Friday, January 20, 2012. An article published online on January 2, 2012 in the journal Neurobiology of Aging reports an eye-rejuvenating benefit for a short course of vitamin D supplementation in aged mice.
Professor Glen Jeffery and his associates at the Institute of Ophthalmology at University College London supplemented old mice with vitamin D3 for six weeks while an untreated group served as controls. In addition to improved vision, the team found a reduction in number and changes in the configuration of retinal macrophages—immune cells that can sometimes cause excessive inflammatory damage—in animals that received the vitamin, as well as a decrease in retinal amyloid beta accumulation, which is a marker of aging. In humans, inflammation and amyloid beta accumulation are associated with an increased risk of age-related macular degeneration, a leading cause of blindness.
"In the back of the eyes of mammals, like mice and humans, is a layer of tissue called the retina," explained Dr Jeffery. "Cells in the retina detect light as it comes into the eyes and then send messages to the brain, which is how we see. This is a demanding job, and the retina actually requires proportionally more energy than any other tissue in the body, so it has to have a good supply of blood. However, with aging the high energy demand produces debris and there is progressive inflammation even in normal animals. In humans this can result in a decline of up to 30% in the numbers of light receptive cells in the eye by the time we are 70 and so lead to poorer vision."