Recent research out of Yale University has uncovered an interesting new aspect to the function and benefit of vitamin D in the human body. Preventing colds and influenza.
Influenza is a very common virus that is particularly prevalent in colder seasons and climates. This fact has led many to speculate as to why with the bulk of theories suggesting the lower temperatures allow the pathogens to survive longer and be transmitted more easily. Alternatively, it has been put forward that behavioural changes related to the season make people more likely to contract the virus.
An unusual anomaly stood out to the Yale researchers, which led them to investigate and come to a new conclusion. Indoor crowding is a recognized cause of influenza epidemics and increase in virus transmission. In winter this effect is much more pronounced than in summer, despite the presence of the virus and the same behaviour exhibited by people in workplaces and public transport, etc.
This inspired the researchers to examine other factors dependent on the season, including individuals’ levels of vitamin D.
As discussed previously, vitamin D is an important substance for maintaining good health and psychological well-being. While it’s full role in the human body is not completely understood, it is well documented that exposure of skin to sunlight enables the body to synthesise the vitamin and is the most effective natural source.
A theory was postulated that people living in regions that experience higher UV exposure would experience a lower incidence of cold and flu than those from regions with less UV exposure.
The study found that maintaining a level of vitamin D in the blood equal to or greater than 38 nanograms per mililitre could reduce the likelihood of contracting influenza by more than half.
The establishment of a direct link between vitamin D and a recognized illness enables physicians to fortify those who are most at risk of contracting influenza.
Those with traits that imply they have low levels of vitamin D, such as the dark skinned, obese or pregnant.
The broader implications for these findings are significant when considering the number of working days and hours lost to the common cold or flu. Reducing influenza incidence could have a profound impact indeed when considering that in the US alone it is responsible for losses in productivity worth over $10 billion.
Reference:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2885414/
Image reference:
http://www.flickr.com/photos/36128932@N03/3338845735/
