INCREASED publicity about the link between vitamin D deficiency and a range of health problems has caused some Australians to scale back their sun protection, putting them at higher risk of skin cancer, an alarming new study has found.
The survey of 2100 people by the Queensland Cancer Council found about one-third of people aged 20 to 75 years believed fair-skinned adults and children needed at least 30 minutes a day in the summer sun to maintain adequate vitamin D levels.
But a group of skin, bone and cancer experts agree most Australians need only a few minutes of sunlight on their face, arms and hands in the sun to get enough vitamin D – and any more in summer puts them at increased risk of skin cancer.
It comes as a review by the International Agency for Research on Cancer finds there is no evidence that vitamin D deficiency raises the risk of prostate or breast cancer despite many epidemiological and preclinical studies around the world suggesting a link. However, there is a link for colorectal cancer.
"Anecdotally, a lot of the news on vitamin D has been used as a bit of an excuse by people who like going out into the sun to get more sun," Australasian College of Dermatologists honorary secretary Stephen Shumack said.
The survey, presented at the annual meeting of the Clinical Oncological Society of Australia, found more than 20 per cent of respondents had reduced their own sun protection behaviours and 14 per cent had lessened the slip, slop, slap regime for their children in response to reports about vitamin D deficiency.
But Dr Shumack, a consultant at Royal North Shore Hospital, said the message about vitamin D deficiency hasn’t been reaching the people who would benefit from getting additional sun exposure – particularly dark-skinned people, veiled women, babies and infants of vitamin D deficient mothers and nursing-home patients.
Australia has the highest incidence of skin cancer in the world. Sun exposure is the cause of about 99 per of non-melanoma skin cancers and 95 per cent of melanomas here.
Low levels of vitamin D, which is mainly synthesised from UV light, has also been linked to depression, osteoporosis and overall risk of death. #But the IARC review said an individual’s deficiency could simply be a consequence, or marker, of poor health, rather than the cause, and supplementation is then unlikely to prevent disease or improve health.
The safest way to maintain adequate vitamin D levels is by eating fortified foods such as milk and oily fish or taking a supplement rather than getting more sun exposure, the Australian and New Zealand Bone and Mineral Society, Osteoporosis Australia, the College of Dermatologists and the Cancer Council Australia, said in a joint statement.