Growing up in Australia where there is an abundance of sunshine and an outdoor lifestyle, we have always been told to “slip, slop, slap” in an attempt to prevent skin cancer and premature ageing. However, recent studies have estimated that up to 60-70 percent of Australians have insufficient levels of Vitamin D and are unaware of their deficient state. While conventional medicine and the media promote sun avoidance, doing so could actually put your health in danger and be causing a deficiency of this essential vitamin.
While it is well known that Vitamin D is essential for bone health, it has now also become evident that Vitamin D plays a pivotal role in cell metabolism, cardiac health, immune function, neurological support and the regulation of systemic inflammation, a process central to the onset of chronic diseases.
The breadth and the strength of the scientific evidence supporting Vitamin D’s protective role is remarkable. In terms of health disorders including heart disease, stroke, infectious and respiratory diseases, diabetes, depression, muscle weakness, asthma, fibromyalgia, arthritis, osteoporosis, psoriasis, multiple sclerosis, hypertension, hyperglycaemia, autoimmune dysfunctions, peripheral nerve disorders, dementia, and common cancers, the protective role of Vitamin D is now definitively established.
According to one large-scale study, optimal Vitamin D levels can slash your risk of cancer by as much as 60 percent. Keeping your levels optimized can help prevent at least 16 different types of cancer, including pancreatic, lung, ovarian, prostate, and skin cancers. This remarkable finding suggests that Vitamin D could be one of the most effective ways of preventing and even possibly treating cancer.
While scientists refer to Vitamin D as a vitamin, it is actually a steroid hormone obtained from sun exposure, food sources, and supplementation.
If you are deficient in Vitamin D then healthy sun exposure is a beneficial way to optimise serum levels. While sunlight is the preferred source of Vitamin D it is often difficult to achieve adequate exposure to sunlight to reach the optimum blood serum level of (50-70ng/ml). The best way to know if you are deficient in Vitamin D is through a simple blood test performed by your GP.
Contrary to previous recommendations, recent evidence suggests that exposing your skin to the sun as close as possible to the solar noon (1pm daylight saving time) and between 10am and 2pm with 40% of your body exposed for a period of 10-20 minutes will allow for optimal absorption of Vitamin D with less risk of causing skin damage and possibly skin cancer. The reason for this is that the sun omits two types of wavelengths at different periods throughout the day. Your body requires UVB rays for Vitamin D production and the UVB rays are at their highest at the solar noon and offer protection from UVA rays which have longer wavelengths and increase the risk of skin cancer and photo aging.
Alternatively, if safe sun exposure is unachievable then supplementing Vitamin D is a very beneficial way to increase your serum levels and is found to have the same health benefits. (Recommended dosage for average adult is 5000 IU per day).
In conclusion, it is always important to be aware that the above recommendations may not be correct for you personally as they are guidelines only. The best way to know if you have achieved adequate serum levels through either sun exposure or supplementation of Vitamin D is to have your GP retest you blood serum levels.
Dr Hilary Cornish is an Osteopath and Pilates instructor at Melbourne Osteopathy Sports Injury Centre.
References and further reading:
1. Dr. Joseph Mercola http://www.mercola.com/article/vitamin-d-resources.htm
2. Grant WB, Holick MF. Benefits and requirements of vitamin D for optimal health: a review. Altern Med Rev. 2005 Jun:10(2): 94-111.
3. MacWilliam L. NutriSearch Comparative guide to nutritional supplements (5th Ed). Northern Dimensions Publishing, USA.