Participants with extremely low vitamin D levels were more than twice as likely to develop dementia and Alzheimer’s disease in a new study published in the journal Neurology.
Examining elderly Americans, the study found that those with extremely low vitamin D levels were 125 percent more likely to develop dementia of any kind and those who were moderately deficient had increased risk of 53 percent. For Alzheimer’s disease specifically, severe deficiency increase risk 122 percent and moderate deficiency increased risk 69 percent.
“We expected to find an association between low Vitamin D levels and the risk of dementia and Alzheimer’s disease, but the results were surprising – we actually found that the association was twice as strong as we anticipated,” lead researcher Dr. David Llewellyn of the University of Exeter Medical School said in a press release from the University.
The study also found that vitamin D levels above 20 ng/ml are most strongly associated with good brain health, and risk of dementia and Alzheimer’s disease is increased at levels below that threshold. The researchers had hypothesized that a vitamin D levels as low as 10 ng/ml would be adequate for good brain health.
“Shedding light on risk factors for dementia is one of the most important tasks facing today’s health researchers,” Alzheimer’s Society Director of Research and Development Doug Brown said in the press release from the University of Exeter. “While earlier studies have suggested that a lack of the sunshine vitamin is linked to an increased risk of Alzheimer’s disease, this study found that people with very low vitamin D levels were more than twice as likely to develop any kind of dementia.”