Boosting vitamin D intake could significantly improve the vision of elderly people, a study has revealed.

British researchers discovered that vitamin D supplements have the potential to effectively fight age-related eye diseases, such as macular degeneration.

By the time a person reaches the age of 70, the number of light-receptive cells in the eye decreases by up to 30 percent, which leads to poorer vision, said Prof Glen Jeffrey, a neuroscientist at the Institute of Opthamology, University College London, which conducted the study.

Another problem experienced by the elderly is that tiny blood vessels that supply the retinas become clogged with debris over time and also become inflamed, Professor Jeffrey explained.

Although middle-aged mice were used in the study, the research scientists believe the findings could have important implications for human health, as effects were observed in the mice in as little as six weeks.

The scientists believe many people in developed countries lack vitamin D, which they think is essential to keeping a good supply of blood flowing to the retinas, and that the use of supplements may be a "simple and effective way" to counter the condition.

However, the Royal National Institute of Blind People (RNIB) warned that considerably more work was required before people started taking supplements to help with deteriorating vision.

Jeffrey said: "Researchers need to run full clinical trials in humans before we can say confidently that older people should start taking vitamin D supplements."

But he acknowledged there was growing evidence that many people in the West were deficient in vitamin D, which could be having significant health implications.

RNIB spokeswoman Clara Eaglen told the Telegraph: "It is important to remind people that this is a trial."

"Anyone thinking about taking vitamin supplements should consult their doctor. Taking high levels of supplements can cause other health problems."