Ascorbic Acid

Ascorbic Acid: What is it and how does it work in the body?

• Ascorbic acid (AA), or Vitamin C, acts as a biological antioxidant.

• This works as a substance that prevents the oxidation of important biomolecules such as fatty acids, DNA, or proteins from a reactive oxygen species.

• It is found in fruits and vegetables, especially strawberries, citrus, kiwi, brussels sprouts, and cauliflower.

What is it used for and at what dosage?

• Ascorbic acid is utilized for the prevention and treatment of scurvy, macular degeneration, respiratory infections, and idiopathic methemoglobinemia.

• This literature review will examine the efficacy of ascorbic acid as a supplementation.

• The recommended dietary allowance for men greater than 19 years of age is 90 mg daily and for women greater than 19 years of age is 75 mg daily

Evidence for or against its different uses:

• There are mixed studies that support the efficacy of ascorbic acid supplementation in improving glycemic outcomes.

• A recent study assessed 31 individuals with type 2 diabetes and its effect on postprandial glucose responses underfree-living conditions demonstrated improved postprandial and 24-h hyper-glycemia and decreased blood pressure after 4 months of supplementation compared to placebo.

Safety concerns, side effects, and precautions:

• If the supplement is paired with sodium (sodium ascorbate), this contains approximately 5 mEq of sodium and must be taken with caution in sodium-restricted diet patients.

• Renal calculi have also been reported in patients with renal disease taking large doses of ascorbic acid; however, no kidney stone formation was observed in healthy individuals even with excess AA intake. There are also some Ascorbic Acid injections that contain aluminum, therefore premature neonates with immature kidneys or individuals with renal disease must be treated with caution.

Interactions with medications:

• Ascorbic acid interacts with aspirin by increased urinary excretion of ascorbic acid and decreased excretion of aspirin with concomitant administration.

• In addition, taking fluphenazine with AA can decrease fluphenazine concentrations. It can increase GI absorption of iron. Finally, there is a possibility that it can decrease the anticoagulant effect although not all investigators observed this effect.

Key Web Sources

• Henry J, Benzie IFF. Advances in food and nutrition research, vol. Seventy One. Academic

  Press; 2014.

• American Society of Health-Systems Pharmacists. Ascorbic acid. In: Snow EK, editor. AHFS drug information 2020. Bethesda, MD: American Society of Health-Systems

  Pharmacists; 2020.

• Hemilä H, Louhiala P. Vitamin C for preventing and treating pneumonia. Cochrane Database

  Syst Rev. 2013;(CD005532)

• Age-Related Eye Disease Study Research Group. A randomized, placebocontrolled, clinical

  trial of high-dose supplementation with vitamins C and E, beta carotene, and zinc for age-

  related macular degeneration and vision loss. Arch Ophthalmol. 2001;119:1417–36.

• Committee on the Scientific Evaluation of Dietary Reference Intakes of the Food and

  Nutrition Board, Institute of Medicine, National Academy of Sciences. Dietary reference intakes for vitamin C, vitamin E, selenium, and carotenoids. Washington, DC: National

  Academy Press; 2000.

• Mason SA, Rasmussen B, van Loon LJC, Salmon J, Wadley GD. Ascorbic acid supplementation improves postprandial glycaemic control and blood pressure in individuals with type 2

  diabetes: findings of a randomized cross-over trial. Diabetes Obes Metab.

• Luitpold Pharmaceuticals, Inc. Ascorbic acid injection prescribing information. Shirley,

  NY; 2000.