Research links sun, shade and Vitamin D

A USQ Academic has received a Queensland Cancer Fund (QCF) research grant to continue his studies into the effect of UV rays and shade on the creation of Vitamin D in humans.

The QCF has awarded USQ Researcher, Dr David Turnbull, with $78,000 to continue his research.

Dr Turnbull said through his research so far, he had discovered that humans in high exposure climates, such as Queensland, do not need direct sunlight to receive their Vitamin D intake.

'There is a significant proportion of solar UV present in shade due to the scattering in the earth's atmosphere and Vitamin D is actually absorbed from the UVB rays, which are found in shade,' Dr Turnbull said.

'It is estimated that 90-95 percent of our Vitamin D requirement comes from exposure to UV radiation. Previously the scientific community has believed humans needed a certain amount of direct sunlight every week to avoid developing a Vitamin D deficiency.'

A Vitamin D deficiency can lead to health problems such as osteoporosis, rickets, and various cancers. Vitamin D has also been linked to diabetes, bacterial infections, schizophrenia, multiple sclerosis and inflammatory bowel disease.

Dr Turnbull's research is quite significant, especially in Queensland where one out of three people develop skin cancer.

'Although over exposure to these UVB wavelengths are known to cause skin damage, Vitamin D synthesis generally occurs at sub-damaging irradiances,' he said.

'Both UVA and UVB rays are present in direct sunlight, however the relative proportions of UVA and UVB in the shade are significantly different to those in full sun.

'Therefore, those spending time in the shade may be able to synthesise their Vitamin D without experiencing the high levels of damaging UVA observed in full sun,' Dr Turnbull said.

He said it was also important that people are aware that Vitamin D can only be made by the body when sunlight falls on skin unprotected by sunscreen.

'The importance of this research is that it would provide a basis for public health campaigns, in high exposure climates, aimed at reducing the incidence of Vitamin D deficiency and its attendant disorders, as well as reducing over exposure to harmful solar UV radiation,' he said.

Dr Turnbull presented his findings at the Queensland Health and Medical Research Conference and Australian Institute of Physics National Congress in Brisbane recently.

Final outcomes from the research are expected at the end of 2009.

Media Contact: Fiona Taylor, USQ Media, +61 7 3470 4117 or +61 423 808 462