Does Calcium Affect Antibiotics?

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Calcium is a necessary mineral for developing and maintaining strong teeth and bones, heart function, nerve activity and for proper blood clotting. Many conditions and diseases are treated with increased calcium intake. Always let your doctor know about any medications or supplements you take before starting a calcium supplement as mild to serious interactions can occur with some medications for blood pressure, high cholesterol, anti-seizure treatment and antibiotics.


The two major kinds of calcium compounds are calcium citrate and calcium carbonate, according to the Office of Dietary Supplements of the National Institutes of Health. Each compound type contains different amounts of the actual calcium element. Your stomach absorbs calcium carbonate best when taken with food, but calcium citrate is absorbed well with or without food. Dairy products, such as non-fat milk, cheese and yogurt have a high amount of calcium, and some green vegetables and other food types have smaller amounts. Many foods, such as cereals, some juices, breads, soy milk and bottled water are fortified with calcium.


Fluoroquinolones are a type of antibiotic used to treat bacterial infections in various parts of the body, such as the urinary tract, bone and joint infections, prostate, ear, some sexually transmitted diseases and bronchitis. Generic fluoroquinolones include ciprofloxacin, levofloxacin, moxifloxacin, norfloxacin and enoxacin. Prescription information from states that fluoroquinolones should be taken with a full glass of water; enoxacin and norfloxacin are best taken on an empty stomach; and ciprofloxacin may be taken with a meal containing dairy products or calcium-fortified juices, but not with dairy products alone.


Tetracyclines are antibiotics, such as doxycycline, tetracycline, democlocycline and minocycline, which are used to treat respiratory tract infections, skin, urinary tract and genital infections, acne, stomach ulcers and as an alternative treatment for Lyme disease. Tetracycline antibiotics should be taken on an empty stomach one hour before or two hours after any calcium intake. Calcium may interfere with the absorption of tetracycline antibiotics when consumed too close together.


To get the full benefit of antibiotics and to reduce your chances of developing antibiotic-resistant bacteria, take all antibiotics as prescribed by your doctor. This includes drinking plenty of water and avoiding supplements, such as calcium, which can prohibit some antibiotics from adequate absorption. Some types of calcium supplements can render antibiotics ineffective. Talk to your doctor or pharmacist about the best time to take your medication and calcium to get the most benefit.