|Evan Watson, NatureCity author & contributor|
According to a study published in the December 2008 issue of The Journal of Geriatric Psychiatry and Neurology there may be a significant link between a lack of vitamin D and cognitive impairment in older adults.
The study included 1,766 participants (708 men and 1,058 women) over the age of 65. The participants all took part in the Health Survey for England (HSE) in the year 2000. The HSE is a national population-based survey conducted annually in the United Kingdom.
For the study, researchers from the University of Cambridge in the U.K. and the University of Michigan measured cognitive function using a common screening method called the Abbreviated Mental Test. This test measures important cognitive abilities that can decline with age like attention and time, space, and memory orientation.
The researchers then measured the blood levels of vitamin D among participants. After accounting for outside factors like age, sex and education they found that participants with normal cognitive function had higher levels of vitamin D than those with impaired cognitive function.
Perhaps more importantly, they also identified that participants with the lowest vitamin D levels were four times more likely to be cognitively impaired than those with the highest levels.
The researchers were able to determine a clear relationship between vitamin D levels and cognitive impairment. However, due to the study design they could not establish if low levels of vitamin D actually cause cognitive impairment.
Hopefully these results will trigger future studies that analyze the mechanism behind the relationship between vitamin D and cognitive function to answer this question.
Vitamin D is usually acquired through exposure to sunlight. But as you age your skin becomes less efficient at absorbing and metabolizing the vitamin.
This puts the elderly at particularly high risk of vitamin D deficiency which is associated with higher risk for osteoporosis, common cancers, autoimmune diseases and cardiovascular diseases.
A good way to avoid a vitamin D deficiency is to eat more foods fortified with the vitamin or to take a high quality nutritional supplement.