Taking large quantities of minerals and vitamins may affect the absorption of others. And no optimal ratios have been determined so far.So it's not just that taking lots of one thing is not good for you, it's that it may cause a dangerous reduction in something else even if you are also supplementing that.

The Risk Of Malnutrition

<ul><li>If you are healthy, and have a modern balanced diet, taking multi-vitamins and high-dose antioxidants may shorten your life.</li><li>There’s no evidence to support antioxidant supplements for primary or secondary prevention of diseases. </li><li>Beta-carotene and vitamin E seem to increase mortality, and so may higher doses of vitamin A. </li><li>Antioxidant supplements need to be considered as medicinal products and should undergo sufficient evaluation before marketing.</li><li>The functions of minerals and vitamins are understood largely by their deficiency diseases so there’s no certainty what they all do or how they interact. </li><li>Antioxidants soak up toxic, chemically-reactive by-products of metabolism called free radicals. These free radicals, left unchecked, can cause damage to DNA and may be linked to cancer.</li><li>Your body's immune system fights infections by using free radicals to kill bugs. Several of the minerals and vitamins in excess can cause damage.</li></ul>

Research Reviews’ Results

Looking at individual studies won't determine if vitamin supplementation is good for you. They're scientifically dense and the conflicts of interest can be very hard to spot."Systematic review papers" are much better suited for that. This is where independent scientists gather up all the available data and re-analyze it to answer big questions.

Individual Supplement Studies

<ul><li>Folic acid for the women thinking of having a baby and pregnant women up to week 12 of the pregnancy.</li><li>Vitamin D for all pregnant and breastfeeding women, those aged six months to five years or over 65 and for people who are not exposed to much sun.</li><li>Vitamins A, C and D supplementation are recommended for all children aged six months to four years, especially those not eating a varied diet. </li><li>If they are prescribed to you for a medical condition.</li></ul>

Supplement Usage Recommendations

Millions of people swear by vitamin supplements. But many are wasting their time and some could even be harming themselves, argues Dr Chris van Tulleken. In November 1912 a party of three men and 16 dogs set out from a remote base in eastern Antarctica to explore a series of crevasses many hundreds of miles away.