We need our place in the sun, too

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While it is important to protect the skin from the sun and the melanomas which can result from over exposure, it is also critical that people understand the many benefits of vitamin D - the production of which is stimulated by ultraviolet radiation, writes Janet Carrington.

Exposure to the sun is known to be responsible for the initiation of melanoma and other skin cancers.

In New Zealand we have the highest rates of death from melanoma in the world because our temperate climate means being out in the sun is taken for granted.

To reduce the incidence of melanoma and other cancers a trendy mantra - slip, slop, slap and wrap - was introduced and SunSmart advice provided in schools.

Most could see the logic, were captivated and assiduously followed the recommendations.

But have the consequences been fully understood? Is the advice taken too diligently? Recently I saw a television advertisement for a product containing SPF 80+! Dunedin and Invercargill have 75% of the sunshine per year that Christchurch, Auckland and Wellington do.

We have a cooler climate, so there aren't as many days when it's comfortable to be out in the sun and besides there's shopping, DVDs and computers keeping us indoors and to make life more comfortable we're even planning to build a covered stadium!On the other hand, the sun's ultraviolet radiation promotes the synthesis of vitamin D in the skin so not getting enough time in the sun leads to low levels of vitamin D.

The sun is our main source of vitamin D because the few foods that contain vitamin D, like oily fish and eggs, provide only a small amount.

So it is important for everyone to have regular safe sun exposure.

Because vitamin D is fat soluble, what is made in the summer can be stored for the winter months, when it is colder and being out in the sun is less inviting, but that means it's imperative to be exposed to the sun when appropriate during the summer.

Vitamin D has an important role in maintaining blood calcium and phosphate levels by enhancing absorption of these minerals to promote bone formation and the production of strong healthy bones.

Low levels of vitamin D have been linked to reduced immunity, cancers, autoimmune disorders, diabetes, cardiovascular disease, schizophrenia, depression and autism.

Even now there are pleas for more funds to publicise the danger of being out in the sun.

But let's be rational - while keeping the danger of overexposure to the sun in mind, in the South it is essential to spend some time out in the sun.

Enjoy.

• Dr Janet Carrington is a retired senior lecturer of the University of Otago's biochemistry department.