Supplements & Drugs

Do they get along? Many drugs can deplete nutrients. Read on to learn what you can do to counteract these effects.

Not surprisingly, questions about drug-nutrient interactions are becoming more common—nearly half of Americans are taking at least one prescription drug, according to the Centers for Disease Control and Prevention.


We often hear about dangers of mixing supplements and drugs, but rarely-publicized scientific evidence shows that nutrients can just as often reduce drug toxicity and side effects or make medications work more effectively, sometimes at lower dosages. Yet in most doctors’ offices, the subject is virtually taboo.

“Don’t ask, don’t tell,” is the prevailing attitude, says Leo Galland, MD, a board certified internist, director of the Foundation for Integrative Medicine in New York City ( and a longstanding leader in the field of nutritional medicine.

Doctors don’t ask about supplement use because, he says, “If you told them, they wouldn’t know what to do with the information.” And patients don’t tell because they’re worried their doctor will say, “Don’t do this.”

Deciphering the Maze

In medicine today, Galland is arguably the world’s most knowledgeable professional when it comes to the influence of nutrients and drugs upon each other. More than 10 years ago, he began studying scientific literature on the subject, initially spending more than 1,000 hours analyzing studies. Then he began creating a database, and ever since, has continued to review emerging relevant research.

“I was pretty amazed at the large number of drugs that either depleted or interfered with the activity of specific nutrients,” he says. And, he discovered that negative effects of supplements on drugs are mostly based on anecdotal reports.

“That doesn’t mean they’re not important, since the first goal here is not to do anything harmful,” he points out. “But the positive interaction data is actually more scientifically sound, because most of that is based upon controlled studies.”

The result of his ongoing work is, a site where anyone can freely enter the names of drugs and supplements and get a complete summary of scientific findings about both positive and negative interactions, and helpful nutrients and herbs.

In the United States, says Galland, there are almost 900 drugs and commonly prescribed drug combinations. Almost
400 may deplete specific nutrients, and over 300 have been shown to interact with dietary supplements—with adverse and beneficial effects equally common.

“What really matters is the specifics of the interactions,” says Galland, because each individual’s regimen of supplements and use of medications is unique. However, there are some general principles:

  • Drugs can deplete nutrients.
  • Nutrients can alter the way a drug is metabolized, increasing or decreasing its effectiveness, toxicity levels, and safety.
  • Depending on the drug, various nutrients can enhance its benefits or reduce side effects and toxic damage.

These, says Galland, are some of the most common interactions and their underlying mechanisms:

CoQ10 (Ubiquinol) Depletion

A depletion of CoQ10 by statin drugs, widely used to lower cholesterol, is one of the most common, well documented and well understood interactions. CoQ10 is synthesized in the body. When statins interfere with the production of cholesterol in the liver, they simultaneously interfere with the production of CoQ10. Taking additional CoQ10 may correct the shortage, but sometimes the situation can be more complex.
People who take statins often take additional medications. As an example, diuretics to lower blood pressure interfere with the body’s ability to use CoQ10, and if these are being taken in conjunction with statins, there is a greater depletion.

Vitamin E can also reduce CoQ10 levels in a different way. When your body uses vitamin E to fight free radicals, the vitamin becomes oxidized and CoQ10 is used to recycle it back into an antioxidant form. In the process, CoQ10 gets used up. This mechanism may account for some negative results in trials of vitamin E among patients with heart disease.

“A single depleting effect may not be significant,” says Galland, “But multiple effects can be significant, and supplements as well as drugs may enter into the mix.” In some cases, it’s a good idea to get a blood test to check CoQ10 levels, and supplement according to individual needs.
Look for the ubiquinol form of CoQ10, which research has found to be highly bioavailable.

B12 Depletion

Metformin is well known as a medication to treat diabetes. Because it enhances the function of insulin, it may also be prescribed for weight loss or polycystic ovary syndrome (PCOS). Metformin depletes vitamin B12 by blocking its absorption, but taking the drug with calcium prevents the depletion without detracting from the drug’s benefit.

