Taking Calcium With Other Medications

by Jim Sliney, Jr.

Because of the way calcium is digested and absorbed, taking calcium at the same time as certain other medications may reduce, increase, or otherwise change the effectiveness of those medications. Listed below are some of the medications that calcium is known to interfere with. If you are taking one of these medications, talk with your doctor to learn about the right way to take your calcium supplement.

Calcium is known to interfere with—

  • Antibiotics. Calcium could interfere with the absorption of the antibiotic so the two should be taken at least one hour apart from each other. Of note, intravenous Rocephin/Ceftriaxon interacts dangerously with calcium, therefore calcium should be withheld for 48 hours prior to or after administration of this drug
  • Bisphosphonates. Bisphophonates are osteoporosis drugs like Fosamax, Didronel, Actonel, etc. Calcium should be taken at least 30 minutes after a dose of bisphosphonate
  • Calcipotriene/Dovonex. These are synthetic vitamin D derivatives. If taken with calcium, they can cause elevations in blood calcium
  • Thiazide diuretics (water pills, like hydrochlorothiazide). If taken with calcium, can cause elevations in blood calcium
  • Estrogens. Can also cause elevations in blood calcium, if taken together with calcium
  • Blood pressure medicines (like Digoxin, Diltiazem, and Verapamil). Taking these at the same time as your calcium may cause irregular heartbeat
  • Levothyroxine/Synthroid. Calcium can interfere with the absorption of medications for hypothyroidism. Calcium and levothyroxine should be taken at least 4 hours apart. For hypothyroidism patients one way to accomplish this is to take your levothyroxine in the middle of the night when you get up to use the bathroom
  • Betapace. Betapace is an anti-arrhythmia drug. Avoid taking calcium 2 hours before and 4 hours after taking this medication

These are just a few of the medicines that calcium may interfere with. For more information, visit the University of Maryland, WebMD, and NIH sites or contact your healthcare provider.

Cal-EZ has developed a printable Calcium Tip Sheet with a list of Do's and Don'ts for taking calcium and a list of medications that interact with calcium. And best of all, you can take it with you - the tip sheet is the size of a US dollar bill so you can easily keep it in your wallet or purse. We hope you find these tips useful and educational.

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