Vitamin C is one of the most popular stand-alone vitamin supplements in the world and a 2002 report showed that next to multivitamins, Vitamin C was the most commonly consumed supplement in the United States. In South Africa, there are literally hundreds of different brands of vitamin C, which makes standing in the vitamin aisle a little overwhelming.
There is no doubt that vitamin C is important. Because it’s a water-soluble vitamin it cannot be stored and we need a constant and daily supply of vitamin C for normal growth and development. Vitamin C’s primary function is that of an antioxidant and quencher a variety of nasty free radicals that damage our DNA and essentially age us. Vitamin C is necessary for the formation of skin, scar tissue, tendons, ligaments, and blood vessels. Vitamin C is essential for the healing of wounds, and for the repair and maintenance of cartilage, bones, and teeth.
Much of the hype around vitamin C has to do with its role in preventing colds and flu, due to its immune boosting effects. However, the role that vitamin C plays in this regard is rather controversial. While there have been many studies that show that vitamin C supplementation can prevent and treat colds and flu, there are many studies that do not show this. A recent Cochrane database review of various studies relating to vitamin C and cold prevention showed that people who supplement with vitamin C as a prophylaxis (prevention) have shorter cold duration that people who did not supplement.
However taking vitamin C at the onset of a cold had no effect on cold duration. In addition it seems vitamin C supplements have little effect on cold symptom severity. So, there is still no cure for the common cold! One area where vitamin C supplements do show promise is in the prevention and treatment of pneumonia. So taking vitamin C during an upper respiratory tract infection could help prevent the infection from turning nasty. Studies have also hinted towards the use of high dose vitamin C supplements to help keep the HIV virus at bay.
Vitamin C’s role as a preventer of heart disease shows more promise. Vitamin C may help support the heart and vascular system by protecting against endothelial dysfunction, preventing heart attacks, and countering the dangerous oxidation of blood lipids. In one trial, men in the highest third of vitamin C intake had a 66% lower risk of coronary heart disease than men in the lowest third, after controlling for various other cardiovascular risk factors. Studies have also shown that supplementation with 700mg vitamin C per day reduces the risk of heart disease by 25%.
So how much vitamin C is enough? Ideally, we should be getting most of our vitamin C from dietary fruit and vegetable intake. The Food and Nutrition Board at the Institute of Medicine recommends a daily intake of 75mg vitamin C per day for women and 90mg vitamin C per day for men, which can be achieved by eating 5 servings of fresh fruit and veggies every day. However, most studies pointing towards vitamin C benefits use high dosages, which can only be achieved through taking supplements. From the studies, it seems that a daily dose of 250mg to 1000mg of vitamin C per day should do the trick. Larger dosages of up to 3000mg per day can be taken but only for a few days at a time. Taking larger dosages should only be done under medical supervision as it could even cause toxicity if maintained for extended periods. Look out for vitamin C supplements that also contain bioflavonoids, substances that enhance vitamin C absorption. Vitamin C in the form of Ester-C (a registered trademark) is also a good form to take the vitamin in.