Vitamin C, also known as ascorbic acid, is arguably the best-known immune-boosting vitamin and critical for the normal functioning of the body.

Boost your health with vitamin C

Vitamin C promotes resistance to infections like colds and flu, aids wound healing, is essential for the production of collagen (a type of protein that connects and supports other bodily tissues such as skin, bone, tendons, muscles and cartilage), enhances iron absorption and fights cataracts by increasing the amount of blood flow to the eye.

Vitamin C is also known as a powerful antioxidant which helps to protect cells from damage caused by free radicals that could contribute to the development of cardiovascular disease, cancers and other diseases.

As it’s a water-soluble vitamin, our bodies unfortunately don’t have the ability to make their own vitamin C or store it. We therefore need to fuel up with vitamin C every day to ensure that we don’t have a deficit.

You’re likely to suffer from vitamin C deficiency if you smoke, are exposed to pollution, drink caffeine in any form, are under stress, are recovering from illness or surgery, take aspirin regularly or are over the age of 55. If you bruise easily, are susceptible to infections and colds, lack energy, have gums that bleed easily and have nosebleeds regularly, it’s likely that you need more vitamin C.

The recommended dietary intake (RDI) of vitamin C is 45 mg/day. It is best to take the vitamin naturally from food sources.

Though oranges are a well-known source of vitamin C, you may be surprised to learn they are not the number one source of this vitamin. Have a look at our list of top 10 foods with vitamin C and start reaping the benefits.

1) Guava

Number one on our list is the guava. This sub-tropical superfruit contains about four times the amount of vitamin C as an orange. It’s also rich in vitamins A, folic acid and the minerals potassium, copper and manganese. It's also a great diet food as it is high in fibre and low in saturated fat, cholesterol and sodium.

The vitamin C content of guava is 200mg per 100g, so boost your immune system by upping your guava intake.

2) Blackcurrants

Though blackcurrants are listed in second place, they are right up there with guavas. They also contain 200mg of vitamin C per 100g; or four times the vitamin C content of an orange.

These berries are rich in antioxidants and flavonoids and help to relieve inflammation as well as urinary tract infections. They are also a good source of potassium.

3) Capsicum

Capsicums, especially red capsicums, are among the best sources of dietary vitamin C and high in antioxidant levels.

Red capsicums are the sweeter and riper versions of green capsicum and contain almost double the vitamin C content of green capsicum.  Raw red capsicums boast a whopping 140mg of Vitamin C/100g, whereas raw green capsicums, contain a very respectable 80mg of vitamin C/100g. When cooked, the vitamin C level is slightly lower.

Also known as sweet peppers, capsicums are low in kilojoules and a good source of vitamin B6, iron and potassium.

4) Broccoli

Broccoli has been hailed as a super food that boosts the immune system and helps to fight cancer. It is packed with vitamin C (89mg of vitamin C per 100g), and is also rich in beta-carotene, carotenoids, B vitamins (including folate), calcium, zinc and fibre.

Broccoli should only be boiled or steamed very briefly; otherwise it can lose a major portion of its beneficial components.

5) Strawberry

The popular strawberry is full of fibre and antioxidants and graces the fifth position with 80mg of vitamin C per 100g.

Did you know that strawberries are the only fruit that wear their seeds on the outside? It is argued that for this reason, it cannot be considered a real berry, since berries carry seeds on the inside.

Strawberries should be eaten when fresh, as their antioxidant values as well as their vitamin C content drops the longer they are kept.

6) Kiwi

The small kiwifruit is one of the world's most nutritious fruit and contains very high levels of vitamin C (70mg/100g), potassium, antioxidants and omega-3 fatty acids.

Kiwifruit should be eaten as soon as they are ripe, and sliced just before being eaten, as leaving them standing could decrease their vitamin C levels.

Did you know that the kiwifruit originated in China and is also known as the Chinese gooseberry? When, in the early 20th century, this small fruit was introduced to and grown in New Zealand, this country's exporters renamed it to kiwifruit - after the kiwi, a brown flightless bird and New Zealand's national symbol.

7) Papaya

The papaya (paw paw) provides 62mg of vitamin C per 100g serving. It is also a great source of other antioxidant nutrients such as carotenes and flavonoids; and vitamin A and folate. Papaya is thought to bring about a reduced risk of colon and cervical cancer.

This tropical fruit also contains the enzyme, papain, which is an excellent aid to digestion and can assist our body's enzyme to extract the maximum nutritional value from the foods we eat.

8) Brussel Sprouts

Brussel Sprouts may be the one vegetable kids of all ages love to hate, but if you can get used to their slightly bitter taste and learn not to overcook them, they offer some great health benefits.

Brussel sprouts contain beneficial phytochemicals, have anti-cancer effects and are a good source of folate, iron and vitamin C (60mg/100g).

It is best to steam or briefly boil Brussel Sprouts in order to preserve both the folate and the vitamin C. This way they'll taste much better too.

9) Orange

Enter the orange, in ninth place. The orange, together with other citrus fruit, is probably the best known source of vitamin C - as a winter fruit it is a great weapon against winter colds and flu.

The orange's vitamin C content is 50mg/100g and is known to boost the immune system and thought to reduce the risk of certain cancers. Citrus fruit  can also improve blood circulation and lower blood cholesterol levels. It is good to keep in mind that it's more beneficial to eat the fruit than only drink the juice.

10) Cauliflower

Cauliflower belongs to the same family as broccoli and Brussel sprouts and has a vitamin C content of 46mg/100g (raw). It contains several anti-cancer phytochemicals, B vitamins (including folate) and vitamin K.

As with broccoli and Brussel sprouts, it is best to steam or boil very briefly, as cooking greatly reduces its nutritional properties.

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