Vitamin D testing should not be routinely performed in pregnant women, according to updated Australian clinical guidelines.

Routine testing and subsequent supplementation in pregnancy is not supported by evidence and should cease because the benefits and harms of vitamin D supplementation are not clear, say the authors of the updated clinical practice guidelines on pregnancy care published in the MJA.

The guidelines – which are based on systematic reviews of evidence – recommend:

• Clinicians do not routinely recommend testing for vitamin D status in the absence of a presence of a specific indication (evidence-based recommendation);
• If testing is performed, supplementation should be only recommended when vitamin D levels fall below 50 nmol/L (practice point).

The past decade has seen strong interest in vitamin D deficiency in the community with anecdotal evidence suggesting it is common for pregnant women to be routinely tested and told to take supplements, write the guideline authors, led by Professor Caroline Homer, director of the Centre for Midwifery, Child and Family Health, UTS Sydney.

They note that recent studies have shown that 23% of Australian adults have low vitamin D levels, particularly people living in the south-eastern states of Australia and in major cities and more often in winter.

“However, there is limited evidence supporting testing of all women for vitamin D status in pregnancy and lack of clarity regarding the benefits and harms of supplementation in pregnancy,” they write.

Testing for vitamin D is expensive and supplementation involves an additional cost for women, they add.

The updated document combines two earlier editions of the Clinical Practice Guidelines: Antenatal Care published in 2012 and 2014.

“The revised recommendation in the guidelines provides an opportunity to be more directive and specifically advises clinicians not to routinely recommend testing for vitamin D status to pregnant women in the absence of a specific indication.”