We are just passing the Autumn Equinox, the point in the year when the hours of daylight and darkness are the same. From hereon in, those of us who live in the Northern Hemisphere will be seeing less of the sun as our hours of daylight decrease. How does this affect our health and well being?
Most of us will have experienced the psychological lift that sunshine gives us – in general we tend to feel better when the sun is shining – but is there more to it than this?
Does the reduction in our exposure to sunlight have implications for our wider health and wellbeing?
The role of Vitamin D
Vitamin D is essential for good overall health and strong bones. It has been shown to keep our immune systems healthy, as well as supporting muscle function, cardiovascular function, respiratory system, brain development and having anti-cancer properties.
Our bodies make their own Vitamin D from sunlight.
There are very few foods containing Vitamin D – with the exception of fatty fish and beef liver – so the only way of ensuring that we get enough of this essential vitamin is either by making sure we are exposed to sunlight regularly (specifically the ultraviolet B rays in sunlight) or by taking a supplement.
Vitamin D for bone health
Doctors initially made the link between Vitamin D and the prevention of rickets (a bone condition) in children many years ago. Subsequent studies have found that Vitamin D is effective in treating several serious long-term health problems.
The vitamin reduces inflammation in the body and studies have been made to determine whether it has any impact on recovery post-surgery.
A report published in 2014  found that higher Vitamin D levels were linked to decreased chances of morbidity and mortality in patients who had undergone non-cardiac surgery.
Vitamin D to protect against colds and flu too
Have you ever wondered why colds and flu spread more easily during the Winter?
According to a study published in February 2017  low levels of vitamin D are a contributory factor. It found a 12% reduction in people succumbing to acute respiratory infection after taking vitamin D supplements.
A lack of Vitamin D has been linked to cancer, asthma, type-II diabetes, high blood pressure, depression, Alzheimer’s and autoimmune disease like multiple sclerosis and Crohns.
Such compelling evidence about the benefits of vitamin D has prompted calls from some quarters for people living in Northern Europe to take Vitamin D supplements during the Winter, particularly those who tend to remain indoors. Some even suggests that our foods should be fortified with Vitamin D.
Without Vitamin D our bodies can’t perform at their best.
So, as we travel forwards into the darkening days, it’s worth giving some thought to how we can ensure sufficient levels of this essential vitamin in our bloodstream, whether that is walking outside in the frosty air or taking a regular supplement.
 Vitamin D supplementation to prevent acute respiratory infections: systematic review and meta- analysis of individual participant data’. Martineau et al. BMJ16 February 2017