Adults with higher vitamin D levels had better mental ability, and doctors ponder the link between low vitamin D levels and autism, in three new studies.
Doctors in a brain study explained that with age, the body absorbs less vitamin D from the sun, and that the elderly living in areas with dark winters typically don’t get enough of the sunshine vitamin. Researchers measured vitamin D blood levels and mental (cognitive) ability in about 1,800 men and women, aged at least 65, and found that as the level of vitamin D declined, the chances of being cognitively impaired rose. About half of those who were cognitively impaired had the lowest levels of vitamin D, and were more than twice as likely to be impaired as were those with the highest vitamin D levels.
In another brain study, doctors said that animal studies have found vitamin D increased brain nerve signals and protected nerves, and wanted to test vitamin D and mental performance in older men. Researchers tested over 3,000 men, average age 60, and found that those with high vitamin D levels could copy objects and recall better, and process information faster than men with low levels. While the difference was modest, doctors noted, “If cognitive function could be improved by a simple intervention such as vitamin D supplementation, our results would have potentially important implications for population health.”
Scientists in an autism study suspect that part of the reason autism rates have increased 16 times over the last 30 years is because of lack of sunlight. Over a 14-year period, researchers compared rainfall in California, Oregon and Washington counties to the number of autism cases in school children there and found that autism rates were much higher for counties with more rain and snow. Researchers are hoping, in future studies, to understand how precipitation may trigger autism in genetically prone children.