

Vitamin D and Memory Decline: A Possible Link?AD is the most common form of dementia in older individuals and affects approximately 5.2 million Americans. It is the 6th leading cause of death and costs approximately $148 billion year. The onset of AD usually occurs after the age of 65; however, it may begin earlier. Early-onset AD is usually caused by genetic mutations on three identified genes. Symptoms of AD include loss of cognitive and motor functions, which include short-term memory, vocabulary and organizational skills.
Vitamin D has been shown to have many different biological effects which positively influence health. A recent study set out of investigate a possible link between vitamin D and cognitive impairment. The researchers found that in 1766 adults aged 65 and older, higher vitamin D status was associated with lower cognitive decline, as measured on the Abbreviated Mental Test Score [AMTS]. The AMTS is a cognitive assessment survey that primarily measures attention, memory and orientation in time and space.
Subjects were divided into cognitively normal and cognitively impaired groups, based on the AMTS assessment . Those who were cognitively impaired were significantly older, were more likely to have less education and to consume higher amounts of alcohol compared to non-cognitively impaired individuals. Cognitively impaired subjects also had significantly [p < 0.001] higher rates of stroke and lower serum vitamin D concentrations. The relationship between cognitive decline and higher rates of stroke and lower serum D levels was stronger in men and was also associated with higher body mass index [BMI].
This study adds to a body of evidence regarding vitamin D and cognitive function. Vitamin D status is also associated with increased risk of cardiovascular diseases [CVD] which includes stroke as shown by the latest National Health and Nutrition Examination Survey [NHANES]. Furthermore, AD incidence is associated with higher cholesterol levels mid-life which also serves as a risk factor for CVD. This suggests that vitamin D, AD and variants of CVD may all be related. Further studies should look at possible mechanisms linking low vitamin D status to these diseases.


