Two studies that were conducted at the French National Institute of Health and Medical Research (Inserm), Bordeaux Population Health (Bordeaux University) show that vitamin D deficiency can contribute to increasing the risk of developing Alzheimer’s disease, especially if the person also doesn’t have a storage of “good fats” and antioxidant carotenoids.
The studies led by Inserm researchers Catherine Feart and Cecilia Samieri involved around 10,000 people aged 65 and above who were in good health or at least not suffering from Alzheimer’s disease. The research began in 2000.
The study participants were seen by psychologists for 17 years wherein they underwent a battery of tests to determine if they succumbed to a form of dementia, including Alzheimer’s. Feart and Samieri used biobank samples of the study participants to look for particular nutrient concentrations: fatty acids, carotenoids, and vitamins A, D, and E.
Of the 10,000 study participants who were lacking in vitamin D levels, 177 developed a form of dementia, including 124 cases of Alzheimer’s, during 12 years of follow-up. The participants with vitamin D deficiency (25 percent) or insufficiency (60 percent) had twice as much risk of developing dementia and nearly thrice as much risk of acquiring Alzheimer’s disease, as compared with those who had sufficient vitamin D status.
For the second study, the researchers studied the blood concentrations of 22 lipid-soluble nutrients among 666 participants without dementia. The study concluded that people with the lowest combined blood carotenoid, polyunsaturated fatty acid (good fat), and vitamin D concentrations had four times as much risk of developing dementia including Alzheimer’s disease.
“This kind of deficiency appears to be linked to a high risk of developing Alzheimer’s disease, especially when there is also a negative ‘good fat’ profile and antioxidant carotenoid intake is poor. The additional risk from this multiple nutrient deficiency appears to be significantly higher than the genetic risk,” the researchers say.