Vitamin C

Vitamin C is a water-soluble vitamin, which means it can’t be stored by the body and needs to make up part of your diet every day.

It acts as an antioxidant, helping to protect cells against the damaging effects of free radicals, and it plays an important role in the absorption of iron.

Where can I get it?

The best way to get plenty of vitamin C is to eat your 5-a-day. An enormous range of fruit and vegetables contain this vitamin, such as blackcurrants, mangoes, strawberries, kiwi fruit, peppers, broccoli, Brussels sprouts, sweet potatoes, new potatoes and cauliflower are all good sources. Oranges are perhaps the most famous vitamin C-rich food and the fruit and juice are easy to buy.

There is a problem, though. Vitamin C is sensitive to air, water, and temperature. A large amount can be lost when food is cooked – between a quarter and a half of the total vitamin C content can be lost if food is cooked for up to 20 minutes.

You can minimise this by making sure your 5-a-day includes some raw fruit and veg. You could also quickly steam or stir-fry your vegetables instead of boiling them for several minutes to reduce vitamin C losses. A good tip is to consider whether you could eat the vegetable raw - if you can, there’s no need to cook it for long.

How much should I eat?

Unlike the fat soluble vitamins (A, D, E and K) vitamin C can’t be stored by the body so you need to eat some sources of it every day. Everyone has a different requirement, according to their age and health, as well as the quality of the rest of their diet.

Smokers should try to eat more vitamin C than non-smokers – more work is needed combating the free radicals generated by cigarette smoke.

It’s recommended that adults consume 40mg of vitamin C daily. A glass of unsweetened orange juice contains around this amount, as does a portion of cooked broccoli. A portion of stewed blackcurrants contains about three times as much.

As you can see, it’s very easy to get all the vitamin C you need from your diet. Supplements can be expensive and taking large amounts of vitamin C in supplement form can cause stomach pain, diarrhoea and flatulence. The Food Standards Agency says that taking 1000 mg or less of vitamin C supplements a day is unlikely to cause any harm but it’s also worth remembering that pills often contain extremely high amounts of the vitamin – and because the body can’t store it, it will just be wasted.

What does it do?

Free radicals are a type of molecule, created by the body for a number of reasons – sometimes they act in your favour as part of the immune response - and if they get out of hand the body can usually deal with them.

However, for various reasons the number of free radicals can sometimes overwhelm the body’s mechanisms for handling them, and that’s when they start to cause damage, mostly to the structure of cells. This might happen as a result of exposure to pollution in the environment or cigarette smoke, for example and, unfortunately, the damage they cause builds up as you get older.

It’s thought that vitamin C, along with other antioxidants including vitamin E, interferes with the harmful chain reaction set up by free radicals and can avert this damage.

Vitamin C also helps the body to absorb iron, which is needed to help the blood carry oxygen round the body.

The disease linked to vitamin C deficiency is called scurvy - generally thought of as a problem of the past. It causes tiredness, muscular and bone pains and depression. If it gets very bad, there’ll also be a problem with slow wound healing and bleeding gums.

Unfortunately, scurvy does still occur sometimes – perhaps if someone has an extremely poor diet as a result of low income, or when food intakes are exceptionally low, such as anorexia.

Vitamin C is linked to a healthy immune system and many people believe that taking large doses can ‘cure’ the common cold. Unfortunately, research into this popular debate is still inconclusive.