Sensible sun exposure good for you

Image courtesy of NASA

For more than 40 years, dermatologists have been telling us that direct exposure to the sun causes skin damage and skin cancer.

What they overlook, however, is the many important biological processes that take place in your skin during 'sensible sun exposure'.

There are numerous chemicals that are produced in your skin, including beta-endorphins that improve your mood and nitric oxide that lowers your blood pressure.

A Vitamin D supplement does not provide these chemical benefits.

Vitamin D production occurs approximately between 10am to 3pm during spring, summer and autumn. In the early morning or late afternoon the UVB to UVA ratio is very low and your skin is blasted by UVA radiation. The UVA can alter your immune system and increase your risk of melanoma.

When you are exposed to sunlight, melanocytes in your skin produce a pigment called melanin, a natural sunscreen.

Sun exposure can cause cross-linking of your DNA, however there are enzymes present in your skin that separate and repair these cross-linked DNA.

Your skin is perfectly designed to heal the DNA damage produced by sensible sun exposure. Over exposure and incorrect sun exposure will cause skin damage.

The sun emits three types of UV radiation - UVA, UVB and UVC. Only UVA and UVB reach the surface of the earth.

A nominal percentage of UVA radiation is absorbed by the clouds and the ozone layer, in contrast to 95 per cent of UVB radiation. At the solar noon the UVB to UVA radiation ratio is high and approximately 85 per cent of the redness of your skin is caused by UVB radiation and only 15 per cent by UVA radiation.

To be truly sun sensible, download this app from dminder.ontometrics.com/. It calculates the best time, duration of exposure and units of vitamin D produced. It even sends you a reminder to reapply your sunscreen!

- Marie Proctor, through her company Health Renovator, is on a mission to help Kiwis take back their health.