Ascorbic acid (Vitamin C)
Ascorbic acid (E300) is vitamin C, added to foods as an antioxidant to prevent browning and preserve colour and nutrients. It is an essential nutrient with a very favourable safety profile and is one of the most benign food additives.
Ascorbic acid is water-soluble vitamin C. As E300 it is added to cured meats, fruit products, and baked goods to mop up oxygen, keeping colour and flavour stable and slowing nutrient loss.
It is an essential dietary nutrient; excess intake is generally excreted in urine. EFSA classes it as safe with no numeric limit, and it is treated as a low-concern additive.
On the label
- E-number
- E300
- INS number
- INS 300
- Functional class
- Antioxidant
- Also known as
- Vitamin C · L-ascorbic acid · Antioxidant 300 · INS 300
Frequently asked questions
Yes. Ascorbic acid (specifically L-ascorbic acid) is the chemical name for vitamin C; on a food label, E300 means vitamin C used as an additive. Because the human body cannot make or store vitamin C, it has to come from the diet.
They are the same molecule, so the body uses them in the same way. Manufactured ascorbic acid is made from glucose and is chemically identical to the vitamin C in fruit and vegetables, so there is no meaningful nutritional difference in the vitamin itself. Whole foods do, of course, provide fibre and other nutrients alongside their vitamin C.
Mostly as an antioxidant/preservative: it slows oxidation, helping prevent browning (for example in cut fruit) and protecting colour and flavour. The US FDA lists ascorbic acid as a GRAS chemical preservative, and it is authorised for these uses as a food additive in the EU; it can also be used to add vitamin C to foods.
It is regarded as safe: authorised in the EU and GRAS in the US, and because vitamin C is water-soluble, any excess is mainly passed out in urine. Very high supplemental doses — the NHS notes more than about 1,000 mg a day — can cause stomach pain, diarrhoea and wind, which settle once you cut back; the small amounts used as the additive E300 are far below this. This is general information, not medical advice.
Yes. Ascorbic acid (E300) is manufactured industrially from glucose, a plant sugar, rather than from animal sources, so plain vitamin C additive is generally considered suitable for vegans. (Note that some related substances, such as ascorbyl palmitate, are different additives.)
Vitamin C is a normal nutrient, and the small amounts used as the additive E300 are not a pregnancy concern; the NHS advises that a healthy, varied diet provides most of the vitamins and minerals you need in pregnancy. Routine high-dose vitamin C supplements are not specifically recommended, and NHS pregnancy advice focuses on folic acid and vitamin D while avoiding high-dose vitamin A. Always check with your midwife or doctor before taking supplements.
Yes — it contains no animal-derived material. It is manufactured from glucose, most often by a fermentation-based process. The same applies to a vegetarian diet.
Yes — the additive itself contains no gluten. A gluten-free claim belongs to the finished product, though — check the pack, not the additive.
It is manufactured from glucose, most often by a fermentation-based process and contains no animal-derived material, so the additive itself is not inherently non-halal. Certification applies to a finished product rather than to an additive, so a halal certification mark on the pack is the authoritative signal.
Ascorbic acid is vitamin C, and as an additive it is among the least concerning: EFSA classes it as safe, with no numerical acceptable daily intake judged necessary. Very large supplemental doses — far above anything used to preserve food — can cause digestive upset, but the amounts used as an antioxidant in food are a small fraction of a normal dietary intake.