There appears to be a direct link between vitamin D levels and the cognitive diseases, say researchers at the University of Exeter. Dr David Llewellyn, the research team leader, said he expected to see an association between low vitamin levels and dementia risk, but was surprised by the findings. "We actually found the association was twice as strong as we anticipated," he said.
They tracked the health of 1,658 older adults who didn't have dementia or Alzheimer's at the beginning of the trial. By its end, nearly six years later, 171 had developed dementia, including 102 with Alzheimer's-and it had affected those with the lowest levels of vitamin D in their blood.
Those who were moderately deficient in vitamin D had a 53 per cent increased risk of developing dementia, but those who were severely deficient ran a risk of 125 per cent. Conversely, those with the highest levels of the vitamin also had the least risk for dementia.
Vitamin D levels can be easily topped up by being out in the noon-day sun during the summer months for at least 15 minutes three times a week. During the winter, and especially in northern climates, vitamin D levels can be topped up by eating oily fish or taking supplements.
(Source: Neurology, 2014; doi: 10.1212/WNL.0000000000000755)