Vitamin D deficiency linked to increased dementia risk

Researchers have found the largest and most robust link between dementia and vitamin D deficiency in older adults, reported BBC News.

While this link is not a new discovery, the study showed a strong association. Scientists observed a group of about 1,650 adults age 65 and older for six years. More than 1,100 of the participants had good levels of vitamin D and had a 1 in 10 chance of developing dementia. Seventy participants were severely deficient and had about a 1 in 5 risk of dementia.

"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 study author Dr. David Llewellyn of the University of Exeter Medical School in the U.K. said.

Vitamin D can come from sunlight, supplements and certain foods like oily fish. Because older adults’ skin can be less efficient at converting sunlight into Vitamin D, they can become deficient and need to rely on other sources. However, experts say the study’s findings don’t mean all adults need to take supplements as a preventative measure.

"At the moment, we are still unclear how the two might be linked, and there is even a possibility another unknown factor could cause someone to have both dementia and low vitamin D levels,” Dr. Clare Watson of the Alzheimer’s Society in the UK, said. "If this were the case, using supplements or sun exposure to raise vitamin D levels might have no effect on the development of dementia or Alzheimer's disease."

According to the Alzheimer’s Association, dementia is not a specific disease, but a general term for a decline in mental ability severe enough to interfere with daily life.

Researchers noted that their findings were encouraging.

“…Even if a  small number of people could benefit, this would have enormous public health implications given the devastating and costly nature of dementia,” Llewellyn said.

Click for more from BBC News.