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Interactions

Interactions with Drugs

Vitamin C may increase adverse effects associated with acetaminophen.

Vitamin C may increase adverse effects associated with aluminum-containing antacids such as aluminum hydroxide (Maalox, Gaviscon).

Vitamin C may increase blood levels and adverse effects of aspirin, whereas aspirin may decrease blood levels of vitamin C.

The effects of vitamin C may be decreased by barbiturates including phenobarbital (Luminal, Donnatal), pentobarbital (Nembutal), or secobarbital (Seconal).

Vitamin C supplementation may decrease levels of the drug fluphenazine in the body.

Concomitant administration of high doses of vitamin C can reduce steady-state indinavir plasma concentrations.

There is limited case report evidence that high dose vitamin C may reduce side effects of levodopa therapy such as nausea or malcoordination.

Nicotine products such as cigarettes, cigars, chewing tobacco, or nicotine patches may decrease the effects of vitamin C.

Oral estrogens may decrease the effects of vitamin C in the body. When taken together, vitamin C may increase blood levels of ethinyl estradiol.

The effects of vitamin C may be decreased by tetracycline antibiotics such as doxycycline (Vibramycin), minocycline (Minocin), or tetracycline (Sumycin).

Vitamin C in high doses appears to interfere with the blood thinning effects of warfarin by lowering prothrombin time (PT), as noted in case reports in the 1970s. Complications have not been reported (such as increased blood clots).

Interactions with Herbs and Dietary Supplements

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.

Vitamin C may increase absorption of lutein vitamin supplements.

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

Attribution

This information is based on a systematic review edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com): Ethan Basch, MD (Memorial Sloan-Kettering Cancer Center); Catherine Ulbricht, PharmD (Massachusetts College of Pharmacy); Christine Ulbricht, PharmD (University of Massachusetts); Wendy Weissner, BA (Natural Standard Research Collaboration).

Bibliography

DISCLAIMER: Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

Akikusa JD, Garrick D, Nash MC: Scurvy: forgotten but not gone. J Paediatr Child Health 2003 Jan-Feb; 39(1): 75-7.

Anonymous. A randomized, placebo-controlled, clinical trial of high-dose supplementation with vitamins C and E and beta carotene for age-related cataract and vision loss. Arch Ophthalmol 2001; 119:1439-1452.

Cameron E, Pauling L. Supplemental ascorbate in the supportive treatment of cancer: reevaluation of prolongation of survival times in terminal human cancer. Proc Natl Acad Sci U S A. 1978 Sep;75(9):4538-42. No abstract available.

Casanueva E, Ripoll C, Tolentino M, et al. Vitamin C supplementation to prevent premature rupture of the chorioamniotic membranes: a randomized trial. Am J Clin Nutr 2005;81(4):859-863.

Doyle J, Verman HJ, Stevenson DK, et al. Does vitamin C cause hemolysis in premature newborn infants? Results of a multicenter double-blind, randomized, controlled trial. J Pediatr 1997; 130:103-109.

Engelhart MJ, Geerlings MI, Ruitenberg A, et al. Dietary intake of antioxidants and risk of Alzheimer disease. JAMA 2002;287(24):3223-3229.

Ehrlich M, Rao J, Pabby A, et al. Improvement in the appearance of wrinkles with topical transforming growth factor beta(1) and l-ascorbic acid. Dermatol Surg. 2006 May;32(5):618-25.

Ghosh SK, Ekpo EB, Shah IU et al: A double-blind placebo-controlled parallel trial of vitamin C treatment in elderly patients with hypertension. Gerontology 1994; 40:268-272.

Muran PJ. Mercury elimination with oral DMPS, DMSA, vitamin C, and glutathione: an observational clinical review. Altern Ther Health Med. 2006 May-Jun;12(3):70-5.

Nam CM, Oh KW, Lee KH, et al. Vitamin C intake and risk of ischemic heart disease in a population with a high prevalence of smoking. J Am Coll Nutr 2003;22(5):372-378.

Petersen EE, Magnani P. Efficacy and safety of vitamin C vaginal tablets in the treatment of non-specific vaginitis. A randomised, double blind, placebo-controlled study. Eur J Obstet Gynecol Reprod Biol 2004;117(1):70-75.

Ram FS, Rowe BH, Kaur B. Vitamin C supplementation for asthma. Cochrane Database Syst Rev 2004;(3):CD000993.

Steyn PS, Odendaal HJ, Schoeman J, et al. A randomised, double-blind placebo-controlled trial of ascorbic acid supplementation for the prevention of preterm labour. J Obstet Gynaecol 2003;23(2):150-155.

Taji Y, Morimoto T, Okada K, et al. Effects of intravenous ascorbic acid on erythropoiesis and quality of life in unselected hemodialysis patients. J Nephrol 2004;17(4):537-543.

Tousoulis D, Antoniades C, Tountas C, et al. Vitamin C affects thrombosis/ fibrinolysis system and reactive hyperemia in patients with type 2 diabetes and coronary artery disease. Diabetes Care 2003;26(10):2749-2753.

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.