising. Given the severity of the interaction, it is often advised to avoid using goldenseal and blood-clotting drugs together.
• Ginkgo biloba and blood-thinning medications. Ginkgo biloba the supplements can also increase the risk of bleeding when taken with blood-thinning medications such as warfarin or aspirin.
• Licorice root and diuretics or blood pressure medications. Supplements that contain licorice root can interact with diuretics and blood pressure medications, making their side effects worse or even causing serious problems such as potassium imbalances or blood pressure fluctuations in the body.

If you are taking a prescription drug and are thinking about trying a supplement, talk to your provider or pharmacist.

What to do if you take these combinations

If you are prescribed medications and plan to use supplements, timing is everything. For example, Tan said thyroid hormone medications should be taken on an empty stomach and separated from supplements by at least four hours, especially if they contain calcium and iron.

Other endocrine drugs like the osteoporosis drug Fosamax and the diabetes drug Rybelsus should be taken on an empty stomach and separated from other drugs for at least 30 minutes, Tan added.

To avoid potential interactions, Crumble Smith recommends discussing dose timing specifics with your provider. As a general rule, space yourself at least two hours apart when taking supplements and medications.

When to check with your doctor

Your provider can guide you on which combinations to avoid and how to safely use supplements with medications.

In general, it\’s never a bad idea to let your supplier know if you\’re considering trying something new since you won\’t necessarily be aware of the possible risks involved.

Supplements seem harmless, but it\’s really important to consult a healthcare professional if you\’re considering starting a new supplement, said Crumble Smith. This is especially true if you are currently taking any medications.

How to control interactions yourself

You can also ask your pharmacist about drug supplement combinations when picking your medications. Pharmacists are trained to understand drug interactions, including those that can occur with dietary supplements. They also have access to comprehensive databases and tools that allow them to check potential interactions.

A pharmacist can give you advice on how to use supplements safely, check for interactions, make dose timing suggestions, or offer alternatives. In some cases, a pharmacist may be able to suggest dose adjustments that may help you avoid an interaction.

Crumble Smith said it\’s important to give a pharmacist a comprehensive list of everything you\’re taking, from prescription medicines to OTC products and supplements, as this information will help them make the most accurate assessment.

There are also several databases and online tools from reputable resources that you can use to check for potential drug-supplement interactions yourself, including:

• MedlinePlus: This website is sponsored by the National Institutes of Health (NIH) and maintained by the US National Library of Medicine. It offers a lot of information about drugs, including potential interactions between them.
• National Center for Complementary and Integrative Health (NCCIH): The NCCIH website offers general advice on the safe use of supplements and provides an overview of specific herbs and supplements.
• Drugs.com Interaction Checker: This website is a comprehensive resource for checking drug, herb, and supplement interactions. You can enter the names of the medications and/or supplements you are taking and it will show you all known interactions.

Crumble Smith said that while these resources can provide helpful information, they are not a substitute for professional medical advice.

Always consult a doctor or pharmacist before starting, stopping, or changing your medication or supplement regimen, she said.