Vitamin C

Vitamin C is a water-soluble vitamin medicine available in Bangladesh under many brand names. Below are its uses, dosage, side effects and precautions — and all brands with their current prices.

• Prevention and treatment of vitamin C deficiency.
• Treatment of scurvy caused by severe vitamin C deficiency.
• Supplementation when dietary intake is inadequate or requirements are increased, as advised by a healthcare professional.

Adult dosing depends on the reason for use, the dosage form, diet, medical condition, and deficiency severity. For routine supplementation, use the dose on the product label or as advised by a registered doctor or pharmacist. Higher doses for confirmed deficiency or scurvy, and injectable vitamin C, should be used only under medical supervision.

• Usually well tolerated at recommended doses.
• Common side effects may include nausea, abdominal cramps, heartburn, and diarrhoea, especially with higher doses.
• High doses may increase urinary oxalate and can contribute to kidney stones in susceptible individuals.
• Rare serious reactions include allergic reactions, particularly with injectable products.
• Very high doses may rarely cause haemolysis in people with G6PD deficiency.

Use caution in people with kidney disease, a history of kidney stones, hyperoxaluria, haemochromatosis or other iron-overload disorders, thalassaemia, G6PD deficiency, or those needing strict medical monitoring. Vitamin C can interfere with some laboratory tests, including certain glucose and stool occult blood tests. Use under a registered doctor's or pharmacist's guidance, especially for children, pregnancy, breastfeeding, chronic illness, high-dose use, or injections.

• May increase absorption of non-haem iron; caution is needed in iron-overload disorders or when taking iron supplements.
• Large doses may affect the results of some urine glucose tests and other laboratory tests.
• Aluminium-containing antacids may be absorbed more with vitamin C; people with kidney disease should seek medical advice.
• Patients taking warfarin or other long-term medicines should consult a doctor or pharmacist before using high-dose vitamin C.
• Discuss use with an oncologist before taking high-dose antioxidant supplements during chemotherapy or radiotherapy.

• Known hypersensitivity to vitamin C/ascorbic acid or any component of the product.
• Do not use injectable vitamin C without appropriate medical indication and supervision.
• Avoid high-dose use in people with significant hyperoxaluria, recurrent oxalate kidney stones, or severe kidney impairment unless specifically advised by a doctor.

Vitamin C is required during pregnancy and breastfeeding and is generally safe at recommended dietary or prescribed doses. Avoid unnecessary high-dose supplementation unless advised by a doctor, because excessive intake may not be beneficial and may increase side effects.

Store in a cool, dry place away from direct light, heat, and moisture. Keep the container tightly closed and out of the reach of children. Follow the label instructions for reconstituted powders, drops, gums, and injectable products, and do not use after the expiry date.