Few medications negatively interact with calcium supplements. Vitamin D and oral contraceptives increase the absorption of calcium. Although required for effective bisphosphonate treatment, calcium decreases the levels of bisphosphonates and thus calcium supplements (like all other drugs) must be taken two hours after the medication to avoid this problem. The combination of phenytoin (Dilantin® 1) and calcium can result in the decreased absorption of both agents. Iron supplements decrease calcium absorption.
To avoid contraindications, your physician/pharmacist should review your profile for the drugs listed below:
- Aluminum containing compounds
- Antibiotics
- Anticoagulants (ex. heparin, warfarin)
- Anitconvulsants (ex. phenobarbital, phenytoin, carbamazepine)
- Bisphosphonates (ex. aledronate, etidronate, risedronate)
- Calcium Channel Blockers (ex. nifedipine, verapamil, diltiazem)
- Cholesterol lowering agents
- Cyclosporine
- Digitalis glycosides
- Diuretics
- Glucocorticoids
- GnRH Antagonists
- Gonatropin - releasing agents
- Isoniazid
- Laxatives (over-night)
- Lithium
- Methotrexate
- Retinoic Acid
- Thyroid hormones

Learn about this "silent disease" and what you can do to improve your bone health.