Vitamin C – it’s the vitamin we’ve all heard of and we all know we need it in our diet to stay healthy. But what does it actually do and why do we need it?
Vitamin C is an essential nutrient. It cannot be made in our bodies and must be obtained in our diet. Only very limited amounts of Vitamin C can be stored in the body and these stores get used up quickly if Vitamin C containing food isn’t eaten. We need an ongoing supply of it.
Vitamin C is used in many processes in the body. It is involved in tissue growth and repair, helping wounds to heal and scar tissue to form. It helps enzymes to function and is very important in keeping our immune system working well. Vitamin C helps our bodies absorb iron from food and also helps our thyroid gland make thyroxine. Another very important function of Vitamin C is the maintenance of collagen levels. Collagen is a protein vital in forming our skin, tendons, ligaments, bones and blood vessels. Without Vitamin C, the collagen in these tissues becomes weak and unstable and cannot function properly.
Vitamin C is also an antioxidant. Antioxidants protect the cells in our body from damage caused by free radicals. Free radicals are made when our bodies break down food, inhale cigarette smoke or are exposed to radiation. Free radicals can build up over time and contribute to the aging process.
Some people are more likely to be low in Vitamin C. Smokers, pregnant women, people on certain medications such as oral contraceptives, people who drink regularly and people with kidney failure often have higher Vitamin C needs.
Signs that may indicate that you are low in Vitamin C are tiredness, skin that bruises easily, bleeding gums and constantly getting colds.
The best way to get your recommended intake of Vitamin C is from uncooked fruit and vegetables. The Ministry of Health recommends the daily intake for adults should be 45mg. Infants and children require less (25mg to 40mg), while pregnant and breastfeeding women have higher needs (55mg to 80mg a day). If you have a well-balanced diet that includes at least five servings of fruit and vegetables a day, it is likely that you are getting enough Vitamin C, around 200 to 400mg. Foods high in Vitamin C are fruits such as citrus fruit, kiwifruit, strawberries, blackcurrants, mango, papaya and pineapple, and vegetables such as broccoli, Brussels sprouts, capsicums, kale, potatoes, kumara and tomatoes.
Cooking and storing fruit and vegetables for a long time can decrease the amount of Vitamin C in foods. Microwaving and steaming can help to minimise cooking losses.
Vitamin C has long been available in supplement form. There has been much debate over whether taking it as a supplement is of any benefit, as any excess of Vitamin C in the body is not absorbed and gets excreted in the urine. For those that find it difficult to eat a balanced diet, or who place extra stresses on the body such as smoking, a supplement could prove beneficial.
There have also been many studies trying to find out the role Vitamin C plays in the prevention of colds. It appears that taking a Vitamin C supplement once you have a cold isn’t helpful, and for most people, Vitamin C doesn’t decrease the risk of getting a cold. However evidence does suggest that regular users of Vitamin C may have shorter colds or milder symptoms.
If you decide that Vitamin C is a supplement for you, the recommended dosing is around 500mg to 1000mg per day. Large doses (2000mg to 3000mg) taken on an empty stomach can cause nausea, indigestion, abdominal cramps and diarrhoea. Taking a supplement in the form of sodium ascorbate or calcium ascorbate can minimise stomach effects. Talk to your local pharmacist about the best form of Vitamin C supplement that is suitable for your needs.