Vitamin C (ascorbic acid) is a water-soluble vitamin that humans — unlike most other mammals — cannot synthesise internally. It must be obtained from diet or supplementation. Discovered in the 1930s as the compound that prevents scurvy, vitamin C has since been identified as essential for collagen synthesis, immune cell function, iron absorption, and antioxidant defence throughout the body.
What vitamin C actually does
At the biochemical level, vitamin C acts as an electron donor — it donates electrons to enzymes that require them to function properly. This is critical for collagen synthesis, where two enzymes (prolyl hydroxylase and lysyl hydroxylase) depend on vitamin C to add the hydroxyl groups that stabilise the collagen triple helix. Without adequate vitamin C, collagen is structurally defective, which is why scurvy causes the connective tissue breakdown it does.
Vitamin C also regenerates oxidised vitamin E back to its active antioxidant form, and it participates directly in neutralising reactive oxygen species in aqueous environments (inside cells and in plasma).
Forms of vitamin C
Ascorbic acid is the purest and most studied form. It is identical to vitamin C as it appears in food and is the reference standard against which other forms are measured. It is the most affordable form and has a large body of clinical evidence behind it.
Sodium ascorbate and calcium ascorbate are buffered forms — the ascorbic acid is neutralised with sodium or calcium to produce a less acidic compound. These are commonly recommended for people who experience gastrointestinal discomfort with plain ascorbic acid. The vitamin C content per gram is slightly lower than plain ascorbic acid, but bioavailability is comparable.
Liposomal vitamin C encapsulates ascorbic acid in phospholipid liposomes, similar to the membranes surrounding cells. The theory is that this allows more vitamin C to be absorbed before reaching saturation — the intestinal absorption mechanism for vitamin C is saturable, meaning that above ~200 mg per dose, absorption efficiency declines rapidly. Preliminary studies suggest liposomal C achieves higher plasma levels than equivalent doses of standard ascorbic acid, though large-scale clinical comparisons are limited.
How much do you need?
The RDA for vitamin C is 90 mg/day for adult men and 75 mg/day for adult women. However, plasma saturation — the point where blood levels plateau — is reached at approximately 200 mg/day from food and supplements combined. Doses above 1,000 mg/day significantly increase urinary excretion, and at very high doses (above 2,000 mg/day), gastrointestinal side effects (primarily osmotic diarrhoea) are common. The tolerable upper intake level (UL) set by most health agencies is 2,000 mg/day for adults.
Smokers have measurably lower plasma vitamin C levels and the RDA recommends they consume an additional 35 mg/day to compensate.
Vitamin C in Lebanon
Supplements & More carries vitamin C supplements in multiple forms from US brands, with cash on delivery across Lebanon.