Supplements Drug Interactions

While many people take vitamins and other supplements to maintain their health, at times, taking these supplements can be inconsequential, or even a bad idea, if people are currently taking certain types of other medications. In fact, drugs and vitamin supplements can interact negatively with each other in a variety of ways, causing:

  • a drug-related deficiency of certain nutrients
  • a medication or nutrient to lose potency
  • a person’s appetite to dramatically change, therefore shifting his nutritional needs
  • the body to be unable to absorb nutrients
  • the body to be incapable of properly using nutrients
  • toxicity, making a person mildly to severely ill.

Similarly, just as vitamins and medications can have negative interactions, so too can not taking the appropriate types and amounts of vitamins and/or medications. For example, your body isn’t able to properly absorb or use Vitamin A if it doesn’t also have enough Zinc.

As a result, make sure that you tell your doctor about all prescription medication, as well as vitamin, herb and mineral supplements, you take. Talking to your doctor about the medications you take, your current state of health and your supplement routine is key to maintaining your health, preventing potentially serious health problems and ensuring that you are taking the right supplements for you.

The range of health problems that vitamin and drug interactions can cause depends on:

  • the types of drugs and/or supplements you take
  • whether or not you suffer from any chronic or passing health conditions
  • your age
  • your current health status.

With all of these factors to consider, a vast number of potential health complications can arise due to negative drug and vitamin interactions. For the purposes of this article, we will focus on the most common types of medications that cause complications when paired with some of the more essential vitamins.

Negative Interactions Between Vitamin A and Other Medications

Vitamin A, including Retinol and Beta-Carotene, is a nutrient that is essential to:

  • healthy vision, especially night vision
  • mRNA protein production and other forms of gene expression
  • proper functioning of the immune system
  • red blood cell production
  • the healthy development of a fetus. (Vitamin A deficiencies in pregnant women can cause birth defects.)

While the body needs sufficient levels of Zinc to adequately absorb and use Vitamin A, appropriate levels of Vitamin A are necessary for the body to effectively absorb and use Iron.

Here is an outline of which types of commonly used drugs and medications interact negatively with Vitamin A:

  • Ethanol is a type of grain-based alcohol that, while used in alcoholic beverages, is also included in some psychoactive drugs, such as painkillers or antidepressants. When psychoactive medications that contain ethanol interact with Vitamin A (or a person drinks to much alcohol when taking Vitamin A), the liver suffers damage, and the body fails to properly absorb Vitamin A, potentially causing Vitamin A toxicity.
  • Neomycin is a type of antibiotic that is used as a surgical antiseptic and is often included in topical creams and eye drops. Taken orally or applied in a topical form, neomycin can slow down the body’s ability to absorb Vitamin A.
  • Tetracyclin is another type of antibiotic that is used to treat rosacea, acne and other types of bacterial infections. In both oral and topical forms, when tetracycline interacts with Vitamin A, it raises blood pressure, causing hypertension.

Vitamin B12, Folate and Other Medications

Vitamin B, including B12 and Folate, are nutrients that are key in:

  • aiding the metabolic process
  • establishing adequate levels of oxygen in the blood
  • maintaining energy levels
  • preventing cancer
  • promoting heart health.

The following medications have negative interactions with Vitamin B and Folate:

  • Anticonvulsant medications, such as Primidone, prevent the body from properly absorbing Folate.
  • Birth control pills typically limit the body’s ability to efficiently absorb Vitamin B and Folate and, therefore, require that a person takes more of these nutrients to ensure that she is getting the proper amounts of them.
  • Blood pressure medication, such as Hydralazine, increases the body’s Vitamin B and Folate requirements.
  • Isoniazid, an oral form of antibacterial medication used to treat tuberculosis, increases the body’s Vitamin B and Folate requirements.
  • Penicillamine, a medication used to treat metal poisoning and arthritis, increases the body’s Vitamin B and Folate requirements.
  • Sedative medications prevent the body from properly absorbing Vitamin B and Folate.

Negative Interactions Between Vitamin C and Other Medications

Vitamin C has many essential roles in maintaining our overall health by aiding:

  • collagen production (Collagen is a key part of healthy skin.)
  • maintenance of bones and blood vessel structures
  • metabolism
  • neurotransmitter production and function
  • overall energy.

The following medications have negative interactions with Vitamin C:

  • Anti-inflammatory medications, such as aspirin, can limit the body’s ability to effectively use Vitamin C.
  • Tetracyclin (defined above) reduces the body’s levels of Vitamin C.

Vitamin D and Other Medication Interactions

This vital nutrient is necessary for:

  • appropriate, healthy cell reproduction (i.e., after injury)
  • cancer prevention
  • healthy circulation
  • liver health
  • proper calcium absorption.

Some of the medications that can react poorly with Vitamin D include:

  • Laxatives slow down the body’s ability to absorb and use Vitamin D.
  • Sedatives, such as Glutethimide, deplete the body’s levels of Vitamin D.

Negative Interactions Between Vitamin E and Other Medications

Vitamin E is necessary to:

  • eliminating cancer-causing free radicals in the body
  • keeping the prostate healthy
  • maintaining a healthy metabolism
  • preventing heart disease.

Medications that typically have negative interactions with Vitamin E:

  • Dicumarol, a medication used to treat blood clotting disorders, severely limits the blood’s ability to clot when it interacts with Vitamin E.
  • Digoxin, a medication prescribed for a number of heart problems, can cause irregular heartbeats (arrhythmias) and dangerously high levels of calcium in the blood.


Linus Pauling Institute (n.d.). Micronutrient Information Center. Retrieved November 11, 2007, from the LPI Web site:

Nutrient Dynamics Inc. (n.d.). Drug-Nutrient Interaction. Retrieved November 11, 2007, from the Nutrient Dynamics Inc. Web site: