Chase the sun for vitamin D

A survey by the Victorian Cancer Council has found a widespread lack of public understanding about how much sunlight is required in winter to maintain healthy vitamin D levels.

Above: Gardening is a one way of getting out in the sun (image: Bupa Care Services).

By Yasmin Noone and Stephen Easton

A survey of nearly 1,500 Victorians has shown that many do not know how much sunlight is requried in the southern winter to maintain healthy levels of vitamin D, which is produced in the body through exposure to ultra-violet (UV) radiation.

In general, UV levels are much lower in winter than in summer, so more exposure to sunlight is needed to keep up levels of the nutrient, which is essential for general health and more specifically, healthy bones.

Cancer Council Victoria, which normally tells people about the dangers of UV, said that one third of those surveyed thought the amount of sunlight required for healthy Vitamin D levels was the same in winter as in summer. 

The amount of sunlight required varies throughout the year, and across the country – in summer, only a few minutes on most days is recommended, no matter where you live in Australia and up north, the same warning applies all year round.

But much more sunlight is required in the southern winter – between two and three hours per week of midday sun to make enough vitamin D, as a rough guide. Sun protection is not requried when the UV rating is below three.

Click here for SunSmart’s brochure containing the recommendations for each part of Australia.

Daily exercise will further assist the body’s production of vitamin D, and people with darker skin may need between three and six times as much exposure as people with light skin.

Craig Sinclair, director of Cancer Council Victoria’s Cancer Prevention Centre, said the results revealed clear confusion among Victorians about the balance between too much sun exposure and not enough.

“The sun’s UV radiation is the major cause of skin cancer as well as being the best natural source of vitamin D,” Mr Sinclair said. “As Victoria heads into the winter months, it is important to take a balanced UV approach to help with vitamin D levels.”

According to Jen Makin, who manages SunSmart Victoria, older people are more likely to have a vitamin D deficiency, especailly if they spend a lot of time indoors.

“Older Australians, particularly those who are immobile, hospitalised or indoors for much of the day, are at increased risk of vitamin D deficiency due to low levels of sun exposure,” Ms Makin said. 

“The older adult population is especially vulnerable to vitamin D deficiency, due to a decreased capacity to synthesise vitamin D from sunlight.”

Ms Makin said that as well as general health, vitamin D helps prevent the bone diseases osteomalacia and osteoporosis.

“There have also been suggestions that vitamin D deficiency plays a role in fractures, muscle weakness and consequently, falls, however further research is required to confirm this link.” 

Although some foods, such as oily fish and eggs contain small amounts of vitamin D, and others like margarine and milk sometimes have it added, food usually provides only about 10 per cent of the body’s vitamin D needs, and it is difficult to get enough vitamin D from diet alone. 

“Vitamin D is important at all ages but given the difficulties faced by older people in getting enough sun for vitamin D, supplementation maybe required,” Ms Makin added. 

SunSmart also has an online vitamin D tracker and a free smartphone app, both of which allow users to find out if they are getting enough sun to maintain healthy vitamin D levels, and alert the user to their daily sun protection needs.

Tags: smartphone, sunlight, vitamin-d,

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