April 11, 2011 -- Warding off vision loss in old age may have more to do with what's in your kitchen than what's in your medicine cabinet. According to new research published Monday, women who consume high levels of vitamin D through certain fish, dairy and eggs could lower the risk of macular degeneration, the leading cause of vision loss in later life, by 59 percent.
Many women must resort to using reading glasses as they age, but for Dorrette White, 47, the blurriness at the center of her vision was something more. After a routine visit to her eye doctor, this Brooklyn mother of four was told she was in the early stages of age-related macular degeneration (AMD), a leading cause of vision loss and blindness among older Americans that strikes 8 and half million Americans.
When she first heard the news, she worried "that it's like months down the line you'll go blind or something like that," White said.
Fortunately for White, her condition is unlikely to lead to blindness any time soon, and for now her only "prescription" is a healthy lifestyle complete with lots of vitamin D-rich foods, said her ophthalmologist, Dr. Shantan Reddy. Reddy has prescribed her a healthy dose of vitamin D-rich foods.
"She's got very early signs…and most of these patients don't progress to more advanced types. But to decrease risk further, I recommend her adding vitamin D rich foods," said Reddy, who is an assistant professor of Ophthalmology at NYU Langone Medical Center.
In Monday's study, women who consumed the most vitamin D cut their risk of developing early AMD by more than half when compared to women with vitamin D-poor diets. Researchers found that risk was lowest when patients consumed 720 international units of Vitamin D per day through foods such as cold water fish, eggs, and dairy.
A little over three ounces of blue fin tuna would meet the daily dose, for example.
Vitamin D as Medicine
Reddy said the findings are "wonderful" because currently there are "limited treatment in preventing the progression of macular degeneration and…no established means to prevent its occurrence. With this study we know there are vitamins that you can take through your diet that can decrease the odds of developing [it]."
"We can hit the problem before it even begins," he said.
Though vitamin D can be obtained from foods, supplements, or by exposure to the sun, researchers found that vitamin D levels among patients in the study were most affected by the amount of vitamin D they consumed, not by the amount of outdoor exposure they had.
"This study found that women who are deficient in vitamin D based on their serum levels (< 30 nmol/L) may be at increased risk for AMD. However, having very high blood levels of vitamin D does not impart any additional benefit with respect to AMD. This study may offer one more reason for women to include vitamin D-rich foods in the diet (milk, fortified cereal, fish)," said the lead author on the study, Amy Millen of the University of Buffalo.