Do we really need all those vitamin and mineral supplements?

Date:22 October 2014 Tags:,

We all want to be healthy and live forever (or at the very least, prove the insurance company’s actuaries wrong by a country mile). Some of us try to achieve optimum health by taking regular physical exercise and eating healthy food – an entirely sensible approach that has yet to be convincingly challenged – but many people believe our food and our environment have changed to such an extent over the years that we have no choice but to go the route of dietary supplements for the essential vitamins and minerals our bodies require. Yes, but do we really need all those pills?

In 1911, Polish Chemist Casimir Funk made one of the most influential biomedical discoveries of all time. He learnt that a disease called beriberi affected those who ate a diet of mainly white rice, but not those who ate mostly brown rice. He isolated a chemical from rice bran, showed it could prevent beriberi, and called it “vitamine”.

We now call that compound vitamin B1. It is one of many essential nutrients that the human body cannot produce in sufficient quantities, and that we must obtain from food. Casimir’s breakthrough led to similar discoveries, including the compounds that prevent scurvy and rickets. In 1920, the British chemist Jack Cecil Drummond proposed dropping the “e” and using the umbrella term “vitamin”.

Early success at identifying, preventing and curing nutritional deficiencies naturally led to the idea that dietary supplements were good for everybody. Science now recognises around a dozen essential vitamins, as well as some 20 minerals considered essential in small amounts. In the US, iodine was added to table salt in 1924 to prevent goitre, vitamin D to milk in 1933 to prevent rickets, and several vitamins and minerals were added to flour in 1941.

Public awareness of vitamins grew, and with it, a desire to take personal control. Single vitamin supplements became available in the US in the 1930s, and multivitamins went on sale a decade later.

Though health authorities emphasise that most of us should be able to get all of the vitamins and minerals we need from a balanced diet, the industry has boomed. The list of supplements now numbers in the hundreds. It is estimated that about half of the US population now takes some form of supplement each day, while nearly a third of people in the UK do the same. All those pills and powders add up: the industry is worth roughly R320 billion in the US, and some R11,8 billion in the UK.

But in recent years, doubts have emerged over whether these supplements actually work, and whether they are always safe – particularly when they supply vitamins that can slowly build up to dangerously high levels in body fat.

PM looks at the latest evidence for and against the 20 most popular in the November 2014 issue.