Skip to content

Looking at the Sunny Side of Bone Health

It is ironic that in a sunny country like Australia we often talk about the need for adequate vitamin D for bone health.

It is well-known that vitamin D supports the growth and maintenance of the skeleton and assists in regulating calcium levels in the blood.

For most Australians, the main source of vitamin D is from exposure to sunlight. Vitamin D is produced when skin is exposed to ultraviolet B (UVB) light from the sun, and the length of exposure required to produce vitamin D is relatively low.

So, the issue of vitamin D for the health of Australians is a balancing act which includes: avoiding skin damage from excessive exposure, the season, your skin type and the latitude where you live.

It is also common for Australians to have their lower vitamin D level at the end of winter so it’s a good time to discuss the issue.

It sounds complicated, but we are fortunate to have research and experts to provide easy guidance on this topic, and we’re aided by online UV indexes which link to location.

Seasonal Changes

In summer, most Australian adults will maintain adequate vitamin D levels during typical day-to-day outdoor activities.

When the UV index is above 3 (all states during summer and some states in winter months), you should use sun protection measures when outdoors for more than a few minutes.

In winter, longer exposure times are needed in southern states and preferably around midday. In autumn or winter, in states where the UV index is below 3 for most of the day, sun protection isn’t needed.

For checking UV index visit the Cancer Council’s website or

Testing Vitamin D

Vitamin D levels can be checked with a blood test and it is recommended that people have a minimum vitamin D level of 50 nmol/L at the end of winter, with levels commonly higher during summer.

Vitamin D testing is not required on a routine basis and should only be conducted in patients who are at risk. This may include:

  • the elderly, housebound or those in residential care
  • people with naturally dark skin (darker skin reduces the penetration of UV light)
  • people avoiding the sun for skin protection, due to medical advice for other medical reasons
  • people covering their body for cultural or religious reasons
  • people with medical conditions that impact the ability to absorb and/or process vitamin D
  • babies of vitamin D deficient mothers.


Low vitamin D levels can be in the range of mild, moderate or severe. If required, supplements can be used to correct low vitamin D levels and typically can take several months to initially increase levels.

Most vitamin D supplements are ‘D3’ with the amount shown in International Units (IU).

There are now a wide variety of vitamin D supplements available in Australia including tablets, capsules, liquid drops, and most recently weekly tablets.

As a general guide to supplementation and based on people who obtain some sun exposure but do not achieve the recommended level of exposure:

  • under 70 years at least 600 IU per day
  • over 70 years at least 800 IU per day
  • for sun avoiders or people at risk of vitamin D deficiency higher doses may be required of 1,000–2,000 IU per day
  • for people with moderate to severe vitamin D deficiency (levels lower than 30 nmol/L) 3,000–5,000 IU per day may be required for 6–12 weeks to raise the vitamin D level quickly, followed by a maintenance dose of 1,000–2,000 IU per day. This should be supervised by their doctor.

For Your Customers

It is very important to raise the issue of bone health with customers who may have low vitamin D or other risk factors for osteoporosis. This includes anyone over 50 years who has experienced a fracture from a minor fall.

Encourage them to take the Know Your Bones online self-assessment introduced by Osteoporosis Australia and The Garvan Institute of Medical Research.

It provides users with a report and risk review which they can take to their doctor to discuss. It can provide an important first step and ensure patients are properly identified and investigated for osteoporosis.

The website has received over 75,000 visits in the first year. It’s something customers can complete at home and is easy to recommend:

Greg Lyubomirsky, CEO Osteoporosis Australia

Share this article:

Articles you might be interested in

Scroll To Top