Vitamin D May Reduce the Risk of Age-Related Macular Degeneration.

Macular degeneration is a major cause of gradual central-vision loss in the elderly. The average age at onset of visual loss is about 75 years. After the age of 50 years, the incidence steadily increases; over one-third of people in their ninth decade of life are affected. Researchers suspect that certain conditions contribute to the disorder. Some of these are arteriosclerosis, oxidative damage, photic damage, inflammation, poor vs. good diet, vitamin and rare element deficiencies, and genetics.

Vitamin D is known as the "sunshine" vitamin because it is formed in the body by the action of the sun's ultraviolet rays on the skin. The fat-soluble vitamin is converted in the liver and ultimately the kidneys to active Vitamin D. Decreased vitamin D intake along with not enough sunlight exposure can cause a vitamin D deficiency. Other causes could be inadequate absorption and impaired conversion of vitamin D into its active form. When vitamin D deficiency occurs, bone mineralization is impaired which leads to bone loss. Rickets, osteomalacia, osteoporosis, Crohn’s disease and cancer are associated with vitamin D deficiency.

A study published in the Archives of Ophthalmology investigated the relationship between vitamin D and age-related macular degeneration (AMD) in participants of the Carotenoids in Age-Related Eye Disease Study. The researchers assessed AMD status and baseline vitamin D serum samples from 1,313 women. The results were an inverse association was found between higher intake of vitamin D with reduced risk of AMD by 59 percent in women younger than 75 years of age in comparison to women with the lowest intake. These findings suggest that high serum vitamin D concentrations may protect against early AMD in women younger than 75 years old. The study is published in the April 2011 issue of the journal Archives of Ophthalmology.