New research is aiming to put an end to confusion over whether people should avoid using sunscreen in case it prevents vitamin D production.
This comes as Cancer Council Queensland warns prolonged sun exposure does not result in an increase in vitamin D levels, but instead increases the risk of cancer.
QIMR Berghofer's Sun-D trial is investigating the effect of applying SPF 50+ on vitamin D, a hormone which is essential for bone health and is mainly generated in the skin through sun exposure.
The lead researcher Rachel Neale said many people were confused about how sunscreen would affect their vitamin D levels, causing them to either avoid sunscreen or spend too much time outdoors.
Professor Neale said the trial still needed another 500 participants from Australia's eastern states to sign up.
"We know that the sun has both benefits and harm, it causes skin cancer and other skin conditions, and Australia is the skin capital of the world," she said.
"So it is really important we protect our skin from the sun and sunscreen is one of the main ways in which we do that.
Professor Neale said in the southern states, the UV index was forecast to reach above three for a significant part of the year, except for a couple of months when that was not the case,
The trial aims to investigate what impact that may have on vitamin D levels.
Getting sunlight a balancing act
The Australian Health Survey in 2011-2012 found that 23 per cent of Australian adults had lower vitamin D levels, ranging from six per cent in Queensland to 19 per cent in New South Wales during summer.
In winter, the prevalence of vitamin D deficiency is higher in Victoria and the Australia Capital Territory at 49 per cent, compared with 16 per cent and 13 per cent, respectively, in summer.
Australia has the highest age-standardised rate for melanoma in the world, with Queensland having the highest rate in Australia.
One Australian is diagnosed with melanoma every 30 minutes, and one Australian dies from melanoma every six hours.
The QIMR Berghofer researchers are looking for participants from Queensland, Victoria, Tasmania and New South Wales for the one-year Sun-D trial.
There is a particular need for males from Queensland to sign up, where most participants who have registered have been female so far, and participants from Victoria and Tasmania, where there is the highest prevalence of vitamin D deficiency.
Trial participants will be split into two groups, with one group given free sunscreen to apply every day, while the other group is asked to continue with their normal sun protection habits.
During the trial, participants will complete monthly surveys and provide three blood samples to measure vitamin D levels.
The main source of vitamin D for most Australians is exposure to ultraviolet light from the sun — with only limited exposure needed to produce enough vitamin D.
The amount of sun exposure needed to make vitamin D depends on a range of factors such as the UV level, skin type and lifestyle, according to Cancer Council Queensland.
Cancer Council Queensland recommends against Australians exposing themselves to potentially harmful UV in order to get more vitamin D.
They say just a few minutes of exposure to UV index levels of three or above is enough.
"Most Australians get enough vitamin D with just a few minutes of sun exposure while completing everyday tasks — like walking to the car or shops," Cancer Council Queensland said in a statement.
For more information about the trial or to register interest, call 1300 735 920.
Anyone with any concerns about their health, skin cancer or vitamin D, should seek medical advice from their GP.
