Your guide to ascorbic acid (vitamin C): benefits, uses and how to take it safely
Written byH&B editorial team
Reviewed byLaura Jennings
What’s ascorbic acid, is it different to vitamin C and why do we need it? Find out the benefits and juicy details
Summary
1What’s ascorbic acid and what does it do?
Ascorbic acid is, in fact, vitamin C. It contributes to normal collagen formation, supporting our skin, bones, teeth and cartilage.
2Vitamin C supports iron absorption
Not only is vitamin C useful in itself, but it can enhance the way other nutrients work. Vitamin C helps increase absorption of non-heme iron.
3Can you buy vitamin C without ascorbic acid?
Most supplements use ascorbic acid. However, you can also find other forms, such as sodium or calcium ascorbate, which may be gentler on the stomach.
Ascorbic acid is an important nutrient for helping keep our bodies and skin healthy. But what is it? While you might not think you know much about it, you may be surprised that you probably do (clue: it goes by a different name)...
What’s ascorbic acid and what does it do?
Ascorbic acid is, in fact, vitamin C. It contributes to normal collagen formation, which plays a key role in the normal function of our skin, bones, teeth, and cartilage.1-4 Vitamin C (ascorbic acid) is also essential for protecting cells, supporting our immunity and more – we'll dive deeper below.5,6
Over time, not having enough vitamin C can lead to a condition called scurvy (severe vitamin C deficiency) that can cause symptoms like bleeding from the gums, bruising and joint and muscle pain.7 Fortunately, it’s possible to get all the vitamin C we need from our diet. The best sources of it are mainly found in fruit and veg.8 However, vitamin C can’t be stored in the body, so it’s important to get it in your diet every day.8
What are the benefits of ascorbic acid?
Now you know the basics of ascorbic acid, let’s move on to its benefits for the body:
- Vitamin C contributes to normal collagen formation
Vitamin C contributes to normal collagen formation, which is an important component of skin, bones, cartilage and other connective tissues.1,2,4 Since collagen helps form the connective tissues that support our joints and muscles, getting enough vitamin C is an important part of overall musculoskeletal health. - Vitamin C may support your beauty routine
Vitamin C’s collagen support also means it’s a useful ingredient in beauty. When applied topically, research suggests that vitamin C may help support skin health and overall appearance.9As an antioxidant, vitamin C helps protect cells from oxidative stress and supports overall skin health and appearance.6,10 That’s why you’ll often find it in so many skincare products like moisturisers, serums or eye creams. - Vitamin C supports iron absorption
Not only is vitamin C useful in itself, but it can enhance the way other nutrients work. Vitamin C helps increase absorption of non-heme iron (the type of iron we get from plant-based foods, like leafy greens).11 Non-heme iron is a little more difficult to absorb than heme iron (the type of iron we get from meat and fish), so this is particularly important if you’re vegetarian or vegan. When you eat a plant-based, iron-rich meal, try to include a food containing vitamin C at the same time – it’ll help your body absorb more of it. - Vitamin C supports immune health
You might also know that ascorbic acid is famous for supporting immune health.5 While it can’t get rid of a cold or ‘boost’ your immunity, regular vitamin C intake is vital for a normal immune system.11
Am I getting enough vitamin C?
Ascorbic acid is the form of vitamin C commonly used in foods and supplements to help maintain adequate vitamin C levels. You may be more at risk of deficiency if you:7,11
- eat a limited diet
- have difficulty absorbing nutrients
- smoke, as smoking increases the body’s vitamin C requirements due to higher oxidative stress
Ascorbic acid FAQs
Vitamin C is the general umbrella term, which covers ascorbic acid and related compounds. So ascorbic acid is a type of vitamin C, but they’re not interchangeable. L-ascorbic acid is synthetically made, but it’s identical to ‘natural’ vitamin C. It’s usually used as a dietary supplement to support adequate intake.
Most supplements contain ascorbic acid, the active form of vitamin C. However, you can also find other forms, such as sodium or calcium ascorbate, which may be gentler on the stomach for some people.12 All of these forms contribute to your overall vitamin C intake. If you’re planning to take ascorbic acid or another form of vitamin C, speak to your GP to make sure it’s okay for you to do so and that you take the right amount based on your specific health needs.
