Interactions

Vitamin C might react with the following:

• Aluminum. Taking vitamin C can make you take in more aluminum from medicines that have aluminum, such as phosphate binders. This can be harmful for people with kidney conditions.
• Chemotherapy. There is worry that use of vitamin C and other antioxidants during chemotherapy might keep chemotherapy medicines from working well.
• Estrogen. Taking vitamin C with birth control pills or hormone replacement therapy might raise estrogen levels.
• Protease inhibitors. Use of vitamin C might keep these antiviral medicines from working as well as they should.
• Statins and niacin. People with high cholesterol might take these medicines. Taking vitamin C with statins and niacin could keep the medicines from working as well as expected.
• Iron. Vitamin C makes the body absorb more iron. Getting more iron can be harmful for people who have a condition that causes too much iron in the body, called hemochromatosis.
• Warfarin (Jantoven). High doses of vitamin C might lower the body's response to this blood-thinning medicine.