What is vitamin C?
Vitamin C (ascorbic acid) is a water-soluble vitamin your body cannot make or store, so you need a regular supply from food or supplements. It is found in citrus, capsicum, berries, and many vegetables. It plays a role in immune health, collagen synthesis, antioxidant defence, and helping your body absorb iron from plant foods.
How it works
Vitamin C acts as an antioxidant, helping protect cells from oxidative stress, and it is essential for producing collagen, the protein that builds skin, tendons, and connective tissue. It also boosts the absorption of non-heme iron, which is why it is often paired with iron-rich plant foods or collagen supplements.
What the research says
- Essential for immune function, with deficiency clearly impairing it
- Supports collagen production, useful alongside collagen supplements for connective tissue
- Improves absorption of iron from plant sources when taken together
- May slightly reduce the duration of colds, though it does not prevent them
- Benefits are most noticeable when correcting a low intake rather than megadosing
Effective dose
200–500mg per day comfortably covers needs and saturates the body's tissues for most people. Higher doses are not better, as your body simply excretes the excess in urine. If pairing with collagen for connective tissue, taking vitamin C alongside it makes sense given its role in collagen synthesis.
What to check on the label
Plain ascorbic acid is perfectly effective and cheap. You do not need expensive liposomal or buffered versions for general health. Check the dose per serve, and be wary of mega-dose products marketing thousands of milligrams, which offer no extra benefit for most people.
Safety
Vitamin C is very safe, as excess is simply flushed out. Very high doses, above 2000mg a day, can cause digestive upset and may raise the risk of kidney stones in susceptible people. Sensible doses in the few hundred milligram range avoid this entirely.