Vitamin C: Forms Compared
Choosing between a 1,000 mg effervescent, a gentle buffered capsule and a fruity gummy can feel confusing. This guide sorts out the forms of vitamin C, what the EU reference amount is, where sensible daily intakes sit and what to check on the label.
What vitamin C is and what it does
Vitamin C, also called ascorbic acid, is a water-soluble vitamin. Humans cannot make it, so it has to come from food or supplements every day, and because the body does not store large amounts, any excess is passed out in urine. It is involved in making collagen, the protein that gives structure to skin, bones, gums and blood vessels, and it acts as an antioxidant in the body's fluids.
The EU has authorised a long list of health claims for vitamin C. The most useful ones for shoppers are shown word for word in the authorised claims box below, including its role when taken together with iron.
Forms you'll see on labels
| Form | What to know |
|---|---|
| Ascorbic acid | The most common and most studied form. Research has not shown any form of vitamin C to be superior to the others. |
| Sodium ascorbate | A buffered, less acidic form. Each gram supplies about 115 mg of sodium, which matters if you watch your salt intake. |
| Calcium ascorbate | Another buffered form, sometimes sold under trade names. It adds a small amount of calcium. |
| With bioflavonoids or rose hip | Vitamin C combined with plant compounds. The vitamin C content on the label is what counts towards your intake. |
| Effervescent tablets | Dissolve in water. They often contain a significant amount of sodium, so check the nutrition panel. |
| Liposomal vitamin C | Vitamin C wrapped in fat-based particles. Evidence comparing it with standard forms is limited. |
Examples from our shelves for some of the forms in the table above.
How much vitamin C: NRV, typical amounts and upper limit
- EU NRV: 80 mg a day. A product with 80 mg per serving shows 100% NRV.
- Common supplement amounts: 80–250 mg in multivitamins and combination products; 500–1,000 mg in single vitamin C products.
- Upper limit: EFSA has not set an upper limit because data were not adequate to derive one. UK guidance says that taking less than 1,000 mg a day from supplements is unlikely to cause harm, while larger amounts can cause stomach pain, diarrhoea and wind, which settle once the dose is reduced.
Food sources are plentiful: citrus fruit, guava, kiwi, strawberries, red and green peppers, broccoli, tomatoes and potatoes. Vitamin C is sensitive to heat and long storage, so fresh or lightly cooked produce keeps more of it. Compare strengths in our vitamin C collection.
Who should check with a doctor or pharmacist first
- People with a history of kidney stones or kidney disease: high-dose vitamin C is not suitable for everyone, so ask before taking 500 mg or more daily.
- People with iron overload conditions such as haemochromatosis, because vitamin C taken with iron-rich meals increases the iron the body takes up.
- Anyone having chemotherapy or radiotherapy: antioxidant supplements may interact with these therapies, so speak to your oncology team first.
- People taking cholesterol-lowering medicines: one study found an antioxidant mix including vitamin C reduced the effect of a statin-plus-niacin combination.
- Pregnancy, breastfeeding and children: follow the age and use on the pack and get advice before using high-strength products.
- Before blood or urine tests: large doses can interfere with some laboratory tests, so mention any supplements when tests are arranged.
How to read a vitamin C label
- Check the amount per serving. "1,000 mg" may refer to two tablets, not one.
- Read the %NRV. 500 mg is 625% NRV. High percentages are common for vitamin C and are not a sign of a better product.
- Look at the form. If the label names sodium ascorbate or an effervescent base, look for the sodium content per serving.
- Watch sugar in gummies and the acidity of chewables, which some people prefer to follow with water.
- Add up your products. Vitamin C appears in multivitamins, iron products, collagen drinks and electrolyte powders, so total your daily intake.
Bahrain and GCC notes
Vitamin C breaks down with heat, light and humidity. Keep the lid tightly closed, store below 25°C and away from bathroom steam, and close effervescent tubes straight after use. Fasting during Ramadan leaves fewer eating windows, so if you take vitamin C with iron, pairing both at iftar or suhoor is a practical routine. Explore the range in our vitamin C collection.
Reading a real label
AMERIX Vitamin C 250 mg, 60 Gummies| On the label | What it means |
|---|---|
| 250 mg vitamin C per 2 gummies | The daily serving |
| 313% NRV | 250 mg against the 80 mg reference intake |
| 3 g sugars per serving | Worth counting if you watch sugar |
| Gelatine-free, vegetarian | Check this line if you avoid gelatine |
| 60 gummies, 2 a day | A 30-day supply |
- Vitamin C contributes to the normal function of the immune system
- Vitamin C contributes to the reduction of tiredness and fatigue
- Vitamin C contributes to normal collagen formation for the normal function of skin
- Vitamin C contributes to the protection of cells from oxidative stress
- Vitamin C increases iron absorption
- Vitamin C contributes to normal energy-yielding metabolism
Applies to products that provide at least 15% of the NRV per daily portion (a 'source of' the nutrient).
Products with Vitamin C
Always read the label and check the amount per serving.
Dealtha PharmaDealtha Pharma FerroC, 30 CapsulesBHD11.990
DAY2DAYDay2Day The Collagen Beauty Intense, 30 SachetsBHD29.400
Known NutritionKnown Nutrition Hair, Skin and Nails, 60 GummiesBHD16.500
MediTechMeditech OptiFer C Iron 18 mg + Vitamin C 80 mg, 60 TabletsOut of stockFrequently asked questions
Is 1,000 mg of vitamin C a day safe?
EFSA has not set an upper limit. UK guidance says under 1,000 mg a day from supplements is unlikely to cause harm, while higher amounts can upset the stomach.
Which form of vitamin C should I choose?
Research has not shown one form to be superior. Buffered forms such as sodium or calcium ascorbate are less acidic, which some people find gentler.
Should I take vitamin C with iron?
Many people take them together because vitamin C increases iron absorption. Ask your doctor first if you have an iron overload condition.
Do effervescent tablets contain salt?
Many do. Check the nutrition panel for sodium per tablet, especially if you have been advised to limit salt.
Can I get enough vitamin C from food?
Most people can reach 80 mg a day from fruit and vegetables such as guava, citrus, kiwi and peppers.
