Cancer Council of Australia recommends 30 minutes of daily sunshine
Cancer Council
NBN news has a short podcast (audio only)
Which is also available at the bottom of this page
Apparently NBN and this section of the Cancer Council is in the Southern portion of Australia - where the UVB is not so intense
See also VitaminDWiki
Vitamin D research leads to surprising health tip – Australians need more time in the sun – May 2014
Vitamin D testing AND levels are increasing in Australia (NSW) – May 2014
Diabetes, hyperglycemia, depression, poor balance, etc associated with less than 20 ng of vitamin D in seniors – Feb 2014 Australia research
RCT confirms that Australians need at least 2000 IU vitamin D – Dec 2012