According to NHS guidance, adults aged between 19 and 64 need 40mg of vitamin C a day.8 Taking more than 1000mg a day may cause side effects and may increase the risk of kidney stones in some people, as well as diarrhoea.8 Those with a history of kidney stones may need to be cautious with high-dose vitamin C.13
When taking a new supplement, it's important to be aware of any side effects and risks you might notice. It's possible to experience some side effects when taking ascorbic acid supplements, including diarrhoea, headaches or nausea.14
The final say
The best way to get your ascorbic acid is from a colourful range of fruit and veg. But if your intake is low or you don’t get much vitamin C in your diet, an ascorbic acid or vitamin C supplement might be useful (as long as you’ve got the thumbs up from your GP). And why not brighten your day with a vitamin C-rich recipe? We’ve got a ginger tadka dal, shakshuka with black beans and five-ingredient pink fluff ice cream to choose from...
Disclaimer – This article provides informational advice and is not a substitute for medical care. Working with experts for accuracy, we take great care to ensure the information is up-to-date and relevant. However, you should always consult your GP or healthcare professional before using supplements or alternative products, particularly if you have medical conditions or are under supervision.
1. European Commission. Characteristics [Internet]. European Commission [cited 2026 Feb 24]. Available from: https://ec.europa.eu/food/food-feed-portal/screen/health-claims/eu-register/details/POL-HC-6505
2. European Commission. Characteristics [Internet]. European Commission [cited 2026 Feb 24]. Available from: https://ec.europa.eu/food/food-feed-portal/screen/health-claims/eu-register/details/POL-HC-6502
3. European Commission. Characteristics [Internet]. European Commission [cited 2026 Feb 24]. Available from: https://ec.europa.eu/food/food-feed-portal/screen/health-claims/eu-register/details/POL-HC-6506
4. European Commission. Characteristics [Internet]. European Commission [cited 2026 Feb 24]. Available from: https://ec.europa.eu/food/food-feed-portal/screen/health-claims/eu-register/details/POL-HC-6503
5. European Commission. Characteristics [Internet]. European Commission [cited 2026 Feb 24]. Available from: https://ec.europa.eu/food/food-feed-portal/screen/health-claims/eu-register/details/POL-HC-6510
6. European Commission. Characteristics [Internet]. European Commission [cited 2026 Feb 24]. Available from: https://ec.europa.eu/food/food-feed-portal/screen/health-claims/eu-register/details/POL-HC-6511
7. NHS. Scurvy [Internet]. NHS [cited 2026 Feb 24; reviewed 2023 Sep 27]. Available from: https://www.nhs.uk/conditions/scurvy/
8. NHS. Vitamin C [Internet]. NHS [cited 2026 Feb 24; reviewed 2020 Aug 3]. Available from: https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-c/
9. De Dormael R et al. Vitamin C Prevents Ultraviolet-induced Pigmentation in Healthy Volunteers: Bayesian Meta-analysis Results from 31 Randomized Controlled versus Vehicle Clinical Studies. J Clin Aesthet Dermatol [Internet]. 2019 Feb 1 [cited 2026 Feb 25]. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC6415704/
10. Rinnerthaler M, Bischof J, Streubel MK, Trost A, Richter K. Oxidative Stress in Aging Human Skin. Biomolecules [Internet]. 2015 Apr 21 [cited 2026 Feb 25]; 5(2): 545-89. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC4496685/
11. National Institutes of Health (NIH). Vitamin C [Internet]. NIH [reviewed 2025 Jul 31; cited 2026 Feb 25]. Available from: https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/
12. Dhotre T, Thanawala S, Shah R. Optimizing Oral Vitamin C Supplementation: Addressing Pharmacokinetic Challenges with Nutraceutical Formulation Approaches—A Mini Review. Pharmaceutics [Internet]. 2025 Nov 11 [cited 2026 Feb 25]; 17(11): 1458. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC12655283/
13. Allison SJ. Ascorbic acid and risk of kidney stones. Nature Reviews Nephrology [Internet]. 2013 Feb 19 [cited 2026 Feb 25]; 9: 187. Available from: https://www.nature.com/articles/nrneph.2013.29
14. Alberts A, Moldoveanu ET, Niculescu AG, Grumezescu AM. Vitamin C: A Comprehensive Review of Its Role in Health, Disease Prevention, and Therapeutic Potential. Molecules [Internet]. 2025 Feb 5 [cited 2026 Feb 25]; 30(3): 748. Available from: https://www.mdpi.com/1420-3049/30/3/748
