As Victoria heads into the winter months, now is the time for people to make sure they get some sun to help with their vitamin D levels.
Ultraviolet (UV) radiation from the sun is the main cause of skin cancer but also a good natural source of vitamin D, which is important for general health.
SunSmart Manager Sue Heward said it's important to take a balanced approach to UV exposure and vitamin D.
"The key to achieving a balanced approach is to know what the UV level is each day," Ms Heward said. "When UV is low (below 3 on the UV Index), it is generally not damaging to the skin and eyes.
"Low UV occurs in Victoria between May and August each year, making it a great time to get some winter sun to help maintain vitamin D levels.
"Our recommendation for UV exposure from now until the end of August, for most people, is to expose their face, arms and hands (or equivalent area of skin) for two to three hours spread over the week. People with naturally very dark skin need three to six times this exposure."
Ms Heward said new research commissioned by SunSmart shows that Victorians are not getting enough sun exposure for vitamin D over the winter months.
"The Newspoll study showed that 69% of Victorian adults didn't meet the recommended sun exposure requirements in winter 2009," she said.
"There are some simple ways that people can increase their daily dose of sun. For example rolling up your sleeves on your daily walk or getting out for some fresh air in the middle of a clear day can make a difference to your vitamin D levels over winter."
Professor Peter Ebeling, Medical Director of Osteoporosis Australia and Head of Endocrinology, University of Melbourne at Western Hospital, said sun exposure may not be enough for some sections of the population and supplementation may be required.
"People with naturally very dark skin, babies and infants of vitamin D deficient mothers (especially breastfed babies), people who cover their skin for religious or cultural reasons, older Victorians and people who are housebound or in institutional care are at risk of being deficient in vitamin D," Professor Ebeling said.
"Vitamin D deficiency has been linked to an increased risk of bowel cancer, heart disease, infections and auto-immune diseases, such as diabetes and rheumatoid arthritis, although more research is needed for any conclusive evidence to be derived.
"If people have any concerns, they should consult their GP. Vitamin D levels can be checked through a blood test and inadequate levels can be treated with supplements. People should never try to boost their vitamin D levels at any time of the year through excessive UV exposure or through using solariums."
Ms Heward said the study also indicates that ongoing community education is required about when to use sun protection and when it's ok to get some sun for vitamin D.
"The general rule of thumb is that from September to April in Victoria the UV Index is at 3 and above and therefore sun protection is needed," she said. "During this time, most people get enough sun exposure for vitamin D by going about their normal day-to-day activities.
"But from May through to August, when UV levels are below 3, sun protection is only needed if people are in Alpine areas, spending extended periods of time outdoors or near highly reflective surfaces such as snow.
"To find out UV levels, get into the habit of checking the SunSmart UV Alert everyday at www.sunsmart.com.au, where you can also get information on vitamin D, skin cancer and sun exposure recommendations."