Interactions

Possible interactions include:

• Aluminum. Taking vitamin C can increase your absorption of aluminum from medications containing aluminum, such as phosphate binders. This can be harmful for people with kidney problems.
• Chemotherapy. There is concern that use of antioxidants, such as vitamin C, during chemotherapy might reduce the effect of chemotherapy drugs.
• Estrogen. Taking vitamin C with oral contraceptives or hormone replacement therapy might increase your estrogen levels.
• Protease inhibitors. Oral use of vitamin C might reduce the effect of these antiviral drugs.
• Statins and niacin. When taken with vitamin C, the effects of niacin and statins, which might benefit people with high cholesterol, could be reduced.
• Warfarin (Jantoven). High doses of vitamin C might reduce your response to this anticoagulant.