There’s simply no substitute for a well-balanced, healthy diet

Vitamin and mineral supplements are no substitute for a healthy, well-balanced diet. Particular ones may also be hazardous if taken in excessive amounts or by those with medical conditions. A University of Hong Kong liver cancer study has found that antioxidants like vitamin C speed up the growth of cancerous cells. It is as much a reminder as a warning that doctors should be consulted on dietary changes.

With pharmacy and health-food store shelves bulging with supplements that do not need a prescription, paying to see a doctor may not seem necessary. The global nutrition and supplements market is booming in large part due to this ease of availability and Asia, with the least regulation, is the biggest growth area. Sales worldwide in 2013 were estimated by the Nutrition Business Journal at US$104 billion and rising at an annual rate of 6 to 7 per cent. It is all in the name of the search for the elusive elixir of youth or simply, better health and vitality.

There are numerous reasons why people reach for a bottle of vitamin or mineral supplements. Those with busy lives often find eating properly challenging. They know too much fast food or not enough fruit and vegetables are not good for health and well-being. Others may feel that they are lacking a particular vitamin or mineral in their diet. Nutritionists agree that a supplement is acceptable as a dietary addition if nutrient needs are not met.

But the university study shows that people with pre-existing health conditions need to be careful about what they take. It indicates that those with liver and perhaps other types of cancer could well find that self-prescribing supplements worsens their condition. It is also well recognised that taking too many vitamins or minerals, or ones that have a high content of a particular nutrient, could have serious health implications. The advice is that supplements are best used when recommended or approved by a doctor. But there is also a simple reality: that they should not be necessary if a diet that limits excess calories, fats, salt and sugar is eaten.