Vitamin D - Time for a test?

05 July 2023

During winter the dark, gloomy weather makes the call of the couch more appealing than ever – but when’s the last time you checked your Vitamin D levels?

Regardless of calling sunny Australia home, there’s still a high likelihood that your Vitamin D levels may fall short.

What we know

Sunlight on the skin is the natural way to get Vitamin D, but it’s important to be mindful of your level of sun exposure as too much sun could cause skin cancer.

Not many foods contain significant levels of Vitamin D so typically less than 10% of Vitamin D requirements are obtained from food.

Vitamin D2 is found in mushrooms while Vitamin D3 is found in oily fish, liver and eggs as well as being made in the skin by sunlight. Both Vitamin D2 and D3, are converted into 25-hydroxy-vitamin D and this is what the laboratory tests to determine a person’s Vitamin D status.

Side effects of low levels

Studies have shown low Vitamin D levels can contribute to:

  • low-bone density conditions like osteoporosis
  • poor muscle strength
  • poor mental health
  • dementia
  • pre-term birth
  • pre-eclampsia
  • poor cardiovascular and respiratory health
  • type 1 diabetes and other auto-immune diseases
  • cancer
  • premature death

Did you know? Around two-thirds of those over 50 years have osteopenia or osteoporosis. In 2020 alone, osteoporosis caused 173,000 bone fractures in Australia.

Why do we test?

Across October and November 2021, SA Pathology conducted over 40,000 Vitamin D tests and just under half showed insufficient levels.

Dr Helen Martin says, "It’s recommended that adults have 60-160 nmol/L of Vitamin D. A simple blood test can tell you exactly whether you have sufficient for your body to work at its best."

Not as simple as sunshine

Australia has some of the highest levels of sun exposure worldwide, so it’s understandable why many Aussies assume their levels are sufficient.

However, sunscreens with a protection factor of 15 or greater, clothing and weight can all impact the ability to create the vitamin.

It’s the quality of the exposure too. The angle of the sun and the UV index/rays, cloud cover, pollution as well as various personal factors (age, weight, medication) can all contribute to how much Vitamin D is made in the skin.

With so many variables, testing is the only way to establish a person’s levels. 

How do we test?

A small blood sample is the only requirement for Vitamin D testing.

Our metabolic lab team will review your 25-hydroxy-vitamin D levels and provide them to your referring doctor who can then discuss any necessary supplement requirements.

If you’re ready to review your levels, ask your doctor for a referral and bring along to one of our Collection Centres.

Clinicians can find comprehensive ordering information through our Pathology Collection Guide.

General News


Laboratory to Bedside: Why Pathology, Research and Clinical Care Need a Connected Journey

Jill’s perspective on collaborative research and clinical pr...


Declan’s commitment to advancing clinical biochemistry practice

We would like to give a massive congratulations to Declan Ne...


Meet Buzzy

We are excited to introduce our newest member of the team… B...


Newborn Screening program expanded

Newborn Screening program expanded This month, SA Patholog...


Hiss the season

Snakes love to make themselves at home during the warmer wea...