Nutrition can be a minefield, so no wonder many people take vitamin and mineral supplements to make sure they're getting all the nutrients they need. But a new report from consumer organisation Which? suggests many vitamin products available in the UK today are labelled with misleading or insufficient information. Some, claims Which?, could even be harmful.
After visiting a range of supermarkets, chemists and health shops in London last October, Which? researchers found a number of examples of vitamin products that promised a range of health benefits - few of which had actually been substantiated.
They also claim to have found a number of supplements with potentially unsafe levels of vitamins and minerals - including some containing vitamin B6 and beta-carotene, for example - that didn't print warnings on the label that taking too much of them could be harmful.
And that, they say, is particularly worrying, since they also conducted an online survey of more than 1,200 vitamin pill takers in the UK, and discovered a third didn't realise taking too much of certain supplements could damage your health.
Beta-carotene, for instance, is converted in the body to vitamin A, which can be a risk for pregnant women in high doses. Other side effects of supplements include diarrhoea (in vitamin C doses of more than 1g), stomach upsets (high doses of calcium), constipation (iron) and nausea (zinc).
In the article, published in the January 2011 issue of Which? magazine, Cath Collins, chief dietician at St George's Hospital, London, explains that there hasn't been enough study of the effects of long-term intake of supplements.
What do you think about vitamin supplements? Are they useful or dangerous?