Zinc is a trace mineral thought to improve a number of medical conditions including the common cold. Studies have shown it can help with healing wounds such as burns or leg ulcers. Zinc is also believed to be important for vision because it is found at relatively high levels in the macula and enables vitamin A to create the pigment melanin which helps absorb light.
Zinc has also been approved by the European Food Standards Agency for the claim 'Zinc contributes to the maintenance of normal vision'.
Zinc supplements can cause gastrointestinal effects, including abdominal pain, indigestion, nausea, sickness and diarrhoea. This usually occurs when supplements are taken on an empty stomach but is one of the reasons AREDS2 looked into the effect of lowering the dose. Because there was no statistical different in effect between the higher and lower dose we have chosen to use 25mg of zinc in our products for greater reassurance.
Long term use of high doses of zinc can result in reduced levels of copper and this is why copper is included in the AREDS2 formula.
Copper is not thought to have a direct effect on macular health. However, zinc supplementation can lead to copper deficiency. In turn, copper deficiency can affect the body's absorption of iron and so lead to anaemia. Therefore, copper is included the resolves these two issues.