The rise and rise of vitamin D testing

Moynihan and colleagues’ report highlights the increasing trend for overdiagnosis, particularly of endocrine disorders. Similar concerns exist for overdiagnosis and overtreatment of vitamin D deficiency. Currently, the appropriate timing and frequency of testing for the diagnosis of vitamin D deficiency is unclear. The cost of testing in Australia increased from $A1m (£0.66m; €0.83m; $1m) in 2000 to $95.6m in 2010, on average 59% each year. Similarly, in Ontario, Canada, testing increased 25-fold from 2004 to 2010. Projections suggest that $C150m (£95m; €120m; $147m) will be spent on vitamin D testing in 2012, up from $38m in 2009. Similarly, the UK has seen a sixfold increase in such tests between 2007 and 2010.