||Rising awareness about the potential link between vitamin D deficiency and adverse health outcomes has seen an increase in the rate of vitamin D testing in developed countries. The cost of a single vitamin D test is moderate (e.g., $61.32 in British Colombia) but the elevated testing rate contributes to substantial healthcare costs. Concern over rising costs led to reform in testing coverage in 2010 in Ontario, followed by other provinces. The changes in Ontario were based on a 2010 report by the Ontario Health Technology Advisory Committee (OHTAC) on the clinical utility of vitamin D testing (reviewed in this report). Despite a lack of direct evidence on testing, a recommendation was made against providing testing for the general population. Tests are now indicated only for individuals with specific conditions (i.e., osteoporosis, rickets, osteomalacia, malabsorption syndromes, renal disease, and individuals taking medications that may affect vitamin D status). The Endocrine Society and Osteoporosis Canada also recommend against screening for low risk individuals. There is a lack of evidence to suggest that the rise in test frequency has translated into improved healthcare practices. For example, the temporal increase in testing in Australia has not resulted in improved osteoporosis detection in women aged 45 to 74. There is also a lack of evidence on the cost-effectiveness of testing. In light of the rise in test frequency, assay and cut-off inconsistency, and the lack of evidence for the utility of testing, this report will investigate the clinical and cost-effectiveness of testing in the general population.