The nutrition team

Does your medical cabinet contain a veritable rainbow of nutrition supplements? If so, it’s likely that vitamin C is among them. Touted over the last 20 years by eminent scientists such as Nobel prize winner, Linus Pauling, as the miracle cure for the common cold, and more recently by the scientific community as a valuable anti-oxidant in the fight against cancer and heart disease - vitamin C can only be good, right?

Perhaps not.

A study, published in the scientific journal, Science, this month showed that Vitamin C had the capacity to increase the conversion of specific types of fats, believed to trigger cancer in the body, by damaging DNA. However, before you start clearing the pill bottles out of your cupboards, lets have a look at the study in more detail.

The study, conducted at the University of Pennsylvania in the U.S., was carried out in test tubes, not in the human body. The human body is a much more complicated environment of thousands of different chemicals, all working together. Therefore, translating findings from laboratory studies such as this one, to ‘real’ situations is not necessarily appropriate.

For example, in real life, vitamin E was found to prevent the very chemical reaction that the scientists in Pennsylvania showed that vitamin C promoted. Yet in the earlier work, vitamin C actually enhanced the effect of vitamin E. Therefore, it’s actually more likely that in the human body, vitamin C is beneficial in the fight against cancer rather than an added risk factor.

Furthermore, since vitamin C is a water soluble vitamin, it’s unlikely to react with the fatty substances used in this study. Water and oil don’t mix. Other studies show that vitamin C works as an anti-oxidant to ‘mop up’ free radicals that cause DNA damage and cancer growth in the body.

This study is not a good reason to stop taking enough vitamin C.

While supplementation is no replacement for a healthy diet, it is still vital to make sure you get enough vitamin C. As a basic requirement, we need it to prevent scurvy, which rarely occurs in the developed world today.

Now, we know that vitamin C may boost immunity and may protect against lifestyle diseases such as cancer and heart disease. The recommended intake per day is 60 mg, but smokers, diabetics and individuals who are undergoing major stress in their lives, such as an illness, may need more for optimal health.

The best sources are citrus fruits; an orange will provide 54 mg, a glass of orange juice gives 78 mg. At this time of the year, strawberries are a great source with 77 mg in an average serving.

Many vegetables contain vitamin C but one of the best, and perhaps surprising sources are peppers, with 48 mg in a quarter of a pepper. Many food manufacturers also use vitamin C as a preservative. Check the labels of processed foods for ascorbic acid, which is the scientific name for vitamin C.

If you are taking a supplement, check the label, some supplements contain as much as 1 gram (1000 mg) of vitamin C. This amount is unlikely to harm, but it’s far more than you need, and your body will just get rid of it. Since vitamin C is water-soluble, the body eliminates the excess in your urine.

Did you know?

The reason sailors are known as ‘Limeys’ today, is that they took citrus fruits, especially limes, on the ships to prevent scurvy on long journeys.