Brand name: Ascor
Drug class: Vitamin C
ATC class: A11GA01
VA class: VT400
Chemical name: l-ascorbic acid
CAS number: 50-81-7

Medically reviewed by Drugs.com on Apr 3, 2024. Written by ASHP.

Introduction

An essential water-soluble vitamin; ascorbic acid is the in vivo form of vitamin C.¹⁰⁹

Uses for Ascorbic Acid

Scurvy

Prevention and treatment of scurvy.^a

Dietary Requirements

Adequate intake needed to prevent scurvy and provide antioxidant protection.¹⁰⁹

Adequate vitamin C intake can be accomplished through consumption of foodstuffs.¹⁰⁹ Citrus fruits, tomatoes, and potatoes are the major contributors of vitamin C in the diet of US adults and children.¹⁰⁹

Recommended Dietary Allowances (RDA) in adults based on near maximal neutrophil concentrations with minimal urinary excretion of ascorbate.¹⁰⁹

Requirements slightly lower in women than men based on water-soluble nature of the vitamin and the larger lean body mass and total body water in males relative to females.¹⁰⁹

Adequate intake (AI) established for infants ≤6 months of age based on observed mean vitamin C intake of infants fed principally human milk; AI for infants 7–12 months of age based on vitamin C intake from human milk and solid food.¹⁰⁹

RDA for children 1–18 years of age based on data in adults.¹⁰⁹

Macular Degeneration

Suggested as a component of high-dose antioxidant supplements with zinc to reduce risk of developing advanced age-related macular degeneration^{† [off-label]} in high-risk patients (i.e., those with intermediate stage age-related macular degeneration or advanced stage macular degeneration in only one eye).^{111 112}

Respiratory Infections

Large doses have been advocated for lessening severity of and for preventing the common cold^{† [off-label]}.^a Routine supplementation modestly decreases duration of symptoms; also appears to decrease incidence in individuals under heavy physical stress but not in the overall population.^{202 203 211} No consistent effect on duration or severity of symptoms when initiated following symptom onset.^{202 211}

Limited study data available regarding effects in the prevention or treatment of pneumonia^{† [off-label]}; available studies were conducted under specific circumstances and may not be applicable to the general population.^{202 203}

Studies required to establish efficacy of adjunctive ascorbic acid therapy in the treatment of severe viral respiratory infections^{† [off-label]}.²⁰⁶

Sepsis

High-dose IV ascorbic acid has been evaluated in patients with sepsis^{† [off-label]};^{204 208 209 210} efficacy remains to be established.^{209 210 212 213}

Meta-analysis of several small studies suggested beneficial effects from adjunctive IV ascorbic acid in patients with sepsis, but primary efficacy end points were not improved in 2 subsequent multicenter, randomized studies (CITRIS-ALI, VITAMINS).^{208 209 210} Additional studies under way.^{204 213}

Methemoglobinemia

Has been used in the treatment of idiopathic methemoglobinemia^†.^a

Related/similar drugs

acetylcysteine, biotin, multivitamin, Vitamin C, Dextrose, niacin, Phospha 250 Neutral

Ascorbic Acid Dosage and Administration

Administration

Usually administered orally.^a May be administered by IM, IV, or sub-Q injection when oral administration is not feasible or when malabsorption is suspected.^a

Parenteral Administration

Preferred parenteral method of administration is IM.^a

Pressure may build within the vial during storage.^b Exercise care when withdrawing a dose and/or insert a vent needle (e.g., empty sterile syringe) into the vial to release the pressure.^b

IV Administration

Dilution

For solution and drug compatibility, see Compatibility under Stability.

Dilute with large volume of compatible parenteral fluid to minimize adverse reactions.^b Avoid rapid infusion.^b

Dosage

Available as ascorbic acid, calcium ascorbate, and sodium ascorbate; dosage expressed in terms of ascorbic acid.^{b d}

Pediatric Patients

Scurvy

Treatment

Oral or IV

100–300 mg daily for 1 month or until full recovery.^{a c}

Dietary and Replacement Requirements

Oral

Infants ≤6 months of age: Recommended AI is 40 mg (about 6 mg/kg) daily.¹⁰⁹

Infants 7–12 months of age: Recommended AI is 50 mg (about 6 mg/kg) daily.¹⁰⁹

Children 1–3 years of age: RDA is 15 mg daily.¹⁰⁹

Children 4–8 years of age: RDA is 25 mg daily.¹⁰⁹

Children 9–13 years of age: RDA is 45 mg daily.¹⁰⁹

Boys 14–18 years of age: RDA is 75 mg daily.¹⁰⁹

Girls 14–18 years of age: RDA is 65 mg daily.¹⁰⁹

Adults

Scurvy

Treatment

Oral or IV

300 mg–1 g daily for 1 month or until full recovery.^{b c}

Dietary and Replacement Requirements

Oral

Men ≥19 years of age: RDA is 90 mg daily.¹⁰⁹

Women ≥19 years of age: RDA is 75 mg daily.¹⁰⁹

Macular Degeneration†

Oral

500 mg in combination with beta carotene 15 mg, vitamin E 400 units, and zinc (as zinc oxide) 80 mg, with copper (as cupric oxide) 2 mg (to prevent anemia) daily has been used.^{111 112}

