A new study has found that taking high doses of vitamin D supplements may be associated with improved cognitive function in older adults with sleep disorders and mild cognitive impairment.
Researchers from Emory University conducted a study involving 54 adults with sleep disorders and mild cognitive impairment, with the aim of investigating the relationship between taking vitamin D supplements and cognitive abilities in this group.
The results showed that participants who took 5,000 IU or more of vitamin D daily scored more than 13% higher on the Montreal Cognitive Assessment (MoCA) compared to those who did not take vitamin D supplements. This association persisted even after accounting for other factors that could influence cognitive function.
The MoCA test is widely used to assess a number of cognitive abilities, including memory and reasoning skills, and it also helps monitor indicators of cognitive decline associated with dementia. However, the study found no clear link between lower vitamin D intake and improved test scores.
Victoria Buck, the study's lead author, said that the mild cognitive impairment stage may represent an important opportunity for intervention, explaining that changes in cognitive abilities begin to appear during this time, but there are still opportunities to support brain health
Buck added that identifying modifiable factors during the early stages of cognitive decline, including taking vitamin D supplements, may become increasingly important as Alzheimer's rates rise.
The study also found that the type of vitamin D was not associated with a difference in cognitive performance, whether it was vitamin D2, which is commonly found in some plant and fungal sources, or vitamin D3, which is produced by the body when exposed to sunlight and is also found in some animal foods.
Vitamin D plays important roles in the body, including supporting muscle and nerve function, and is also linked to sleep regulation and quality. Approximately half of those with moderate to severe Alzheimer's disease experience sleep disturbances, reflecting a correlation between sleep problems and cognitive decline.
Mild cognitive impairment is a stage between the normal changes in mental abilities that come with aging and dementia, and does not necessarily mean that a person will develop dementia. However, the study's findings suggest that this stage may be important for investigating modifiable factors, such as vitamin D levels, before cognitive decline develops.
The results are preliminary, as the study was conducted on a limited number of participants. Furthermore, it shows an association between vitamin D intake and cognitive performance but does not prove that supplements cause improvements in mental abilities. Larger studies are needed to determine whether taking high doses of vitamin D can actually improve cognitive function or reduce the risk of dementia.
