Researchers out of the University of Kentucky have found that low vitamin D intake may lead to brain damage as we age, according to results of their new animal study.
Vitamin D deficiency is common in older adults. As people get older, their skin becomes thinner. This limits the skin’s ability to synthesize vitamin D from the sun. This, paired with limited mobility and outdoor activity, further increases the risk of vitamin D deficiency among the elderly.
Cognitive decline is also common as we age. Might vitamin D deficiency play a role in this cognitive decline? Past studies have found that vitamin D deficiency has been associated with various cognitive disorders such as Alzheimer’s disease. One study, for example, found that higher vitamin D intake was associated with a decreased risk of developing Alzheimer’s.
Recently, researchers wanted to take a closer look at the relationship between vitamin D deficiency, aging, and cognitive decline and see if increasing vitamin D intake in rats slowed cognitive decline as they aged.
“Given that vitamin D deficiency is especially widespread among the elderly, we investigated how during aging from middle-age to old-age how low vitamin D affected the oxidative status of the brain,” said Dr. Allan Butterfield, who was involved in the study.
The researchers divided the rats into three groups:
- One group received 100 IU of vitamin D/kg of food
- One group received 1,000 IU of vitamin D/kg of food
- One group received 10,000 IU of vitamin D/kg of food
After being fed these diets for 4-5 months, the researchers found that the rats on the low vitamin D diets had higher levels of free radical damage to the brain and to various brain proteins. The rats on this low vitamin D diet also scored significantly lower on tests of learning and memory.
Dr Butterfield noted, “Adequate vitamin D serum levels are necessary to prevent free radical damage in brain and subsequent deleterious consequences.”
Keeney, J. T. et al. Dietary vitamin D deficiency in rats from middle to old age leads to elevated tyrosine nitration and proteomics changes in levels of key proteins in brain: Implications for low vitamin D-dependent age-related cognitive decline. Free Radical Biology and Medicine, 2013.