Doxycycline & Calcium

When taking certain prescription medications, you may need to change your intake of vitamins, minerals or other supplements you usually consume to avoid negative interactions or side effects. Doxycycline is a drug that interacts with multiple substances, including calcium. Talk with your doctor if she prescribes you doxycycline about whether you need to change your calcium intake while on the medication.

Doxycycline is the generic name for the brand-name drug also known as Periostat, Vibramycin or Adoxa. It is a tetracycline antibiotic that helps the body fight bacterial infections. It may also be used to help treat acne and bumps caused by rosacea, says Drugs.com. This drug should be taken with a full glass of water, and you should drink adequate amounts of fluid while on doxycycline. Depending on the brand you get, you may have to take it with or without food. Talk with your doctor and pharmacist about the best way to take the medicine. Do not use this medication if you are pregnant or breastfeeding as it is not safe for the baby.

According to the National Institutes of Health Office of Dietary Supplements, calcium is necessary for multiple bodily functions, including nerve transmission, muscle contraction, intracellular signaling and proper vascular functioning. It is the mineral most commonly found in the body and helps maintain strong bones and teeth. Adults between the ages of 19 and 50 need 1,000 milligrams daily. Pregnant and lactating women should get 1,300 milligrams daily, says the Office of Dietary Supplements. Women over the age of 70 should consume 1,200 milligrams daily. Dietary sources include yogurt, fortified orange juice, cheese, milk, tofu, salmon and almonds.

Though it is a commonly used supplement, some medications can interact with calcium, including antibiotics like calcium. According to the University of Maryland Medical Center, calcium can interfere with absorption of doxycycline, so it is best to take these supplements two to four hours before or after taking the medicine. It is OK to eat foods containing calcium while taking this antibiotic.

If you are prescribed doxycycline, talk with your doctor about all other medications and supplements you are taking to avoid any adverse interactions. When taking calcium supplements, take only 500 milligrams at one time as the body cannot absorb more than that at once. Do not take more calcium than is recommended, as an excess can cause side effects like constipation, loss of appetite and kidney toxicity.