Respiratory Infections†

Common Cold†

Oral

1–3 g or greater per day has been recommended for prevention and treatment.^a

Idiopathic Methemoglobinemia†

Oral

300–600 mg daily in divided doses has been used.^a

Special Populations

Pregnant Women

RDA for pregnant women 14–18 years of age is 80 mg daily.¹⁰⁹

RDA for pregnant women 19–50 years of age is 85 mg daily.¹⁰⁹

Requirements increased in pregnant women to ensure transfer of adequate amounts of the vitamin to the fetus.¹⁰⁹

Lactating Women

RDA for lactating women 14–18 or 19–50 years of age is 115 or 120 mg daily, respectively.¹⁰⁹

Requirements increased in lactating women to ensure adequate concentration of the vitamin in milk.¹⁰⁹

Smokers

RDA increased by 35 mg daily.¹⁰⁹

Smoking increases oxidative stress and metabolic turnover of vitamin C.¹⁰⁹

Cautions for Ascorbic Acid

Contraindications

• Manufacturer states no known contraindications.^b

Warnings/Precautions

General Precautions

Sodium Content

Each 1 gram of sodium ascorbate contains approximately 5 mEq of sodium; consider sodium content in patients on sodium-restricted diets.^a

Kidney Stone Formation

Kidney stone (renal calculus) formation reported in individuals with renal disease receiving large dosages of ascorbic acid; excess ascorbic acid intake not associated with kidney stone formation in healthy individuals.¹⁰⁹

Aluminum Content

Some ascorbic acid injection preparations contain aluminum that may be toxic.^b Aluminum may reach toxic levels with prolonged parenteral administration if kidney function is impaired.^b Premature neonates are particularly at risk because their kidneys are immature, and they require large amounts of calcium and phosphate solutions, which contain aluminum.^b

Research indicates that patients with impaired kidney function, including premature neonates, who receive parenteral levels of aluminum >4–5 mcg/kg daily accumulate aluminum at levels associated with CNS and bone toxicity.^b Tissue loading may occur at even lower rates of administration.^b

Specific Populations

Pregnancy

Category C.^b

Lactation

Distributed into milk.^a Caution if parenteral preparation is used in nursing women.^b

Common Adverse Effects

Relatively nontoxic; nausea, vomiting, heartburn, fatigue, flushing, headache, insomnia, sleepiness, and other GI disturbances (diarrhea, transient colic, abdominal cramps, flatulent distention) reported.^a

Drug Interactions

Laboratory Tests

Interferes with numerous laboratory tests based on oxidation-reduction reactions.^a Degree of interference depends on several factors (e.g., ascorbic acid concentration, resulting pH, specific reagents).^a Consult specialized references.^a

Specific Drugs and Laboratory Tests

Ascorbic Acid Pharmacokinetics

Absorption

Bioavailability

Readily absorbed by an active process that may be limited after very large doses.^a

Distribution

Extent

Widely distributed in body tissues.^a

Crosses the placenta; cord blood concentration 2–4 times maternal blood concentrations.^a Distributed into human milk.^a

Plasma Protein Binding

About 25%.^a

Elimination

Metabolism

Reversibly oxidized to dehydroascorbic acid.^a

Elimination Route

Excreted in urine. ^a

Removed by hemodialysis.^a

Stability

Storage

Oral

Capsules and Tablets

Cool dry place.^d

Parenteral

Solution

Store in carton until time of use at room temperature (≤25°C).^b Protect from light. ^b

Compatibility

Parenteral

Solution CompatibilityHID

Drug Compatibility

Actions

• An essential water-soluble vitamin present in fresh fruits and vegetables.^a Vitamin C refers to both ascorbic acid and dehydroascorbic acid (DHA); both compounds exhibit antiscorbutic activity.¹⁰⁹

• An antioxidant and a cofactor in enzymatic and metabolic processes.¹⁰⁹

• Required for collagen formation and tissue repair.^b

Advice to Patients

• Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs as well as any concomitant illnesses.^a

• Importance of proper dietary habits, including taking appropriate AI or RDA of vitamin C.^a

• Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.^a

• Importance of informing patients of other important precautionary information.^a (See Cautions.)

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

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