More evidence on vitamin D and macular degeneration

Consuming vitamin D from foods or supplements might reduce the risk of developing age-related macular degeneration (AMD) in women younger than 75, according to a study published this week by the Archives of Ophthalmology.

A team led by researchers at the University at Buffalo, N.Y., examined data on blood levels of vitamin D among 1,313 women 50 to 79 enrolled in the ongoing Women's Health Initiative study. In women younger than 75, vitamin D from foods and supplements—but not from time spent in direct sunlight—was linked with decreased risk of developing early age-related macular degeneration. Those who consumed the most vitamin D had a 59 percent decreased risk of developing it compared with women who consumed the least.

The researchers suggest that vitamin D might help regulate the immune system and perhaps help prevent diseases, such as AMD, that are linked to inflammation. The top food sources of vitamin D in the study were milk, fish, fortified margarine and fortified cereal.

Bottom line. This is the second study to find that vitamin D might help protect against AMD, the researchers said, but more research is needed. Meanwhile, the U.S. Centers for Disease Control and Prevention has just released national data on vitamin D status in the U.S. population, which found that 9 percent to 28 percent of females were at risk of vitamin D inadequacy and up to 12 percent were at risk of vitamin D deficiency.

Read more about good dietary sources of vitamin D sources of vitamin D. And if you decide to take vitamin D supplements, choose one labeled "USP Verified," which indicates that it meets standards for purity and potency set by the U.S. Pharmacopeia, a nongovernmental authority, and have what the USP considers acceptable limits of contaminants. For a list of products that have been verified by the USP, go to www.uspverified.org.

Sources
Vitamin D Status and Early Age-Related Macular Degeneration in Postmenopausal Women [Archives of Ophthalmology]

Vitamin D Status: United States, 2001-2006 [CDC]

—Doug Podolsky