
Introduction
Vitamin C, also known as L-ascorbic acid is one of the many important antioxidants that can neutralise harmful free radicals.
It’s an essential dietary component as humans are unable to synthesise vitamin C endogenously. [1]
It is also needed to make collagen, a fibrous protein in connective tissue, which is important for wound healing. [1]
It is important to include plenty of vitamin C-containing foods in your diet daily as it’s a water-soluble nutrient and the body does not store this vitamin well. [2]
However, absorption decreases as intake increases and hence it is recommended to limit the consumption to adequate levels only.
Also, high heat cooking or prolonged cooking time can destroy the nutrient. Quick heating methods like stir-fry or blanching in little water can preserve the vitamin. [2]

- Vitamin C is absorbed in the intestine and has a limited ability to absorb the nutrient. [1]
- Around 70 to 90% of usual dietary intakes of ascorbic acid (30 to 180 mg/day) is absorbed in the intestine. [1]
- However, absorption falls to about 50% or less with increasing doses above 1 g/day. [1]

- The total body content of vitamin C ranges from 300 mg to about 2 g. [1]
- According to researchers, ingested vitamin C can last in our body for weeks. [13]
- Vitamin C is stored in different body tissues in varying levels. For instance, it is stored in the pituitary and adrenal glands, leukocytes, eye tissue and humours, and the brain in high levels, while it is stored in low levels in plasma and saliva. [6]
- With large intakes, unabsorbed vitamin C degrades in the intestine and may lead to gastrointestinal discomforts and diarrhoea. [7]

- The body excretes excess vitamin C mainly through urine and high intakes can also increase urinary oxalate and uric acid excretion. [1]
- Metabolic losses in healthy non-smoking adults are estimated to be around 40-50 mg/day, whereas the metabolic losses in smokers are estimated to be around 50-114 mg/day as a result of high oxidative stress. [12]
Body Functions

Recommended Daily Intake

Deficiency Symptoms

Vitamin C Food Sources

Excessive Intake/ Toxicity Side Effects

Groups At Risk of Vitamin C Deficiency
Vitamin C Interaction With Other Nutrients
- Iron – Vitamin C may enhance the absorption of nonheme iron, the type of iron found in plant foods such as leafy greens. [1,6]
- Copper – Excess vitamin C may reduce copper absorption. [6]
- Vitamin B12 – Large doses of vitamin C may reduce vitamin B-12 levels in the body. [1,6]
- Aluminium – Taking vitamin C can increase your absorption of aluminium from medications containing aluminium.[10]
- Vitamin E – Vitamin C is an important physiological antioxidant and can regenerate other antioxidants within the body, including alpha-tocopherol (vitamin E). [1]
- Chromium – Vitamin C may enhance chromium absorption. [14]