Usage
- L-ascorbic acid, commonly known as Vitamin C, is primarily used to prevent and treat vitamin C deficiency (scurvy). It’s also used to improve iron absorption from plant-based foods and promote wound healing. Some studies suggest potential benefits for various health conditions, including supporting the immune system and acting as an antioxidant. It’s considered a vitamin and an antioxidant agent by pharmacological classifications.
- The primary mechanism of action involves its role as a cofactor in various enzymatic reactions, including collagen synthesis, carnitine biosynthesis, and catecholamine synthesis. It also acts as an antioxidant, scavenging free radicals and protecting cells from oxidative damage.
Alternate Names
- Vitamin C
- Ascorbic acid
- L-ascorbate
How It Works
- Pharmacodynamics: Vitamin C is crucial for collagen synthesis, supporting the structural integrity of blood vessels, skin, and other tissues. It also plays a role in immune function, wound healing, and iron absorption. Its antioxidant properties help protect cells from damage caused by free radicals.
- Pharmacokinetics: Vitamin C is absorbed in the small intestine via active transport and simple diffusion. Absorption efficiency decreases with increasing doses. It’s widely distributed throughout the body, with highest concentrations in the pituitary and adrenal glands, brain, leukocytes, and eyes. It’s primarily eliminated through renal excretion, with metabolism playing a minor role.
Dosage
Standard Dosage
Adults:
- Dietary Supplement: 75-90 mg daily (oral). Higher doses (up to 2,000 mg/day) may be used therapeutically for certain conditions, but it’s essential to consult a healthcare professional for appropriate dosing.
- Scurvy Treatment: 100-500 mg daily (oral, IM, IV, or SC) for a minimum of two weeks, adjusted based on individual response.
Children:
- Dietary Supplement: Dosage varies depending on age, starting at 40 mg/day for infants and increasing to 45-75 mg/day for adolescents. Specific age-based recommendations should be followed.
- Scurvy Treatment: Dosages should be determined by a pediatrician based on the child’s weight and severity of the deficiency.
Special Cases:
- Elderly Patients: May require higher doses due to potential decreased absorption.
- Patients with Renal Impairment: Dose adjustments may be needed based on the degree of impairment, as vitamin C is renally cleared.
- Patients with Hepatic Dysfunction: No specific dose adjustments are typically necessary, as the liver doesn’t play a primary role in vitamin C metabolism.
- Patients with Comorbid Conditions: Consult a healthcare professional to tailor the dose based on individual needs and potential drug interactions.
Clinical Use Cases
- While vitamin C deficiency may occur in critical care settings, there aren’t standard dosing protocols for intubation, surgical procedures, mechanical ventilation, or ICU use. Dosing will depend on the individual’s clinical condition and nutritional status.
- In emergency situations, vitamin C might be administered as part of supportive care, but its use is not standard practice for specific emergencies like status epilepticus or cardiac arrest.
Dosage Adjustments
- Dosage adjustments are crucial for patients with renal impairment. Dialysis patients may require supplementation due to vitamin C loss during dialysis.
Side Effects
Common Side Effects
- Diarrhea
- Nausea
- Heartburn
- Abdominal cramps
- Headache
- Fatigue
Rare but Serious Side Effects
- Kidney stones (with high doses)
- Hemolysis (in individuals with G6PD deficiency)
Long-Term Effects
- Potential for kidney stones with chronic high-dose intake
Adverse Drug Reactions (ADR)
- Allergic reactions (rare)
Contraindications
- Hypersensitivity to ascorbic acid
- History of oxalate kidney stones (high doses should be avoided)
- G6PD deficiency (high doses should be avoided)
- Certain blood disorders (e.g., thalassemia, hemochromatosis) require careful monitoring
Drug Interactions
- Aspirin/NSAIDs: May decrease vitamin C levels
- Acetaminophen: High doses of vitamin C may increase acetaminophen levels
- Aluminum-containing antacids: Vitamin C may increase aluminum absorption
- Warfarin: May interfere with warfarin’s anticoagulant effects
- Iron: Vitamin C enhances iron absorption
- Oral contraceptives: May increase estrogen levels
- Certain antibiotics: May decrease the effectiveness of some antibiotics (e.g., erythromycin, kanamycin, tetracycline)
Pregnancy and Breastfeeding
- Pregnancy: Generally considered safe at recommended doses. High doses should be avoided, as they may lead to rebound scurvy in the infant after birth.
- Breastfeeding: Vitamin C passes into breast milk. Use with caution and adhere to recommended intake levels.
Drug Profile Summary
- Mechanism of Action: Cofactor in various enzymatic reactions; antioxidant
- Side Effects: Diarrhea, nausea, heartburn, abdominal cramps, headache
- Contraindications: Hypersensitivity, oxalate kidney stones, G6PD deficiency
- Drug Interactions: Aspirin, acetaminophen, antacids, warfarin, iron, oral contraceptives, some antibiotics
- Pregnancy & Breastfeeding: Safe at recommended doses; avoid high doses
- Dosage: Adults: 75-90 mg/day; children: age-dependent; higher doses for scurvy treatment
- Monitoring Parameters: Renal function (in high-dose or chronic use)
Popular Combinations
- Often combined with other vitamins and minerals in multivitamin formulations.
- Combined with bioflavonoids in some supplements.
Precautions
- General Precautions: Patients with a history of kidney stones, diabetes, or G6PD deficiency should exercise caution and consult a healthcare professional before taking high doses or chronic supplementation.
- Specific Populations: Pregnant and breastfeeding women should follow recommended intake levels.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for L Ascorbic acid?
A: 75-90 mg/day for adults, with pediatric doses varying by age. Higher doses are used for scurvy treatment and other specific medical conditions under the guidance of a healthcare professional.
Q2: What are the primary uses of L Ascorbic acid?
A: Preventing and treating vitamin C deficiency, aiding iron absorption, and promoting wound healing.
Q3: Can I take L Ascorbic acid if I’m pregnant or breastfeeding?
A: Yes, at recommended dosages. Consult your doctor before taking high doses.
Q4: What are the common side effects of L Ascorbic acid?
A: Diarrhea, nausea, heartburn, abdominal cramps, and headache.
Q5: Does L Ascorbic acid interact with any medications?
A: Yes, it can interact with aspirin, acetaminophen, antacids, warfarin, iron, oral contraceptives, and certain antibiotics. Consult your doctor about potential interactions.
Q6: Are there any contraindications for L Ascorbic acid use?
A: Yes, contraindications include hypersensitivity to ascorbic acid, history of oxalate kidney stones, G6PD deficiency, and certain blood disorders.
Q7: What is the role of L Ascorbic acid as an antioxidant?
A: It acts as a free radical scavenger, protecting cells from oxidative damage.
Q8: How is L Ascorbic acid absorbed and eliminated from the body?
A: Absorbed in the small intestine and eliminated primarily through renal excretion.
Q9: Can L Ascorbic Acid be administered intravenously?
A: Yes, for specific clinical situations like severe deficiency or malabsorption, intravenous administration may be employed. However, this should only be performed under the supervision of a medical professional.
Q10: How should vitamin C be stored?
A: Vitamin C is easily oxidized and degrades with exposure to light and air. Store in a cool, dark, and dry place in airtight containers.
