What to Know About Drug & Supplement Interactions | Persona Blog

Drug Nutrient Interactions: What your pharmacist wants you to know

As a community pharmacist, I notice patients browsing the vitamin and supplement aisle, oftentimes holding multiple bottles with looks of concentration. When I approach them to offer assistance on choosing a supplement the question is usually the same, “Can I take this with my medication?” I always smile. This is exactly the question I want my patients to ask before adding anything to their current medication regimen.

I know that the majority of my patients are likely using supplements in addition to the medications I dispense them every month. A Mayo Clinic study estimates that 70% of Americans take at least one prescription medication with more than half of Americans taking two, and a recent consumer survey by the Council for Reasonable Nutrition revealed that 75% use a daily dietary supplement.1,2

My goal is to evaluate these combinations and identify any potential interactions between these medications and supplements to ensure my patients are getting the most benefit and fewest side effects from these therapies.

So how do medications and supplements interact with in our bodies?

There are two main types of drug supplement interactions:

1. A supplement changes the way a drug moves inside your body.

Drugs have a predictable way of being absorbed, distributed, and eliminated from your body. When a supplement interferes or changes any step in this process, issues can arise with the effectiveness of your drug therapy.

These interactions can require you change the way you take your medications and supplements, such as spacing the time interval between taking your medicine and supplement.3  For example, calcium, iron, and zinc supplements commonly found in multivitamins can affect the absorption of some antibiotics. This interaction makes it difficult for the antibiotic to get into the blood stream and fight infection. For this reason, your health provider will advise you to take your multivitamin separately from your antibiotic by several hours.4

2.  A supplement changes the way a drug acts inside your body.

Supplements can sometimes have an additive or opposite effect of your medications resulting in an increase of certain side effects or ineffective drug therapy. These types of interactions can sometimes require additional monitoring to ensure you do not experience harmful side effects and receive the full benefit of your medication and supplement regimens.3 For example, Vitamin K is known to antagonize the blood thinner, Warfarin. Vitamin K is commonly found in multivitamins and in the foods, like leafy green vegetables. Patients taking warfarin have to closely monitor their Vitamin K intake, but are still able to take multivitamins and enjoy foods containing Vitamin K.5

So how do you safely add a supplement to your current medication regimen? Start a conversation with your health care provider about any medications and supplements you are currently taking or any changes you might want to make to your medication and supplement regimen.

A healthcare professional is more accessible than you realize. Call your local pharmacist with any questions you might have about interactions between your current medications and supplements. If you are looking to start a supplement regimen, Persona’s personal assessment takes into account your health, lifestyle, and medications by analyzing 850 potential prescription drug interactions before making any supplement recommendations. Persona nutritionists are also available to chat about the supplements they provide.

A conventional medication regimen should never discourage you from adding supplements to help achieve your health goals. Drug supplement interactions are manageable with the help of your healthcare provider, but communication is the key.


1.)  Mayo Clinic. “Nearly 7 in 10 Americans are on prescription drugs.” ScienceDaily. ScienceDaily, 19 June 2013. <www.sciencedaily.com/releases/2013/06/130619132352.htm>. Accessed April 11, 2019

2.)  Counsel for Reasonable Nutrition. “2018 CRN Consumer Survey on Dietary Supplements.” 18 October 2018 <https://www.crnusa.org/CRNConsumerSurvey> Accessed April 11, 2019

3.)  Boullata JI, Armenti VT. Handbook of Drug Nutrient Interactions. Second Edition. Humana Press, 2010

4.)  Lomaestro BM, Bailie GR. Absorption interactions with fluoroquinolones. 1995 update. Drug Saf 1995;12:314-33.

5.)  Booth SL. Dietary vitamin K guidance: an effective strategy for stable control of oral anticoagulation? Nutr Rev. 2010;68(3):178-81.

This information is not intended as a substitute for the advice provided by your physician or other healthcare professional or any information contained on or in any product label or packaging. Do not use the information from this article for diagnosing or treating a health problem or disease, or prescribing medication or other treatment. Always speak with your physician or other healthcare professional before taking any medication or nutritional, herbal or homeopathic supplement, or using any treatment for a health problem. If you have or suspect that you have a medical problem, contact your health care provider promptly. Do not disregard professional medical advice or delay in seeking professional advice because of something you have read in this article.



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