What herbs and supplements can interact with vitamin C supplements?

Vitamin C in high doses appears to interfere with the blood-thinning effects of anticoagulants by lowering prothrombin time (PT).

Vitamin C may affect blood sugar levels. Caution is advised when using herbs or supplements that may also affect blood sugar. Blood glucose levels may require monitoring, and doses may need adjustment.

Vitamin C may affect blood pressure. Caution is advised in patients taking herbs or supplements that affect blood pressure.

When taken together, vitamin C may increase the absorption of iron in the gastrointestinal tract, although this effect appears to be variable and may not be clinically significant.

Large doses of vitamin C may interfere with the absorption and metabolism of vitamin B12.

Vitamin C may also interact with acerola, antacids, antibacterials, anticancer agents, antioxidants, antivirals, Cherokee rosehip, cholesterol-lowering agents, chromium, copper, diuretics, grape seed extract, grapefruit, hormonal agents, kidney-damaging agents, lutein, niacin, tobacco, sedatives, urine acidifying agents, and vitamin E.

You should read product labels, and discuss all therapies with a qualified healthcare provider. Natural Standard information does not constitute medical advice, diagnosis, or treatment.