Vitamin C 15 %

• Scurvy Treatment: Typically 100 mg to 250 mg once or twice daily for several days, followed by a maintenance dose.
• Urinary Acidification: Doses may range from 4 g to 12 g daily, divided into several smaller doses throughout the day.
• Dietary Supplementation: The Recommended Dietary Allowance (RDA) for healthy adults is generally 75–90 mg daily.

• Scurvy: 100 mg to 300 mg daily in divided doses is common for children, though specific dosing must be determined by a pediatrician based on age and weight.
• Supplementation: Pediatric doses are significantly lower than adult doses and vary by age group (e.g., 15–45 mg daily).

Renal Impairment

Patients with a history of kidney stones (nephrolithiasis) or renal failure should use Ascorbic Acid with caution. High doses can lead to the accumulation of oxalate, increasing the risk of stone formation.

Hepatic Impairment

No specific dosage adjustments are typically required for patients with liver disease, though overall nutritional status should be monitored.

Elderly Patients

No specific age-related adjustments are required, though healthcare providers should consider the patient's total dietary intake and renal function.

• Administration: Oral forms may be taken with or without food. Taking it with food may reduce the risk of stomach upset.
• Extended Release: Swallow whole; do not crush or chew extended-release tablets as this can release the medication too quickly.
• Storage: Store at room temperature (68°F to 77°F) away from moisture, heat, and direct light. Ascorbic acid can darken if exposed to air.

If you miss a dose, take it as soon as you remember. If it is almost time for your next scheduled dose, skip the missed dose. Do not double the dose to catch up.

Signs of acute overdose may include severe diarrhea, nausea, and abdominal cramps. In patients with G6PD deficiency, massive doses may cause hemolysis (breakdown of red blood cells). Seek emergency medical attention or contact a Poison Control Center immediately if an overdose is suspected.

> Important: Follow your healthcare provider's dosing instructions. Do not adjust your dose without medical guidance.

While generally well-tolerated at recommended doses, high intake may cause:

• Gastrointestinal Distress: Nausea, vomiting, and diarrhea are common when doses exceed 2,000 mg per day.
• Abdominal Cramping: A feeling of bloating or sharp pains in the stomach area.

• Heartburn: A burning sensation in the chest or throat (acid reflux).
• Headache: Mild to moderate tension-type headaches.
• Insomnia: Difficulty falling or staying asleep, particularly if taken late in the day.

• Hyperoxaluria: Excessive excretion of oxalate in the urine, which can lead to kidney stones.
• Flushing: Temporary redness or warmth of the skin.
• Urinary Frequency: An increased need to urinate due to the acidifying effect on the bladder.

> Warning: Stop taking Ascorbic Acid and call your doctor immediately if you experience any of these.

• Severe Allergic Reaction: Symptoms include rash, itching, severe dizziness, or swelling of the face, tongue, and throat.
• Kidney Stone Symptoms: Intense pain in the side or back (renal colic), blood in the urine, or painful urination.
• Hemolysis: In patients with G6PD deficiency, symptoms include fatigue, pale skin, or dark-colored urine.

Prolonged use of very high doses (megadoses) may lead to the development of calcium oxalate kidney stones. There is also a theoretical risk of "rebound scurvy" if high doses are suddenly discontinued, as the body's metabolic clearance mechanisms remain accelerated for a period of time.

No FDA black box warnings for Ascorbic Acid. It is generally recognized as safe (GRAS) when used according to established guidelines.

Report any unusual symptoms to your healthcare provider.

Ascorbic Acid is an essential nutrient, but pharmacological doses require medical supervision. It is important to distinguish between nutritional supplementation and high-dose therapeutic use.

No FDA black box warnings for Ascorbic Acid.

• G6PD Deficiency: Patients with glucose-6-phosphate dehydrogenase deficiency should avoid high doses of Vitamin C due to the risk of oxidative stress leading to hemolytic anemia.
• Oxalosis/Kidney Stones: Individuals with a history of hyperoxaluria or calcium oxalate stones should limit their intake, as Ascorbic Acid is metabolized into oxalate.
• Hemochromatosis: Because Vitamin C increases the absorption of non-heme iron, patients with iron overload disorders (like hemochromatosis or thalassemia) should use caution to avoid iron toxicity.
• Diabetes: High doses of Ascorbic Acid may interfere with the accuracy of certain blood glucose monitoring systems. Always inform your doctor if you are using high-dose supplements.

For most patients, routine lab monitoring is not required. However, those on high-dose therapy or those with renal impairment may require:

• Urinary Oxalate Levels: To assess the risk of stone formation.
• Serum Iron/Ferritin: In patients with iron storage diseases.
• Renal Function Tests: Including serum creatinine and GFR (Glomerular Filtration Rate).

Ascorbic Acid does not typically interfere with the ability to drive or operate heavy machinery.

Chronic alcohol consumption can deplete Vitamin C levels in the body. While there is no direct contraindication, alcohol may reduce the efficacy of supplementation by impairing intestinal absorption.

If you have been taking very high doses (several grams daily) for a long period, your healthcare provider may suggest a gradual reduction in dose to prevent a temporary deficiency state known as rebound scurvy.

> Important: Discuss all your medical conditions with your healthcare provider before starting Ascorbic Acid.

