Vitamin D metabolism and the treatment of vitamin D deficiency have been the source of controversy as learned professional societies from different regions of the world publish diverse guidelines and recommendations. The terminology regarding what constitutes vitamin D “deficiency” or “insufficiency” is disparate, the therapeutic target level of 25hydroxyvitamin D (25OHD) and who should be treated are inconsistent in these recommendations. But, are these valid reasons to abandon routine measurement of 25OHD?

In this debate, I will outline several reasons why the measurement of 25OHD is not over-rated including:
• Analytical precision and bias indicate routine assays are appropriate for diagnostic and therapeutic monitoring purposes.
• Routine screening is not advised so a case-finding strategy is appropriate. This necessitates measurement of 25OHD.
• Vitamin D deficiency is frequently asymptomatic so measurement of 25OHD is appropriate.
• Treatment of vitamin D deficiency is associated with lower rates of falls, hip fracture and non-vertebral fractures. Emerging post hoc meta-analysis data indicates that a threshold target of treatment does exist which is predicated on 25OHD measurement.
• If higher target thresholds of treatment are adopted, more and not less frequent monitoring of treatment will be required.
• Despite diversity of opinion in numerous published guidelines, no individual professional organisation states that measurement of 25OHD is superfluous.

For these reasons, the measurement of 25OHD is not over-rated and the measurement of 25OHD will remain an important component of care in the routine assessment and treatment of patients at risk of falls and fractures in Australasia.