Nutritional supplement (vitamin) –Ascorbic acid is necessary for collagen formation and tissue repair in the body and may be involved in some oxidation – reduction reactions . It is also involved in metabolism of phenylalanine , tyrosine , folic acid , norepinephrine , histamine , iron , and some drug enzyme systems ; utilization of carbohydrates ; synthesis of lipids , proteins , and carnitine ; immune function ; hydroxylation of serotonin ; and preservation of blood vessel integrity . In addition , ascorbic acid enhances the absorption of nonheme iron .
Deferoxamine adjunct (chronic iron overdose ) – Complex interaction ; vitamin C given orally in small doses (150 to 250 mg per day ) may improve the chelating action of deferoxamine and increase the amount of iron excreted.

Prevention and treatment of vitamin C deficiency . Deficiency of ascorbic acid may lead to scurvy. Requirements may be increased and /or supplementation may be necessary in the following persons or conditions : AIDS , alcoholism , burns , cancer , prolonged exposure to cold temperatures , prolonged fever , gastrectomy , chronic hemodialysis , hyperthyroidism , infant receiving unfortified formulas , continuing infection , intestinal diseases ( prolonged diarrhea , ileal resection ) , peptic ulcer , smokers , continuing stress , surgery , continuing trauma , tuberculosis , patients receiving TPN or undergoing rapid weight loss or in those with malnutrition , pregnancy , breast –feeding , chronic iron toxicity (treatment adjunct) , idiopathic methemoglobinemia (treatment adjunct)

Oxalate kidney stones ; Diarrhea (with oral doses greater than 1 gram per day ) ; Flushing or redness of skin ; Headache ; Mild increase in urination (with doses greater than 600 mg per day); Nausea or vomiting ; Stomach cramps.

Hypersensitivity to ascorbic or any component of the formulation.

Risk –benefit should be considered when the following medical problems exist : Diabetes mellitus ; G6PD deficiency ; Hemochromatosis ; Sideroblastic anemia ; Thalassemia ; Hyperoxaluria or oxalosis ; History of renal stones.

Large doses of ascorbic acid may lower urinary pH and cause renal tubular reabsorption of acidic medications with concurrent administration ; alkaline medications may exhibit decreased reabsorption . Doses of 10 grams or more a day of ascorbic acid have been reported to impair GI absorption of coumarin – or indandione – derivative anticoagulants . Concurrent use of cellulose sodium phosphate may result in metabolism of ascorbic acid to oxalate . Concurrent use of deferoxamine with ascorbic acid may enhance tissue iron toxicity , especially in the heart , causing cardiac decompensation ; therefore , this regimen should be used with caution in older patients ; the need for ascorbic acid supplementation should be completely documented by measurements of iron excretion before and after supplements , and the oral dose of ascorbic acid should be given an hour or two after the deferoxamine infusion has been initiated when adequate concentrations of deferoxamine have been achieved . Concurrent use with ascorbic acid , especially with chronic use or high doses , may interfere with the disulfiram – alcohol interaction . Aspirin decreases ascorbic acid levels . Ascorbic acid decreases fluphenazine levels.

The determination of plasma or serum ascorbic acid is recommended to determine ascorbic acid deficiency . The buffy coat levels of ascorbic acid are used to determine ascorbic acid stores . Monitor pH of urine when using as an acidifying agent.