VITAMIN LEVELS are markers of good health, not makers of good health

THE CASE

According to Research Australia's annual public opinion poll on health and medical issues, more than half the population took multivitamins in the last year to help combat a lack of energy. Courier Mail 20/01/2008

The marketers of nutritional have done a remarkably good job in selling a product there is no real need for. Some studies on vitamins have been recently received the attention in the media.

Vitamin E for vim and vigour

Vitamin E may help elderly people keep their vim and vigour, researchers have said. The researchers measured levels of certain vitamins in the blood of 698 people ages 65 and up in Italy and then used three tests - a short walk, balance and standing up from a seated position - to gauge their physical functioning. They found that volunteers with lower levels of vitamin E performed worse on these physical tests than those with higher levels of the vitamin. -SMH 23/01/2008

and

Vitamin C a stroke saver

A person's level of vitamin C may predict his or her likelihood of having a stroke, according to a long-term study of some 20,000 middle-aged and older residents of Norfolk, United Kingdom. During an average follow-up of 9.5 years, 448 strokes occurred in the study population. Researchers found that people with the highest vitamin C concentration at the start of the study had a 42 per cent lower risk of stroke over 10 years compared to those with the lowest levels of vitamin C. -SMH 23/01/2008

Proponents and purveyors of artificial supplements will no doubt grab these headlines and results and use them in their blurb - "Take vitamin E to keep fit and live longer." and "Take vitamin C to prevent strokes."

It just does not work like that. The logic is faulty, just because higher levels of a particular substance are found in people with good health, it does not mean that increasing the intake of said substance will cause good health. It just might, but there is no proof. It would be equally logical to conclude that strokes cause low levels of vitamin C. There is no evidence that either variable is dependant of the other, they both may be results of a third, unknown factor. What these studies really mean is that if you have high levels of vitamins in your blood stream, you probably eat a good healthy mixed diet.

Vitamin levels are markers of good health, not makers of good health.

Neither study recommended the use of artificial supplements. Except in the case of true deficiencies, the advocacy of nutritional supplements is an abuse of science.

The Vitamin C study said the level of vitamin C in the blood is a

"good biomarker of fruit and vegetable consumption, which have many nutrients that may be biologically active and protective for stroke; this study supports the existing body of evidence that indicates the high fruit and vegetable consumption is protective for stroke".

"Because we do not know why or how the benefit occurs or what fruits and vegetables are effective, it is prudent to consume a wide variety" ....."The optimum intake for reduction of stroke and cardiovascular disease is unknown"..... "but an intake of 5-9 servings daily is associated with benefit and the public should aim toward the higher intakes."

Studies showing benefits of the consumption of artificial nutritional supplements are, not surprisingly, thin on the ground. For example almost every study on the use of vitamin C to prevent or ameliorate colds and flu has proven there is not effect - nothing! Not even at 4 grams a day!

Sometimes vitamin supplements can even do harm. Folic acid is a B group vitamin essential to human growth and good health. Deficiencies can cause birth defects (neural tube deficits) and pernicious anaemia. Pregnant women must have adequate folic acid in their diets. But there is a balance. Cancers may need folic acid for growth, in fact some types of cancer chemotherapy (the antifols) depend on destroying cancer cells ability to use folic acid. Bearing this in mind, it is not surprising that there is some evidence that the unwarranted use of large doses folic acid may lead to an increase in cancer risk.

MY VERDICT

When you take a supplement, you take that substance in isolation. When you eat it, it is in a chemical context of the hundreds of other nutrients in that foodstuff. Evolution has fitted perfectly to deal with and take benefit from food. We have not evolved to need vitamin tablets.

I'll write it again, despite what the proponents and pushers of nutritional supplements say, vitamin levels are markers of good health, not makers of good health.

Don't waste your money - got to go now it's time to take my vitamins.