Vitamin D testing

Information sheet for patients

Is this information for you?

This information is for you if you:

  • are considering having a test for vitamin D deficiency
  • are vitamin D deficient and have been taking vitamin D tablets, capsules or injections.       
  •  Vitamin D is a hormone that controls calcium levels in the blood. It is important for your bone health and the function of your nerves and muscles.1
  • You need to be exposed to the sun for your body to produce an active form of vitamin D. However, because your body can only produce a certain amount of vitamin D at a time, staying in the sun for longer than necessary will not produce more vitamin D, but will increase your risk of skin cancer.
  • Your vitamin D levels change with the seasons.
  • People with low vitamin D levels may be at risk of developing bone conditions such as osteoporosis, osteomalacia and rickets.
  • If you are concerned about your vitamin D levels, speak to your general practitioner (GP).
  • Your GP may decide to test your vitamin D levels2 if you:
    • have osteoporosis/osteomalacia, or symptoms of either of these
    • have malabsorption (for example, cystic fibrosis, untreated coeliac disease, short bowel syndrome or bariatric surgery)
    • have deeply pigmented skin
    • have experienced chronic lack of sun exposure (for example, you have been confined to indoors for a long time)
    • are taking medications known to decreased vitamin D absorption (for example, anticonvulsants)
    • have chronic kidney or renal failure or have received a kidney transplant
    • have other conditions that your GP thinks might be caused by low levels of vitamin D.
  • You will not receive a rebate from Medicare for a vitamin D test, unless you meet certain criteria,3 which your GP can explain to you.

GPs do not recommend testing everyone for vitamin D deficiency because:

  • there is no benefit in testing people who are well and not at risk of developing a vitamin D deficiency1
  • there is no agreed ‘ideal’ level of vitamin D because many different factors come into play, including age and people’s metabolism
  • if you are taking a vitamin D supplement and your level is normal, there is no need to have another test.

Is there a link between vitamin D and conditions like depression and diseases like bowel cancer?

Vitamin D levels may be linked to depression and some medical conditions. If you have specific concerns or symptoms, talk to your GP, who will be able to advise you about the link between particular conditions and vitamin D.

If I am taking a vitamin D supplement, when should I get re-tested?

Wait at least three months before having another test.2

What else can I do to maintain my vitamin D and healthy bones?

There are many ways of increasing your vitamin D levels, including:1

  • exercising outside (but don’t stay out in the sun too long)
  • doing a variety of exercise, including cardio and strength training
  • maintaining a healthy weight
  • eating foods rich in vitamin D (such as salmon, tuna, sardines, egg yolk, fortified cereals) and foods rich in calcium (such as milk, yoghurt, cheese, beans, lentils, fruits, nuts and seeds)
  • preventing falls
  • giving up smoking
  • reducing your consumption of alcohol.
  • If you wish to have your vitamin D level tested and you do not meet the criteria for a Medicare rebate, you will have to pay for your test. We recommend that you investigate the costs and talk to your GP about whether the results would change management of any conditions you have.
  • Your body is only able to absorb a limited amount of vitamin D at a time, so high-dose supplements will not necessarily increase your vitamin D levels more than other supplements. In addition, they can be expensive and they can also be toxic (although this is rare).
  • If you are worried about your test results or vitamin D levels, please discuss this with your GP.