The best things in life are free but everything in moderation. Vitamin D or, ‘The Sunshine Vitamin’ is a beautiful example. Our bodies have evolved over millions of years to draw what they need from nature either through dietary consumption or environmental exposure but is there too much of a good thing?
Nature Will Find a Way
Our bodies are incredibly complex but fortunately for us they happily perform most tasks without our direction. Our bodies create Vitamin D through exposure to the sun’s rays or through extraction from limited food sources such as fatty fish (salmon, tuna, mackerel, etc) and to a lesser extent animal liver, cheese, and egg yolks. Our bodies however do not directly use Vitamin D. They then convert it into a hormone used for calcium generation and bone regeneration. Deficiencies in Vitamin D can therefore lead to osteoporosis and rickets.
Sunshine Make you Happy
While our bodies to a large extent operate on autopilot, it is our minds that control our behaviour and actions. So how does our body maintain homeostasis (or inner balance) if it is not in the always directing the show? Feedback loops. Our bodies are very good at giving us signals when we are deficient in something. They create certain feelings and emotions directing us to act on these, changing current behaviour, then allowing the body to return to balance. This holds true for the feeling of hunger and eating, stress and life changes, and for sadness and Vitamin D.
Due to the relationship of vitamin D to bone health and the invisible skeletal system, symptoms of deficiency are not always overly clear. Vitamin D has however been linked to muscle aches, depression, energy levels, and poor immune systems. When correctly diagnosed, the source of therapy, the sun and supplements, are fortunately readily available in Australia. The removal of the deficiency can therefore lead to the removal of the negative feedback loops, resulting in the return of normal moods. If only every disorder could be cured with a beautiful dose of the outdoors.
The efficiency of Evolution
Although the world may feel wasteful at times, nature itself demands efficiency. Not only have our bodies learnt to draw what they need from nature they have also learn to do it in an incredibly efficient way. There was no time for tanning on the Savannah’s when tigers were on the hunt. We evolved to get our required dose in a very short period of time. In most cases, people in Australia can maintain normal Vitamin D levels through normal periodic exposure to the sun. This includes walking to and from meetings and appointments, sitting in naturally lit environments, and normal outdoor exercise behaviours. Rarely do Australians require deliberate sun exposure for vitamin D purposes but may need to increase outdoor activities slightly during the winter months.
For the sun and our skin to work their magic they do require some exposure. Those who tend to cover their skin more, are immobile or unable to move outdoors, with naturally higher and protective skin colour, and those living closer to the poles where the sunlight is variable throughout the year with a lesser intensity tend to suffer from Vitamin D deficiency more readily.
Due the reasons above, within Australia, cases tend to be more prevalent in the southern states during winter when the UV index is low and the need to cover the skin for warmth is high. For our personal solar panels to operate they require some exposure and during the winter months when the U.V factor is lower the amount of time required increases considerable. During the summer months studies suggest exposures of between 5-8 minutes, 4-6 times a week in the mainland states. In winter however the northern states vary little in requiring 9-19 minutes while the southern states increase dramatically to 30-40 minutes.
Recommended Exposure Times (mins)
Source: Working group of the Australian and New Zealand Bone and Mineral Society, Endocrine Society of Australia and Osteoporosis Australia. Vitamin D and adult bone health in Australia and New Zealand: a position statement. Med J Aust 2005;18:281-5.
Too much of a Good Thing
The good news is Vitamin D is free and efficiently produced. The bad news is, UV rays, a key ingredient in the process, are harmful in excessive doses. As mentioned Australians living a healthy and varied lifestyle rarely suffer from Vitamin D deficiency . It is important to understand that rarely do we require deliberate exposure to the sun for Vitamin D productions. As our bodies begin to produce Vitamin D once the UV index is above 3 we can safely obtain adequate levels without exposure to extreme and high UV index levels.
Should you have concerns regarding your families Vitamin D levels it is important to consult your local doctor. They can then prescribe the safest means of reestablishing normal levels. Stay happy. Stay strong.