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Vitamin C
Vitamin — Ascorbic AcidNigerian brand names:AscovitChewvitAscorvitRedoxonCelinC-Pure
Reviewed by the PMC Medical Team · Promise Medical Centre
Overview
Vitamin C (ascorbic acid) is a water-soluble essential vitamin that the human body cannot synthesise on its own — it must be obtained from diet or supplements. It plays a central role in the immune system, collagen synthesis (needed for wound healing, skin, and connective tissue), iron absorption, and as a powerful antioxidant. Deficiency causes scurvy — a disease characterised by bleeding gums, poor wound healing, and fatigue. In Nigeria, where dietary diversity may be limited, supplementation is common, though most Nigerians who eat fresh fruits and vegetables obtain sufficient vitamin C from food.
Uses
Vitamin C supplementation is used to:
- Treat vitamin C deficiency and scurvy
- Enhance iron absorption: Taking vitamin C with iron supplements (ferrous sulfate) significantly increases how much iron the body absorbs from the gut — recommended in iron deficiency anaemia
- Immune support: High-dose vitamin C may slightly reduce the duration and severity of colds (evidence modest but consistent)
- Wound healing support: Adequate vitamin C is needed for proper tissue repair
- Antioxidant protection: Protects cells against damage from free radicals
- During pregnancy: Helps meet increased demands; supports foetal development; often included in antenatal supplements
- Alongside certain medications: Used to protect against oxidative stress during illness or treatment
How to Use
Vitamin C is available as tablets (standard and chewable), effervescent tablets, capsules, and syrups.
Recommended daily intake (dietary reference values):
- Adults: 40–80 mg/day from diet; supplementation usually 250–1000 mg daily
- Pregnancy: 80–85 mg/day (higher in developing countries where diet may be inadequate)
- Breastfeeding: 100–120 mg/day
- Upper tolerable intake: 2000 mg/day in adults
For iron absorption enhancement:
- Take vitamin C (250–500 mg) at the same time as your iron supplement — this significantly improves iron absorption
General:
- Chewable tablets: Rinse mouth with water after taking — the acidity can erode tooth enamel with frequent use
- Effervescent tablets: Dissolve completely in water before drinking
- Can be taken with or without food
- If taking high doses: Spread through the day — the body excretes excess vitamin C via urine, so very large single doses are largely wasted
Side Effects
Vitamin C is generally very well tolerated at recommended doses.
High-dose side effects (>1000 mg/day):
- Nausea, stomach cramps, and heartburn
- Diarrhoea (the most common symptom of too much vitamin C — called "bowel tolerance")
- Headache
- Flushing
Kidney stones:
- People with a history of calcium oxalate kidney stones should avoid high doses of vitamin C (> 500 mg/day) — it can increase urinary oxalate and stone risk
Excess vitamin C is excreted in urine and not stored — toxicity from dietary sources alone is extremely unlikely.
Warnings & Precautions
Vitamin C is very safe for most people at standard doses.
G6PD deficiency: High-dose IV vitamin C (in hospital settings) can trigger haemolytic anaemia in people with G6PD deficiency — a common genetic condition in West Africans. Oral supplementation at normal doses is generally safe.
Kidney disease: People with kidney failure cannot excrete excess vitamin C efficiently — high doses can cause oxalate accumulation. Limit to dietary amounts if on dialysis.
Haemochromatosis (iron overload): Vitamin C enhances iron absorption — people with iron overload disorders should avoid high-dose vitamin C supplementation.
Sickle cell disease: Some evidence that high-dose vitamin C may worsen sickle cell crises in rare cases — use cautiously in sickle cell disease.
Do not rely on vitamin C supplements to prevent or treat serious infections: While vitamin C supports immune function, it is not a substitute for vaccines, antibiotics, antimalarials, or prescribed medical treatment. "Megadose" claims circulating on social media in Nigeria are not supported by strong clinical evidence.
Drug Interactions
Important interactions:
- Iron supplements: Vitamin C taken at the same time enhances iron absorption — beneficial when treating iron deficiency anaemia, but avoid combining with iron therapy in haemochromatosis
- Aluminium-containing antacids: Vitamin C increases aluminium absorption from antacids — take them separately
- Warfarin (blood thinner): High-dose vitamin C (more than 1000 mg/day) may interfere with anticoagulant monitoring — inform your doctor
- Chemotherapy drugs: High-dose vitamin C may interfere with some cancer treatments — discuss with oncologist before supplementing during chemotherapy
- Aspirin and NSAIDs: May reduce absorption of vitamin C; aspirin also increases vitamin C excretion
- Desferrioxamine (iron chelating agent): Vitamin C can enhance iron mobilisation — can be beneficial but requires careful monitoring
Storage
Store at room temperature (below 25°C) in a dry place, away from direct sunlight and moisture. Effervescent tablets: keep the tube tightly closed. Chewable tablets: keep in airtight container. Do not refrigerate (attracts moisture). Keep out of reach of children.
Buy only NAFDAC-registered medications
Nigeria has a significant problem with counterfeit and substandard drugs. Always purchase medications from a licensed pharmacy and check the NAFDAC registration number on the package — verify at nafdac.gov.ng.