Corticosteroids are often prescribed to decrease inflammation and treat health conditions like ulcerative colitis or asthma. Examples of corticosteroids include prednisone, hydrocortisone, and dexamethasone.1
Steroids may decrease calcium absorption, affecting how well vitamin D is absorbed and used in the body. Some studies suggest low vitamin D levels are more common in people taking steroids, but other studies do not find this connection.14
5. Bile Acid Sequestrants
Bile acid sequestrants are medications prescribed to lower cholesterol and blood sugar levels. Examples include cholestyramine, colesevelam, and colestipol.5
Bile acid sequestrants bind bile acid (which helps break down fat) in the intestines and prevent it from entering the blood. This forces the liver to take cholesterol from the blood to make more bile acid, lowering cholesterol levels.6
The drug can also bind to other drugs, including vitamin D, in the stomach and intestines, reducing the body’s vitamin D levels.4
If you are taking a bile acid sequestrant and vitamin D, it’s best to take vitamin D at least four hours before the bile acid sequestrant.5
6. Digoxin
Lanoxin (digoxin) is a medication prescribed to treat heart conditions like atrial fibrillation and heart failure.
Taking high doses of vitamin D can increase your risk for hypercalcemia, where there is too much calcium in the blood. High calcium levels can increase your risk for abnormal heart rhythms (arrhythmias) if you also take digoxin.2
As long as you don’t exceed the tolerable upper level of for vitamin D, which is 4,000 International Units (IU) daily, the interaction risk is low.2
7. Diltiazem
Cardizem (diltiazem) is a medication prescribed to treat certain heart and blood vessel conditions.
The interaction between vitamin D and diltiazem is related to how both drugs affect calcium levels. High doses of vitamin D can increase your risk for hypercalcemia. High calcium levels can increase your risk for arrhythmias if you are also taking diltiazem.2
The interaction risk between diltiazem and vitamin D is low if taking vitamin D below the tolerable daily upper level.2
8. Mineral Oil
