Can vitamin supplements help maintain your vision?

Researchers from an international research group called the Cochrane Collaboration looked into the benefits of vitamin supplements for cataracts. They looked for special studies called randomized controlled trials that compared these products either with each other or with a fake supplement (placebo). They checked whether taking supplements could prevent cataracts or slow their progression.

The researchers analyzed nine studies involving a total of almost 120,000 people between the ages of 35 and 85. The participants used products with vitamin C, vitamin E and/or beta-carotene – that is, products thought to be especially good for your eyes – for up to twelve years.

The results of the studies clearly show that vitamin supplements are not effective against cataracts. People who had taken these products – in some cases for many years – developed cataracts just as often as people who had been taking a placebo. The supplements also didn't slow down the progression of the cataracts, and they didn't have any effect on eyesight. But some products had side effects: Depending on the study, between 7 and 16 out of 100 people who took beta-carotene had their skin turn yellowish-orange. This is a sign that they had taken too much beta-carotene.

Although vitamins are important for the body, a normal, balanced diet usually provides enough vitamins. So there's no reason to take dietary supplements to try to prevent or slow down cataracts. The Cochrane researchers considered the results to be so clear that they see no need for further research in this area.