The role of vitamin D in preserving cognitive function has been highlighted by a new study of post-mortem brains which found those of people with higher cognitive function before death contained higher levels of vitamin D.
The US researchers at Tufts University in Boston, whose study was published in the Journal Alzheimer’s & Dementia, measured vitamin D concentrations in 4 brain regions of 290 post-mortem patients who had agreed to be part of the project. The scientists reported higher levels of vitamin D were associated with 25% to 33% lower odds of dementia or mild cognitive impairment symptoms at the last patient visit before death. However, they also noted higher levels of vitamin D were ‘not associated with any decrease in post-mortem dementia neuropathology’ – and therefore could not suggest a mechanism for the potentially protective effect of vitamin D or show a causative link.
The scientists concluded ensuring individuals get sufficient vitamin D from sunlight and foods such as oily fish ‘might be beneficial, but warned against taking high doses of the vitamin to prevent dementia, as this can cause other health problems’, noted medicalnewstoday.com.
The scientists emphasised that by 2050, global dementia prevalence is projected to exceed 150 million, ‘representing a six-fold increase from 2019’ – hence there is ‘an urgent need for preventive strategies to reduce the burden of Alzheimer’s disease and dementia as the population ages’.
They summarised: ‘Evidence is accumulating that nutritional strategies play a key role in delaying or preventing the onset of cognitive decline and dementia, either through directly affecting neuropathology or by fostering resilience to pathology.
‘One nutritional factor that has received considerable attention is vitamin D, an essential fat-soluble vitamin and pro-hormone acquired through the diet and sun exposure… Several, but not all, epidemiological studies have associated low vitamin D intake with cognitive decline and dementia. Whether low vitamin D represents an independent risk factor for cognitive decline and dementia is controversial…The results of this study suggest that vitamin D in the brain may be involved in cognitive decline.’
