Food supplements are dietary additions intended to supplement the food we eat. The European Commission has established rules for the whole of the EU relating to supplements containing vitamins and minerals. Maximum and minimum amounts are being set for every vitamin and mineral approved for use.
The European Food Safety Authority was asked by the EU to investigate safety and bio-availability of supplements. They are establishing upper tolerable levels for supplements and looking into the way in which the supplements are taken up by the body.
Check out the EFSA website to read about the good work being done