New research on vitamin D has found that low levels of the vitamin are associated with an increased risk of cognitive decline in Chinese seniors.

Vitamin D is already known to have many health benefits, including improved bone health, lower blood pressure, reduced risk of heart attack, stroke, and heart failure, lower risk of multiple sclerosis, and better chances of surviving cancer.

It has also been found to have a significant effect on cognitive health, with previous studies in Europe and North America showing that a low level of vitamin D is linked with an increased risk of cognitive decline. This new study, conducted by Duke-NUS Medical School (Duke-NUS) and Duke University, is now the first large-scale prospective study in Asia to look at an association between vitamin D levels and the risk of cognitive decline and impairment in the Chinese elderly.

To look at the possible association, the team of researchers recruited 1,202 participants 60 years of age or older from the Chinese Longitudinal Health Longevity Survey, carried out by the university.

The baseline vitamin D levels of participants were measured at the start of the study and participants' cognitive abilities were assessed over a two-year period.

The results showed that across both men and women, and regardless of how advanced the age, those with lower vitamin D levels at the start of the study were around twice as likely to exhibit significant cognitive decline over time than those with higher levels of the vitamin.

In addition, those with low vitamin D levels at baseline also showed a 2-3 times increased risk of future cognitive impairment.

The results provide further evidence that vitamin D could have a protective effect against cognitive decline and suggest further research in the area in the hope of identifying effective interventions to help tackle the increasing rates of cognitive decline in aging populations.

Professor David Matchar, first author of the study, also added that, "Although this study was conducted on subjects from China, the results are applicable to regions in Asia where a large proportion of the elderly are ethnically Chinese, like Singapore."

For those looking to increase their levels of vitamin D, the main source of the vitamin is from exposure to sunlight, however individuals can also increase their levels by consuming foods rich in the vitamin such as oily fish, including sardines and mackerel, beef or calf liver, eggs and cod liver oil.

The findings can be found in The Journals of Gerontology Series A: Biological Sciences and Medical Sciences.