VITAMIND: THE FACTS

AS THE MERCURY RISES, SO DOES THE DEBATE ABOUT WHETHER WE GET ENOUGH VITAMIN D. SHERINE YOUSSEF REPORTS

F eel that? It’s the heat generated by summer’s hot topic: Are we getting enough vitamin D, or have we slip, slop, slapped our way to a national epidemic of D-deficiency?

Professor Michael Kimlin, a specialist in the study of vitamin D and skin cancer at the AusSun Research Lab at the Queensland University of Technology, sorts the facts from the fiction. A WHOLE GENERATION OF

AUSTRALIANS SEEM TO

BE VITAMIN D DEFICIENT

– WHY IS IT AN ISSUE NOW? “We’re unsure. Perhaps it’s always been there, or we’re measuring it more – people are having blood tests that check vitamin D levels. If we cast our minds back 50 or 60 years, our lifestyle has changed – we’re spending more time indoors, in front of the TV and computer, so the patterns of exposure to sunlight have changed.”

WHO’S MOST AT RISK OF

A DEFICIENCY? “Those in southern areas of Australia in winter; those with dark skin; those who wear lots of clothing for cultural or religious reasons. That said, it can happen to anyone. If someone spends a lot of time indoors, or has been sick, they should [consider] being tested.”

IS TOO MUCH SUNSCREEN

PART OF THE CAUSE? “Sun protection doesn’t stop people making vitamin D. Generally, those using sunscreen have high vitamin D levels because they’re the ones spending time outdoors. Because melanoma and other skin cancers are prevalent here, and the sun does have a hugely adverse health effect, we’d be wise to continue our sun protection messaging.”

IS THERE SUCH A THING

AS SAFE SUN EXPOSURE? “In the Australian sunshine, [safe exposure] is minutes, not hours, especially in summer. The evidence so far is that incidental exposure – such as when you’re at work and go out for a coffee – tends to be enough. For places such as Melbourne and Hobart in winter, [safe exposure] is hours because their sunlight is much weaker, but otherwise, minutes in the middle of the day are enough.” ARE SUPPLEMENTS AS

EFFECTIVE AS SUNLIGHT? “They are. Your body can’t tell the difference between vitamin D from a tablet and from the sun, and those who take supplements tend to have higher levels than those who don’t. So they’re a good thing, particularly for those in colder climates in the south. Even in sunny Brisbane, those who take supplements have higher vitamin D levels, on average, than those who don’t. But as with any over-the-counter supplement, it’s a conversation to have with your GP.”

WHAT’S A SUFFICIENT

LEVEL OF VITAMIN D? “Research from the US gives a figure of 50 nanomoles per litre. That’s a relatively conservative amount, and most people in Australia do reach it, but there are certain times of year, and certain people, who may be below it.”

DOES THE SITE OF SKIN

EXPOSURE MAKE ANY

DIFFERENCE? “There’s no evidence to suggest exposing your chest, stomach or back is better than your face or hands.

Just getting out in the sun and rolling up your sleeves or trouser legs would be sufficient. The body is remarkably efficient at making vitamin D.”

CAN APPS THAT “TRACK”

VITAMIN D LEVELS HELP? “The Cancer Council Australia’s Sun Smart app (sunsmart.com. au) is a good starting point. It gives recommended times in the sun, but also balances that out with times to protect your skin.”

WHERE’S YOUR RESEARCH

TAKING YOU NEXT? “We’re trying to focus on exactly how we can maintain sufficient vitamin D levels in Australia. Is it [down to] where you live – in the tropics or in Melbourne, Sydney or Brisbane? Is it your skin colour? The clothes you wear or the food you eat? From that information, we hope to be able to help refine and better develop our messages for public health officials around vitamin D.”