Drug-Nutrient Interactions

What medications affect vitamin D?

The following medications impact the absorption, utilization, and/or activation of vitamin D:

• Anticonvulsant medications, including Dilantin, are used to control seizure activity in people with epilepsy and brain cancer, and those who have suffered head trauma through injury or stroke. These medications decrease the activity of vitamin D.
• Bile acid sequestrants (Cholestyramine, Colestipol) are a class of drugs used to lower cholesterol levels. These drugs may reduce the intestinal absorption of the fat-soluble nutrients, including vitamins A, D, E, and K.
• Cimetidine (Tagamet and Tagamet HB) prevents the release of hydrochloric acid into the stomach and is used to treat the symptoms associated with stomach and duodenal ulcers and acid reflux. This drug may reduce vitamin D activation by the liver.
• Hormone replacement therapy may increase blood levels of vitamin D.
• The corticosteroids are a family of anti-inflammatory drugs, including hydrocortisone and prednisone, that are commonly used in the treatment of autoimmune and inflammatory diseases, such as asthma, rheumatoid arthritis, and ulcerative colitis. These drugs reduce the activation of vitamin D.
• Heparin, an anticoagulant prescription medication used to prevent blood clots after surgery, may interfere with vitamin D activation.

Vitamin D impacts the following medications:

• Vitamin D may interfere with the effectiveness of calcium channel-blockers, a class of drugs used to treat chest pain, irregular heart beat, and high blood pressure.
• Taking supplemental vitamin D and calcium along with thiazide diurectics can cause blood levels of calcium to increase above normal levels.