SHEET /vs/citric-acid-vs-ascorbic-acid · COMPARISON
Citric acid vs Vitamin C: what is the difference?
How they differ
These two are often confused because both are sour, both come from citrus, and both are used as preservatives, but only one is a vitamin. Ascorbic acid is vitamin C, which humans cannot make and must eat; citric acid is not a vitamin at all and the body produces it constantly as part of the citric acid cycle. Citric acid preserves by lowering pH, while ascorbic acid preserves by being oxidised in place of the food, which is why it stops cut apples browning. Their weights are close, 192.12 and 176.12, and both are white crystalline powders, which is part of why the labels get misread. A product listing citric acid is making no claim about vitamin C.
Side by side
| Citric acid | Vitamin C | |
|---|---|---|
| Formula | C6H8O7 | C6H8O6 |
| Molecular weight | 192.12 g/mol | 176.12 g/mol |
| Family | Organic acids | Vitamins |
| Everyday group | Food & flavor | Nutrient |
| Functional groups | Alcohols, Carboxylic Acids | Alcohols, Esters |
| GHS signal wordThe supplier-filed hazard label, not a statement about ordinary use. | Warning | not recorded |
| Oral LD50A single acute animal measure. It ranks nothing about human safety. | 3,000 mg/kg (oral, rat) | 5,000 mg/kg (oral, rat) |
| Found in | Fruit, Soft drinks, Tonic water, Citrus | Chili peppers, Fruit, Citrus |
| CAS number | 77-92-9 | 50-81-7 |
| PubChem CID | 311 | 54670067 |
Common questions
- What is the difference between Citric acid and Vitamin C?
- These two are often confused because both are sour, both come from citrus, and both are used as preservatives, but only one is a vitamin. Ascorbic acid is vitamin C, which humans cannot make and must eat; citric acid is not a vitamin at all and the body produces it constantly as part of the citric acid cycle. Citric acid preserves by lowering pH, while ascorbic acid preserves by being oxidised in place of the food, which is why it stops cut apples browning.
- Is Citric acid bigger than Vitamin C?
- Citric acid is the heavier molecule, 192.12 g/mol against 176.12 g/mol for Vitamin C. Citric acid is C6H8O7 and Vitamin C is C6H8O6.
- Which has the lower reported LD50, Citric acid or Vitamin C?
- Citric acid, at 3,000 mg/kg (oral, rat), against 5,000 mg/kg (oral, rat) for Vitamin C. An LD50 is one acute animal measurement, and the two here were not necessarily measured in the same species, so it is a data point rather than a ranking of how dangerous either is to a person.
Read the full records: Citric acid and Vitamin C.