As a species, humans have evolved over millions of years under the warmth and love of the sun and even in the west we have a history of using sun light therapy; the ancient Greeks called it – heliotherapy.
Vitamin D is one of the most important vitamins for long term health – it supports the immune system, brain and nervous system; it regulates insulin levels and supports lung function as well as helping our bones, skin, hair and eyes and digestion. Solar Ultra-Violet rays provide us with the best natural source of vitamin D which is absorbed through our skin by a process called dermal synthesis. This activates a secondary step in the liver and kidneys known as hydroxylation, enhancing our absorption of calcium, iron, magnesium, phosphate and zinc – essential for our bone health. Exposure to the sun also increases oxygen content in our blood, enhancing the body’s capacity to deliver that oxygen to the tissues.
It’s recommended that we try and get between 400 – 900 International Units (I U) of vitamin D a day, some of which can be obtained through food sources such as eggs, liver and fatty fish including salmon, trout, mackerel and tuna. However, sunlight (ultraviolet B rays) is by far the greatest, single source of vitamin D for most people.
By exposing a large expanse of skin (like the back) for no more than 15 minutes – clothing and SPF free – during the middle of day, our bodies can produce well in excess of the recommended I U.
Like everything in life, though it’s all about moderation – whilst it’s important to recognise the sun’s ability to heal all kinds of illnesses and bring about radiant health, it’s just as important to remember that over-exposure to the sun’s damaging UV rays can lead to far more than a severe case of sunburn.