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Supplements That Should not be Mixed.....

Numerous individuals consume various dietary aids to support their health or enhance their overall wellness. These can include a variety of nutrients such as vitamins and minerals, herbal preparations, and beneficial bacteria known as probiotics. Some may opt for a mix of these dietary aids to maximize their health benefits. However, caution should be exercised, as specific blends can be harmful. These health supplements have the potential to cross-react, not just amongst themselves but also with any prescription drugs one might be using. Therefore, it is crucial to be informed about the possible reactions that can occur with supplement use.

Dietary Additive Interactions to Consider

While dietary additives can be beneficial for health, it's important to recognize they can also pose risks. At times, certain ingredients found in these additives might interfere with laboratory tests or lead to complications during medical procedures. The dangers associated with consuming multiple nutritional supplements simultaneously may be greater than with a singular supplement. Prior to combining them, it is advisable to consult a healthcare professional, especially regarding the following additive combinations, and to understand any necessary precautions if you are consuming both.

Calcium and Magnesium

Magnesium, an essential mineral, plays a pivotal role in over hundreds of enzymatic reactions in your body, crucial for muscle and nerve function, stabilizing blood sugar levels, and managing blood pressure. Green leafy vegetables, beans, nuts, seeds, and whole grains are natural sources of magnesium, and it's also available in supplement form; however, its supplementation may not be recommended in every instance.

Deficiencies in magnesium can contribute to conditions like heart disease, diabetes, and brittle bones. While rare, magnesium levels drop more frequently in certain populations, including:

  • Individuals with alcohol dependency

  • Those enduring gastrointestinal conditions or surgeries impacting nutrient absorption

  • Individuals with type 2 diabetes

  • Elderly adults

Calcium plays an indispensable role in bolstering bone health, predominantly found in dairy products like milk, cheese, and yogurt. In the United States, many adults do not consume sufficient calcium, with a deficiency rate of 30% among men and 60% among women. To bridge this nutritional gap, a supplement may be recommended. Insufficient calcium intake is associated with reduced bone density and the potential development of osteoporosis.

High doses of calcium supplementation (exceeding 2600mg daily) can impede magnesium absorption. It is suggested that individuals at high risk for magnesium deficiency and taking calcium supplements should take calcium at nighttime rather than with meals. Eating calcium with meals could adversely influence the absorption of dietary magnesium.

Vitamin C and Copper

Vitamin C is known for its role in collagen synthesis, which is vital for wound healing. People might take vitamin C for various reasons, including fighting infections, alleviating post-surgical pain, or managing blood pressure.

Copper, a key mineral, is involved in energy production and forming the connective tissues providing structure to your body. Supplementation with copper may be considered by those with cardiovascular disease because it has been indicated to alter blood lipid profiles, potentially reducing atherosclerotic cardiovascular disease risk. Moreover, those with Alzheimer's disease might use copper supplements, noted for copper deficiencies in such conditions.

It has been found that high doses of vitamin C (in excess of 1,500mg) may lead to a reduction in copper absorption, especially among individuals with already low copper intake.

Iron and Green Tea

Iron, an integral mineral, is a part of hemoglobin within red blood cells that transports oxygen from the lungs to the body's tissues. Iron supplementation is often advised for individuals with iron-deficiency anemia, certain types of cancer, some gastrointestinal disorders, and during pregnancy.

Green tea, appreciated for its health benefits, is consumed as a beverage or in extract form to enhance mental alertness, aid gastrointestinal discomfort, and as a preventive measure against various diseases.

However, the concurrent intake of green tea and iron could diminish the mineral's absorption. While this may not be critical for most, staggering the consumption times for those taking both could be beneficial.

Reactions Between Supplements and Medications

Certain dietary supplements can influence the absorption, metabolism, or excretion of medicines, potentially altering the drug's effectiveness. This interaction might result in either an overdose or underdose of the essential medication. Below are several vitamins and supplements and the medications they may interfere with.


Ashwagandha, a traditional herb used as an adaptogen, is claimed to bolster the body's resistance to stress and improve sleep quality. Potential medication interactions with ashwagandha include:

  • Diabetes medication, where ashwagandha could lead to hypoglycemia when taken with blood sugar-lowering drugs.

  • Blood pressure drugs, as ashwagandha might lower blood pressure too much when paired with such medication.

  • Immunosuppressants, considering ashwagandha might stimulate the immune system or lessen the effectiveness of drugs like cyclophosphamide used in cancer treatment.


With its numerous health roles, zinc could interfere with:

  • Antibiotics, particularly quinolone or tetracycline antibiotics, could have blocked absorption when taken with zinc.

  • Penicillamine, a drug used for rheumatoid arthritis, could be less effective when zinc is taken concurrently.


As a sleep regulator, melatonin supplementation could interact with:

  • Blood thinners, leading to increased bleeding risks when taken with drugs like warfarin.

  • Anticonvulsants, where melatonin might reduce drug effectiveness or increase seizure frequency in predisposed individuals.

St. John's Wort

Commonly used for depression, St. John's wort can have serious interactions with:

  • Certain antidepressants, possibly causing dangerous serotonin levels.

  • Various drugs, including birth control, drugs preventing organ transplant rejection, heart failure medication, pain medication, certain HIV and cancer drugs, and blood thinners.

Seeking Guidance from a Healthcare Provider

Should adverse effects emerge from supplement use, promptly consult a healthcare professional. These effects could include allergic reactions, breathing difficulties, fainting, chest pain, gastrointestinal issues, abnormal bleeding, fatigue, appetite loss, jaundice, severe pain, or changes in bodily waste color.

It's especially crucial to discuss supplement and medication combinations with a healthcare provider before starting any new regimen. This is particularly vital for pregnant or breastfeeding individuals, children, or anyone soon undergoing surgery, as supplements might have adverse interactions with anesthetics or other surgical drugs.

In summary, the convenience of purchasing supplements must be weighed against the potential for adverse interactions, particularly if you're combining them or taking them alongside other medications. Always consult with a healthcare provider to determine what is safe and appropriate for your specific health needs.

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