Vitamin D may boost eyesight

Combats the effect of ageing
Tue 17 Jan, 2012 01:00 pm GMT

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Vitamin D supplements may help to combat the effects of age-related eye disease, a study suggests.

Researchers said they hope the findings mean that vitamin D supplements could provide a simple and effective way to combat age-related eye diseases, such as macular degeneration (AMD).

AMD is the most common form of sight loss in the UK, affecting around half a million people. AMD affects the eye's retina and causes the loss of central vision, so the person is left with only side vision.

Lead researcher Professor Glen Jeffery, from the Institute of Opthalmology at University College London, said the blood vessels supplying the retina can become inflamed and accumulate debris as we age.

"In humans this can result in a decline of up to 30 per cent in the numbers of light receptive cells in the eye by the time we are 70 and so lead to poorer vision," he said.
However, when one-year-old mice were given vitamin D injections every three days for just six weeks, the researchers found that inflammation was reduced, the debris partially removed, and tests showed that their vision was improved.

The supplements led to a reduction in the number of macrophages in the eyes of the mice given the vitamin D. Macrophages are cells of the immune system which help to fight off infection, but in doing so, may cause tissue damage and inflammation, the researchers said.

The mice also had a reduction in deposits of a toxic molecule called amyloid beta, which is known to contribute to the risk of developing AMD in humans. Other blood vessels also showed a reduction in amyloid beta.

Professor Jeffery said: "Finding that amyloid deposits were reduced in the blood vessels of mice that had been given vitamin D supplements suggests that vitamin D could be useful in helping to prevent a range of age-related health problems, from deteriorating vision to heart disease.

"Researchers need to run full clinical trials in humans before we can say confidently that older people should start taking vitamin D supplements, but there is growing evidence that many of us in the Western world are deficient in vitamin D and this could be having significant health implications."

The research is published in the journal Neurobiology of Ageing.