How important is sun-protection to prevent skin cancers?

Apart from causing skin cancer, too much sun also damages the skin cells causing wrinkles, freckles, thinning of the skin and dilated blood vessels.

So it is extremely important to protect yourself from the sun, particularly during daylight-saving months in New Zealand, 11am to 5pm. Cover up with a broad-brimmed hat, clothing and sunscreen. Use a SPF30+, photo-stable broad-spectrum sunscreen 20 minutes before going out, and re-apply two-hourly if you can't avoid being in the sun for this long.

However, sunscreens are not perfect. Sun protection should always start with avoiding peak sun hours and dressing sensibly.Try to keep in the shade where possible. Remember that when you are near sand, snow or water or at high altitude, your risk of skin cancer is higher due to extra ultraviolet radiation.

 
Remember to make sure that babies and children that you are caring for are protected from the sun as well. Be cautious about using sunscreen for a baby under one year old. It's best to keep young babies out of the sun, and use shade, clothing and a hat as the main protection. A young child's skin may be irritated by sunscreen, so test it first on a small area of skin.

What about Vitamin D and the sun?

Vitamin D is essential for healthy bones. Low levels for long periods of time can lead to rickets in young people, and osteoporosis and fractures in older people. Some studies have indicated that low levels of vitamin D increase the risk of developing several types of cancer as well as some other medical conditions.

You get vitamin D from sunlight and from your diet, or from supplements. By enjoying the sun sensibly, it is possible for everyone to make enough vitamin D while not increasing their risk of skin cancer.

For the majority of the year most people should be able to achieve satisfactory vitamin D levels through incidental outdoor UV exposure before 11am and after 4pm. Darker-skinned people and elderly people will need a little more exposure than fair-skinned people. Everybody should try and avoid sun exposure at peak UV times, because of the skin cancer risk and the skin damaging effects.

However, during the winter, particularly in southern New Zealand, some people (particularly older people and darker-skinned people) may require dietary vitamin D supplementation. This should be discussed with your general practitioner. It is important not to exceed the prescribed dose as toxicity can occur.

The amount of time you need in the sun to make enough vitamin D varies from person to person. But the amount of sun needed to make enough vitamin D is always less than the high amounts that cause tanning or sunburn. Sunburn greatly increases the risk of skin cancer.

By taking steps to avoid burning, people can achieve a balance between reducing the risk of skin cancer and enjoying the beneficial effects of the sun. And most importantly, a regular skin cancer check by a doctor skilled in dermoscopy, is strongly recommended.