New research shows almost 1 in 3 Victorians think they need the same amount of sun exposure in winter as in summer to maintain their vitamin D levels, despite ultraviolet (UV) radiation levels being so much lower in winter in Victoria.
The same proportion of respondents incorrectly think that fair-skinned people could maintain their vitamin D in winter with less than 15 minutes exposure per day or don't know how much sun exposure would be required.
Craig Sinclair, Director of the Cancer Prevention Centre at Cancer Council Victoria, said: "There is clearly a lot of confusion amongst Victorians around how much sun is enough for vitamin D during the winter months."
"Vitamin D is essential for bone and muscle development and the prevention of osteoporosis. The sun's UV radiation is the major cause of skin cancer as well as being the best natural source of vitamin D. As Victoria heads into the winter months, it is important to take a balanced UV approach to help with vitamin D levels."
From May until August in Victoria, the UV is generally below three, meaning sun protection is not required unless near highly reflective surfaces such as snow or outdoors for extended periods.
During this time of year, SunSmart recommends that people with fair to olive skin get two to three hours of midday winter sun exposure to the face, hands and arms (or equivalent area of skin) spread over the week to help with vitamin D levels. Daily exercise will further assist the body's production of vitamin D.
People with naturally darker skin may require up to three to six times more sun exposure to help with their vitamin D levels. During the cold and wet winter months in Victoria, it may simply not be practical or possible for some people to get this many hours of sun exposure each week.
"Population groups at risk of low vitamin D, including people with naturally very dark skin and those with little or no sun exposure, should discuss any concerns with their GP. Levels can be checked via a simple blood test and treated with supplements where required," said Mr. Sinclair.
The free SunSmart smartphone app features a vitamin D tracker that allows users to find out if they are getting enough sun to help with vitamin D levels and alerts the user to their daily sun protection needs.
- 47% of Victorians don't know why vitamin D is important for their health.
- Less than one quarter of Victorians knew that vitamin D is important for bone health.
- 8% of survey participants reported wearing sunscreen on a daily basis during winter. Yet, SunSmart advises that sun protection is usually not required during the winter months in Victoria unless near highly reflective surfaces such as snow or outdoors for extended periods.
- Most people (65%) correctly recognised that in summer, extra hours spent out in the sun wouldn't lead to a further increase in vitamin D levels. The body can only absorb a certain amount of vitamin D at a time, so prolonged sun exposure does not result in increased vitamin D levels, but does increase the risk of skin cancer.
About the research
Questions about vitamin D and sun exposure were included in a telephone survey of a representative sample of 1,490 adults residing in private households in Victoria aged 18 years and over that was conducted during July 2010 by a market research company on behalf of Cancer Council Victoria.