Does vitamin D interact with other medications?
Yes. Steroid medications such as prednisone can interfere with vitamin D metabolism. If you take steroid drugs regularly, discuss vitamin D with your doctor.
The weight loss drug orlistat -- brand names include Xenical and Alli -- may cut absorption of vitamin D. So does the cholesterol-lowering drug cholestyramine (sold as Questran, LoCholest, and Prevalite). People taking these drugs should discuss vitamin intake with their doctors.