Vitamin C is a water-soluble vitamin that you can only get through your diet. It's good for your skin, bones and blood vessels. Vitamin C also supports your immune system, protecting you from infections — like the common cold.
- What is vitamin C?
- What does vitamin C do?
- How much vitamin C do you need?
- What foods contain vitamin C?
- What can cause vitamin C deficiency?
- What are the symptoms of vitamin C deficiency?
- How to improve vitamin C levels
What is vitamin C?
Vitamin C, also known as ascorbic acid, is a water-soluble vitamin — a type of nutrient. Your body can’t make vitamin C so you must get it from your diet. You also can’t store vitamin C so you must continually get enough from your diet.
What does vitamin C do?
Vitamin C has many important functions in your body. Firstly, vitamin C is needed to produce a structural protein called collagen. Collagen is a type of protein that makes up an essential part of connective tissue — found in your skin, blood vessels, ligaments, bones, cartilage, and so on. And because of this, vitamin C is important for proper wound healing.
Vitamin C is also a powerful antioxidant, which helps protect your cells against damage from oxidative stress. Oxidative stress has been linked to chronic diseases like cancer and heart disease, so a high intake of antioxidants might help protect against these. Vitamin C might also help regenerate other antioxidants in your body, like vitamin E.
Vitamin C has also been shown to build-up in immune cells called phagocytes, possibly enhancing their function. These are cells that ingest and destroy something that’s harmful, like bacteria and viruses.
Vitamin C also helps increase the absorption of calcium and non-heme iron (the type of iron in plant foods) in your body.
How much vitamin C do you need?
The recommended amount of vitamin C is 40 mg a day for adults aged 19-64 years — equivalent to about an orange a day.
What foods contain vitamin C?
Good sources of vitamin C include:
- kiwis — particularly gold kiwifruit
- citrus fruits — like oranges, lemons, and satsumas
- dark leafy greens — like spinach and cabbage
What can cause vitamin C deficiency?
Not having enough vitamin C as part of your diet is the main cause of low vitamin C levels — as your body can't make it. But a deficiency is quite uncommon. You might develop a mild deficiency if you follow a poor or very restricted diet.
What are the symptoms of vitamin C deficiency?
Symptoms of low levels of vitamin C include:
- fatigue (low energy and motivation)
- muscle and joint aches
- bleeding gums
Vitamin C deficiency has also been linked to a weakened immune system, increasing your susceptibility to infections.
Extreme cases of vitamin C deficiency is called scurvy.
How to improve vitamin C levels
A balanced and varied diet should provide you with all the vitamin C you need.
If you do take a vitamin C supplement, don't take too much as this could be harmful. Less than 1,000 mg of vitamin C supplements a day is unlikely to cause any harm. If you take more than this per day, it can cause stomach pain, diarrhoea, and flatulence. It’s always a good idea to speak to your pharmacist or GP before starting any supplement.
Hemilä, H. (2017). Vitamin C and infections. Nutrients, 9(4), 339.
National Institute of Health (2020). Office of dietary supplements. Vitamin C: Fact sheet for health professionals. Retrieved 17 March 2020 from https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/.
National Health Services (2017). Vitamins and minerals: Vitamin C. Retrieved 17 March 2020 from https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-c/.