For anyone who has used metformin longer-term, Galland recommends getting tested for B12 levels—below 400 pg/ml may indicate deficiency, although technically, 200 is the deficiency threshold. A more sensitive B12 test measures serum methylmalonic acid in blood or urine; levels are elevated when B12 is low.

B6 and Tyrosine Depletion

Birth control pills deplete vitamin B6, more so with stronger prescriptions. To reduce general side effects, Galland suggests taking a B complex supplement. One particular side effect, depression, can stem from a depletion of the amino acid tyrosine. Although tyrosine supplements can correct the problem, they should be used with caution, as too much tyrosine can cause heart palpitations and other side effects

Nutrients Helping Drugs

With any drug, there may be various nutrients that enhance its action. These are some examples.

  • Fish Oil: Omega-3 fatty acids have the greatest number of studies indicating beneficial interactions with medications.
    In the case of anti-inflammatory drugs for arthritis, for example, fish oil can lead to decreased drug dosages. “The omega-3s create a milieu in the cell that is anti-inflammatory,” says Galland, “And then you don’t need as much of the drug.” In studies documenting effectiveness, fish oil supplements provided 3 to 4 grams daily of an EPA/DHA combination. Studies have found no negative drug-fish oil interactions.
  • N-Acetyl-L-Cysteine (NAC): A special form of the amino acid cysteine, NAC detoxifies and enhances internal antioxidant production. It improves the actions of the ACE-inhibitor class of blood pressure-lowering drugs and nitrate drugs, such as nitroglycerin, taken for angina.

Protection Against Toxicity

Specific nutrients protect against harmful side effects of different drugs. For example, NAC helps to guard against toxicity from acetaminophen (such as Tylenol) and may reduce side effects of chemotherapy.

Nonsteroidal anti-inflammatory drugs (NSAIDs, which include aspirin and ibuprofen), pose a significant risk of gastrointestinal, or GI, bleeding. With aspirin, says Galland, “Taking any amount triples your risk of being hospitalized with a major GI bleed.” These nutrients offer protection: For aspirin, vitamin C and DGL (deglycyrrhizinated licorice); and for other NSAIDs, glutamine and colostrum.

Dangerous Interactions

Of all supplements and herbs, St. John’s wort has the greatest number of negative interactions, with about 30 drugs. “It’s such a powerful inducer and blocker of enzymes in the liver and the intestine, it alters the drug levels,” says Galland. In the case of birth control pills, the herb can speed up breakdown of the hormones to reduce the effective dose in half, causing them to fail.

Other common ones:

  • Calcium: The mineral binds with many drugs, decreasing absorption. For example, calcium significantly impairs the effectiveness of many antibiotics, including those with names that end in “-cycline;” both synthetic and natural thyroid hormone prescriptions; and L-dopa, a class of drugs used to treat Parkinson’s disease. Such medications and calcium should be taken at different times of day.
  • Magnesium: In large doses, magnesium has the same effect as calcium, and should be taken at a different time than a drug.

Although drugs save lives in many situations, whenever possible, Galland recommends considering other alternatives. “Basically, 80 percent of what’s wrong with people in America can be treated without drugs,” he says. “It requires more effort to live a healthy lifestyle, but I think that
it’s a good thing not only for the body, but for the soul.”

What To Do

Check Your Drugs and Supplements Visit Enter any drugs you take, prescription and over-the-counter, and all your supplements. For supplement formulas, have labels handy, as you will need to enter individual nutrients—not product names. Use the information to discuss the best options with your doctor.

Where to Find Physicians Trained in Nutrition

  • The American College for Advancement in Medicine:
  • The Institute for Functional Medicine:

Questions to Ask a Doctor

When looking for a physician who is knowledgeable in nutrition, Galland suggests asking these questions:

  1. How many other patients have you treated, nutritionally, for the condition I have?
  2. What were the results?
  3. What recent nutritional discovery has been of greatest interest to you?

“There’s a constant outflow of new research data,” he says. “And doctors that do nutrition should have their finger on that pulse.”

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Vitamin Shoppe Ubiquinol

The Vitamin Shoppe Ubiquinol Softgels deliver 50 mg of ubiquinol, the more bioavailable, active form of CoQ10, levels of which are depleted by statin drugs.

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