The Sun Exposure and Vitamin D Supplementation Study team Professor Robyn Lucas, Mica Hartley, Laura King, Dr Sam Hoare and Associate Professor Fiona Lithander.

The Sun Exposure and Vitamin D Supplementation Study team Professor Robyn Lucas, Mica Hartley, Laura King, Dr Sam Hoare and Associate Professor Fiona Lithander.

Sunny days

If you think vitamin tablets are just as good as real thing, think again. TEGAN DOLSTRA reports.

In the last decade, Medicare spending on vitamin D testing increased from $2 million to $145 million a year. Australians are concerned about vitamin D. And so they should be. Data released by the Bureau of Statistics in 2012 showed that almost 4 million Australians aren't getting enough.

Vitamin D is a hormone, produced when sunlight makes contact with your skin. So what are we in The Lucky Country, known for its abundant sunshine, so worried about?

"We've known for a long time that vitamin D is really important for bones," says Professor Robyn Lucas from the National Centre for Epidemiology and Population Health at ANU.

"Most people have seen the old photos of those poor kids with rickets, where their bones bend out or they have knock knees.

"On top of that, vitamin D has recently been linked to just about every disease you could think of - autism, diabetes, multiple sclerosis, cancers. You name it, vitamin D will be linked to it."

Although oily fish like herrings and sardines offer small doses of vitamin D, Australians get more than 90 per cent of their daily requirement from sun exposure. The trouble is, too many people are spending too much time in the office.

"You only need to spend five minutes in the sun each day in summer to make enough vitamin D," says Lucas.

"But these days, we come to work early in the morning and we go home when it's getting dark. Computers have driven our kids inside. It's hardly surprising that people will become vitamin D deficient."

At this point, alarm bells might be ringing - sun exposure leads to skin cancer, right? Many people might opt to play it safe and take vitamin D tablets instead.

But, Lucas warns, they might be missing out on a whole lot of other perks.

"Five minutes in the midday sun is enough to make your daily vitamin D requirement without getting a dose of UV that kills your cells," she says.

"But there are other benefits of sun exposure that we're only just starting to discover."