Interactions

Interactions with Drugs

Vitamin C in high doses may interfere with the blood-thinning effects of aspirin, anticoagulants such as warfarin(Coumadin®) or heparin, and anti-platelet drugs such as clopidogrel (Plavix®).

Vitamin C may affect blood sugar levels. Caution is advised when using medications that may also affect blood sugar. People taking insulin or drugs for diabetes by mouth should be monitored closely by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.

Vitamin C may affect blood pressure. Caution is advised in people taking agents that affect blood pressure.

Vitamin C may also interact with acetaminophen, acidifying agents, agents for Parkinson's disease, agents that affect the immune system, agents that increase urine flow, agents used for asthma, agents used for the heart, lungs, stomach or intestines, agents used for the teeth, eyes or the skin, agents used to regulate heart rate, aldose reductase inhibitors, antacids, antibiotics, anticancer drugs, aspirin, barbiturates, birth control taken by mouth, cholesterol-lowering agents, estrogens, fluphenazine, HIV medications, indinavir, kidney agents, levodopa, nicardipine, nicotine-containing products (such as cigarettes, cigars, chewing tobacco, or nicotine patches), progesterones, proton pump inhibitors (PPIs), and salicylates.

Interactions with Herbs and Dietary Supplements

Vitamin C in high doses may interfere with the blood-thinning effects of anticoagulant and anti-platelet herbs and supplements.

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 people taking herbs or supplements that affect blood pressure.

Vitamin C may also interact with acerola, acidifying herbs and supplements, aldose reductase inhibitors, antacids, antibacterials, anticancer herbs and supplements, antioxidants, antiretrovirals, Cherokee rosehip, cholesterol-lowering herbs and supplements, chromium, copper, grape seed extract, grapefruit, herbs and supplements for Parkinson's disease, herbs and supplements that affect the immune system, herbs and supplements that increase urine flow, herbs and supplements used for asthma, herbs and supplements used for birth control, herbs and supplements used for the heart, lungs, stomach or intestines, herbs and supplements used for the teeth, eyes or the skin, herbs and supplements used to regulate heart rate, hormonal herbs and supplements, iron, kidney herbs and supplements, lutein, niacin, phytoestrogens, phytoprogesterones, salicylates, tobacco, urine acidifying herbs and supplements, and vitamins B12 and E.

This evidence-based monograph was prepared by The Natural Standard Research Collaboration

www.naturalstandard.com