Vitamin C: benefits, sources, and deficiency

What is vitamin C?

Vitamin C, also called L-ascorbic acid, is an essential nutrient we all need for good health. This vitamin supports many important functions in our bodies and helps to maintain our blood vessels, bones, and skin.

Benefits of vitamin C

As vitamin C plays a role in the health and maintenance of so many organs and systems inside us, the list of vitamin C benefits is an extensive one. Here are some of the most important rewards you can get from consuming enough of this super vitamin.

Protection against disease and illness

Vitamin C may help to ward off certain illnesses and long-term diseases in several ways¹:

• It's an antioxidant that helps to fight inflammation and widens your blood vessels - this can reduce the risk of associated diseases like high blood pressure.

• It protects against free radicals - these are harmful molecules in the body that can damage cells. Free radicals have a role to play in the development of conditions such as cancer and heart disease.

• It boosts the immune system - helping your body to fight a range of illnesses.

Wound healing

Vitamin C is used by our bodies to produce collagen, an important structural protein in our skin, muscles and bones. One of the ways in which collagen keeps us healthy is by promoting wound healing², helping to mend injuries that break the skin and other body tissues while protecting us from infection.

Strong and healthy skin and bones

Vitamin C benefits also include the general health and strength of our skin and bones. In the skin, its antioxidant properties and role in collagen production helps protect against skin ageing and other skin complaints - this is why you'll find vitamin C in many skincare products. As an anti-inflammatory, this vitamin can also help to prevent inflammatory arthritis and may support people with osteoarthritis³.

Iron absorption

This nutrient helps our bodies absorb another vital nutrient - iron. We need iron for growth and development, and when we don't absorb enough we may experience weakness, fatigue, and problems with memory and concentration. This health issue is called iron-deficiency and it can lead to long-term complications if left untreated⁴.

Good sources of vitamin C

We get the vitamin C we need through the food we eat. It's a water-soluble vitamin, meaning that once inside us it dissolves in water and is delivered straight to the body's tissues, but we are unable to store it. For this reason, we need to consume foods with vitamin C content every day in order to stay healthy.

You can also take daily vitamin C supplements to bolster your vitamin C levels. However, remember that a dietary supplement is only good for you when taken in addition to - and not instead of - a healthy, nutrient-rich diet.

Patient picks for Healthy eating

How much red meat should you eat?

We should all know that just as fruit and veg are good for us, so refined carbs, including sugar, are bad for us - there's basically no exception to this rule. But along with this well-evidenced mantra, there are other new "food rules" - and some of them seem to be more knee-jerk reaction than carefully considered guidance. Public Health England came under fire in 2017 for its campaign on acrylamide after the true (tiny) size of the risks it was warning against, became apparent. But the advice to reduce intake of red and processed meat combined to under 70 g a day resulted in no similar backlash. Here we look at the evidence and ask if there's more to this advice than 'meets' (no pun intended) the eye. new

How much vitamin C per day?

"Adults need 40 milligrams (mg) of vitamin C per day⁵," says Patel. "This is usually easy to get through your diet. For example, one medium orange has around 70-80 mg of vitamin C and two kiwis provide more than 130 mg of vitamin C."

However, certain people are more at risk of not getting enough vitamin C through food alone. This makes them more vulnerable to the health problems associated with vitamin C deficiency.

Vitamin C deficiency

Not getting enough vitamin C persistently, usually over a period of three months or more, is known as vitamin C deficiency. The following groups have a higher risk of this condition:

• People with a dependency on alcohol or other drugs who may also have a poor diet.

• People on very restrictive diets.

• People who smoke regularly.

• People with a medical condition that inhibits healthy digestion and absorption of food, such as Crohn's disease.

• Older people who eat a less varied diet.

• Pregnant and breastfeeding women as they need higher doses of vitamin C.

Vitamin C deficiency can lead to scurvy, although Patel adds that the likelihood of developing scurvy in the UK is very low.

She describes the common symptoms of scurvy:

• Fatigue.

• Bleeding and swollen gums.

• Sore joints.

• Delayed wound healing or easy bruising.

• Nosebleeds.

• Low mood.

Can you have too much vitamin C?

Just as it's possible to not get enough vitamin C, you can also consume too much - although this isn't an easy thing to achieve through food alone. Large doses of vitamin C - that exceed 1000mg a day - are most likely the result of taking too many vitamin C supplements. If supplementing, make sure you're not taking more than 75 mg a day for a women and more than 90 mg a day for a man.

Too much vitamin C can lead to side effects such as diarrhoea and stomach pain. While uncomfortable and inconvenient, these symptoms tend to be temporary, disappearing once supplementation in large doses is stopped.

Further reading

1. National Institutes of Health: Vitamin C.

2. Mathew-Steiner et al: Collagen in wound healing.

3. Ripani et al: Vitamin C may help to reduce the knee’s arthritic symptoms.

4. National Institutes of Health: Iron.

5. British Nutrition Foundation: Vitamins and minerals.