If an award were given out for the most popular and talked-about supplement of the year, it's fair to say that vitamin D might win the contest. Dozens of research studies reveal that vitamin D deficiency is at the root of many chronic diseases and new studies keep springing up week after week, amounting to an Everest-size pile.

Another topic that has been frequenting the medical journals is brain health; cognitive decline, dementia, and Alzheimer's are becoming more prevalent in our aging society and this issue is suggesting the need to examine ways to prevent cognitive decline or halt its progress. There is significant concern about controlling the medical costs associated with the most severe condition, Alzheimer's, which can be emotionally and financially devastating to the patient and his or her family.

Not surprisingly, the topic of vitamin D and cognitive function have intersected in a recent research study, supporting the theory that vitamin D reduces inflammation and offers neuroprotection. The results of this study may inspire physicians to add vitamin D to their "cognitive support" protocol.

Published in the Archives of Internal Medicine, this Italian study spanned six years, and followed 865 adults aged 65 and older. Every three years, participants' vitamin D levels were measured and cognitive function was assessed with a test called the "Mini-Mental State Examination."

The resulting data showed that there was a 60% increased risk of substantial cognitive decline in those who were severely serum 25(OH)D deficient (levels <25 nmol/L) in comparison to those with sufficient levels of 25(OH)D ( 75 nmol/L).

The authors' conclusion was "Low levels of vitamin D were associated with substantial cognitive decline in the elderly population studied over a six-year period, which raises important new possibilities for treatment and prevention."

The Vitamin D Council website (www.vitamindcouncil.org) lists more than 60 studies that explore the relationship between vitamin D levels and cognitive function to support this particular study. And don't forget that Vitamin D has co-factors that enhance absorption, including magnesium, zinc, K2, and boron.