Introduction
Vitamin C, also known as ascorbic acid, is a water-soluble vitamin essential for various physiological functions. It is a potent antioxidant that helps protect cells from damage by free radicals. Vitamin C is also crucial for the synthesis of collagen, a protein necessary for the health of skin, blood vessels, bones, and connective tissues.
Uses
Vitamin C is used for:
- Preventing and treating scurvy, a disease caused by Vitamin C deficiency.
- Supporting immune system function and enhancing the body's ability to fight infections.
- Promoting wound healing and maintaining healthy skin.
- Reducing the severity and duration of common colds, although evidence is mixed.
- As an adjunct in the treatment of various conditions related to oxidative stress, such as cardiovascular disease and cancer.
| Brand Name | Vitamin C [Ascorbic acid] |
|---|---|
| Type | |
| Weight | |
| Generic | Vitamin C [Ascorbic acid] |
| Manufacturer | |
| Available in | English বাংলা |
Mechanism of Action
Vitamin C acts primarily as an antioxidant, neutralizing free radicals and reducing oxidative stress. It also plays a vital role in collagen synthesis by facilitating the hydroxylation of proline and lysine residues in collagen, which is essential for maintaining the structural integrity of connective tissues.
How Long Does It Take to Work?
Vitamin C starts to work almost immediately after ingestion, with blood levels peaking within 1-2 hours. The effects of Vitamin C on the body, such as improved immune function and enhanced collagen synthesis, become more apparent with consistent use over time.
Absorption
Vitamin C is absorbed primarily in the small intestine through active transport. The absorption efficiency decreases as the dose increases. At lower doses, absorption is high, but it decreases at higher doses due to saturation of the transport mechanisms.
Route of Elimination
Vitamin C is eliminated primarily through the kidneys. It is excreted in the urine as ascorbate and its metabolites. Excessive amounts of Vitamin C that are not used by the body are rapidly excreted.
Dosage
Oral tablet administration:- For the prevention of scurvy: 1 tablet daily
- For the treatment of scurvy: 1-2 tablets daily; but dose may be increased depending on the severity of the condition.
- For the reduction of risk of stroke in the elderly: 1-2 tablets daily.
- In other cases: 1 tablet daily or as directed by the physician.
- Maximum safe dose is 2000 mg daily in divided doses.
Parenteral administration:
- Vitamin C is usually administered orally. When oral administration is not feasible or when malabsorption is suspected, the drug may be administered IM, IV, or subcutaneously. When given parenterally, utilization of the vitamin reportedly is best after IM administration and that is the preferred parenteral route.
- For intravenous injection, dilution into a large volume parenteral such as Normal Saline, Water for Injection, or Glucose is recommended to minimize the adverse reactions associated with intravenous injection.
- The average protective dose of vitamin C for adults is 70 to 150 mg daily. In the presence of scurvy, doses of 300 mg to 1 g daily are recommended. However, as much as 6 g has been administered parenterally to normal adults without evidence of toxicity.
- To enhance wound healing, doses of 300 to 500 mg daily for a week or ten days both preoperatively and postoperatively are generally considered adequate, although considerably larger amounts have been recommended. In the treatment of burns, doses are governed by the extent of tissue injury. For severe burns, daily doses of 1 to 2 g are recommended. In other conditions in which the need for vitamin C is increased, three to five times the daily optimum allowances appear to be adequate.
- Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever the solution and container permit.
The recommended daily allowance (RDA) for Vitamin C varies based on age, sex, and life stage. For adults, the RDA is typically:
- Men: 90 mg per day
- Women: 75 mg per day
Administration
Vitamin C can be administered orally in the form of tablets, capsules, powders, or liquids. It is also available as an intravenous formulation for specific medical conditions. The method of administration depends on the intended use and patient needs.
Side Effects
Common side effects of Vitamin C include:
- Gastrointestinal discomfort, such as nausea or diarrhea, particularly with high doses.
- Abdominal cramps or bloating.
- Kidney stones, especially with chronic high-dose use.
Toxicity
Vitamin C toxicity is rare due to its water-soluble nature and efficient renal excretion. High doses (above 2,000 mg per day) may lead to gastrointestinal issues and an increased risk of kidney stones. Symptoms of toxicity include nausea, diarrhea, and abdominal pain.
Precautions
Precautions include:
- Monitor intake to avoid excessive doses, especially in individuals with a history of kidney stones or renal impairment.
- Consult a healthcare provider before starting high-dose Vitamin C, particularly during pregnancy or lactation.
Interaction
Vitamin C can interact with various medications and conditions:
- It may enhance the absorption of iron from supplements and dietary sources.
- It can affect the absorption and effectiveness of certain medications, such as chemotherapy agents and anticoagulants.
Disease Interaction
Use Vitamin C with caution in:
- Individuals with a history of kidney stones or renal dysfunction.
- Patients with certain chronic diseases that may affect Vitamin C metabolism or require adjusted dosing.
Drug Interaction
Vitamin C may interact with:
- Anticoagulants, potentially affecting their effectiveness.
- Certain chemotherapy drugs, potentially altering their efficacy.
Food Interactions
Vitamin C is commonly found in fruits and vegetables, and dietary intake can affect its supplementation. No specific food interactions are noted, but high-dose Vitamin C should be managed with consideration of overall dietary intake to avoid excessive intake.
Pregnancy Use
Vitamin C is considered safe during pregnancy when used within recommended doses. The RDA for pregnant women is typically 85 mg per day. Consult a healthcare provider for appropriate dosage and to avoid potential interactions with prenatal vitamins or other supplements.
Lactation Use
Vitamin C is also considered safe during lactation with an RDA of 120 mg per day. Adequate Vitamin C is important for both the mother and infant, and supplementation should be discussed with a healthcare provider to ensure appropriate dosing.
Acute Overdose
In case of acute overdose, symptoms may include severe gastrointestinal upset, including nausea, vomiting, and diarrhea. If high doses are consumed, seek medical attention to manage symptoms and prevent complications.
Contraindication
Vitamin C is contraindicated in:
- Individuals with a history of kidney stones or severe renal impairment, as high doses may exacerbate these conditions.
- Patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency, as high doses may increase the risk of hemolysis.
Use Direction
Follow the dosage instructions provided by a healthcare provider or as indicated on the product label. For therapeutic use, adhere to prescribed doses and frequency to ensure safety and effectiveness.
Storage Conditions
Store Vitamin C in a cool, dry place away from direct sunlight and moisture. Keep out of reach of children and ensure the container is tightly closed to maintain potency.
Volume of Distribution
Vitamin C has a relatively low volume of distribution due to its high tissue uptake and rapid renal excretion. It is widely distributed in body tissues, including the adrenal glands, pituitary gland, and leukocytes.
Half Life
The half-life of Vitamin C in the body is approximately 8-40 hours, depending on the dose and individual metabolism. The vitamin is rapidly absorbed and excreted, with levels in plasma reflecting recent intake.
Clearance
Vitamin C is cleared from the body primarily through the kidneys. The clearance rate is influenced by renal function and the level of Vitamin C in the body. Excessive amounts are excreted in the urine.
See in details version Vitamin C [Ascorbic acid] also Vitamin C [Ascorbic acid] in bangla
