Vitamin D plays an important role in maintaining bone health, but a new study led by University of Kentucky researchers claims that deficiency of this vitamin may cause damage to the brain and other organs.

The results, published in Free Radical Biology and Medicine, showed that when middle-aged rats were fed a diet low in vitamin D for several months, they developed free radical damage to the brain. They also performed less well in cognitive functioning tests for learning and memory.

The researchers say that several brain proteins were found to have significantly higher levels and that this contributes to significant nitrosative stress in the brain, possibly leading to cognitive decline.

The researchers claim that vitamin D deficiency is increasing in the US and its effects on an aging brain should not be underestimated.

Prof. Allan Butterfield, lead author of the paper, explains:

"Given that vitamin D deficiency is especially widespread among the elderly, we investigated how, during aging from middle-age to old-age, low vitamin D affected the oxidative status of the brain.

Adequate vitamin D serum levels are necessary to prevent free radical damage in brain and subsequent deleterious consequences."

Catch some rays

Often called the "sunshine vitamin," dietary sources of vitamin D are limited, and the study notes that when times are hard, individual food intake is not always the most nutritious.

The result of this is low levels of the vitamin, particularly among the elderly population. Coupled with the widespread use of sunscreens and popularity of wearing of long-sleeved clothing in the sunshine, levels of vitamin D are declining.

Low levels of vitamin D have previously been linked to Alzheimer's disease, the development of certain cancers and heart disease.

Prof. Butterfield recommends that everyone should allow themselves at least 10-15 minutes' exposure to sunshine every day to ensure that vitamin D levels are adequate.

He also suggests that vulnerable people should contact their physicians to have their levels tested. If they are low, individuals should consider taking supplements and eating more foods containing the vitamin, including oily fish, eggs and fortified milk.

Medical News Today recently reported that dancers from Birmingham's Royal Ballet in the UK have benefitted from vitamin D supplements, citing a report that showed greater improvements in muscle strength and fewer injuries for dancers taking them.

However, researchers from Johns Hopkins caution that too much can do more harm than good. Levels over 21 nanograms per milliliter increased levels of c-reactive protein, which is associated with hardening of blood vessels and an increased risk of cardiovascular problems.