There are no absolute drug-drug contraindications that require complete avoidance; however, specific clinical scenarios require extreme caution.

• Warfarin (Coumadin): High doses of Ascorbic Acid (over 1g) may interfere with the anticoagulant effect of warfarin, potentially lowering the INR (International Normalized Ratio) and increasing the risk of clots. Close monitoring of coagulation parameters is required.
• Deferoxamine: When used with Vitamin C, this iron-chelating agent may increase iron toxicity, particularly in the heart. Vitamin C should usually be started only after the first month of deferoxamine therapy.

• Aspirin: Can increase the excretion of Ascorbic Acid and decrease its blood levels; conversely, Vitamin C may decrease the excretion of aspirin, potentially increasing aspirin levels.
• Estrogens/Oral Contraceptives: Ascorbic Acid may increase estrogen levels by inhibiting their metabolism, which could increase the risk of side effects from hormonal therapy.
• Aluminum-containing Antacids: Vitamin C can increase the amount of aluminum absorbed from antacids, which may be dangerous for patients with kidney disease.

• Iron-Rich Foods: Ascorbic Acid significantly enhances the absorption of non-heme iron (found in plant foods). While beneficial for many, this must be managed in patients with iron overload.

• Multivitamins: Ensure that the total intake of Vitamin C from all supplements does not exceed the Tolerable Upper Intake Level (UL) of 2,000 mg per day for adults.

• Glucose Tests: High doses can cause false-positive or false-negative results in urine glucose tests and some finger-stick blood glucose monitors.
• Occult Blood Tests: May cause false-negative results in stool tests for hidden blood (Guaiac-based tests).

> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking.

• Hypersensitivity: Ascorbic Acid must never be used in patients with a known severe allergy to any component of the formulation.
• Severe Renal Failure: In cases of end-stage renal disease where oxalate clearance is impossible, high-dose Ascorbic Acid is contraindicated due to the risk of systemic oxalosis.

• History of Nephrolithiasis: Patients with recurrent calcium oxalate kidney stones require a careful risk-benefit analysis before starting high-dose therapy.
• G6PD Deficiency: Due to the risk of acute hemolysis, healthcare providers will typically avoid prescribing doses significantly above the RDA.
• Hemochromatosis: Use is restricted in patients with symptomatic iron overload unless closely monitored by a hematologist.

There is no significant cross-sensitivity reported between Ascorbic Acid and other vitamins or pharmacological classes.

> Important: Your healthcare provider will evaluate your complete medical history before prescribing Ascorbic Acid.

• Category: FDA Pregnancy Category A (at RDA doses) or C (at high doses).
• Risks: Ascorbic Acid is naturally present in the maternal diet and is essential for fetal development. However, excessive doses during pregnancy may lead to "rebound scurvy" in the neonate after birth. It should only be used in doses exceeding the RDA if clearly needed and directed by a physician.

Ascorbic Acid is excreted into breast milk. While it is safe and necessary for the nursing infant, the American Academy of Pediatrics suggests that maternal intake should stay within the recommended daily limits to avoid potential issues.

Ascorbic Acid is approved for use in children for the treatment of scurvy and as a nutritional supplement. Dosing must be strictly age-appropriate, as children are more sensitive to the gastrointestinal effects of high doses.

Elderly patients may have a higher prevalence of renal impairment. Healthcare providers should monitor kidney function and ensure that high-dose Vitamin C does not contribute to stone formation or interact with common medications like warfarin.

Patients with a GFR (Glomerular Filtration Rate) below 30 mL/min should avoid high-dose Ascorbic Acid (typically >500 mg/day) due to the risk of secondary oxalosis and kidney stone progression.

No specific adjustments are required for hepatic impairment, though these patients often have underlying nutritional deficiencies that may necessitate supplementation.

> Important: Special populations require individualized medical assessment.

Ascorbic Acid acts as an electron donor for enzymes involved in collagen hydroxylation, carnitine biosynthesis, and norepinephrine synthesis. It also acts as a non-enzymatic antioxidant, scavenging free radicals and protecting cellular components from oxidative damage. Its Acidifying Activity [MoA] occurs because it is a weak acid that is partially excreted unchanged in the urine, thereby lowering the pH.

• Onset: For scurvy, improvement in symptoms (like bleeding gums) can be seen within 24–48 hours of starting therapy.
• Duration: As a water-soluble vitamin, it has a short duration of action and must be replenished daily.
• Tolerance: The body does not typically develop a tolerance to the vitamin's effects, but it does adjust its rate of excretion based on intake levels.

| Parameter | Value |

|---|---|

| Bioavailability | 70%–90% (at low doses) |

| Protein Binding | Low (approx. 25%) |

| Half-life | 10–20 days (stored), 3–4 hours (excess) |

| Tmax | 2–3 hours (oral) |

| Metabolism | Hepatic; oxidized to dehydroascorbate |

| Excretion | Renal (100% of excess) |

• Molecular Formula: C6H8O6
• Molecular Weight: 176.12 g/mol
• Solubility: Highly soluble in water; sparingly soluble in alcohol.
• Structure: A six-carbon lactone with an enediol group, which provides its reducing properties.

Ascorbic Acid is classified as a water-soluble vitamin within the Vitamin C [EPC] group. It is therapeutically categorized as a nutritional supplement and a urinary acidifying agent.