Li CF, et al. - In this retrospective study performed within Kaiser Permanente Northern California, researchers assessed the yield of vitamin D testing in women identified by their providers for the start of osteoporosis therapy. Participants included women (aged 50 to 89 years) who started oral bisphosphonate therapy (alendronate, risedronate, or ibandronate) from 2010 to 2013. A low 25-hydroxy-vitamin D (25OHD) level (defined as less than 20 ng/mL based on the 2011 Institute of Medicine report) was evaluated as primary outcome. Among women targeted for osteoporosis therapy, the overall yield of finding a low 25OHD level was one in five. Nonwhite race/ethnicity and high BMI were found to increase the yield. The risk of low 25OHD was approximately twice in black and Hispanic women vs white (non-Hispanic) women, while an independent contribution of obesity to higher risk was also evident. Findings revealed the beneficial impact of vitamin D repletion in a large subset of women identified for bisphosphonate therapy. The costs related to widespread 25OHD testing were found to be escalating, especially when generally applied, and therefore, targeted 25OHD testing was supported when optimizing bone health in high-risk populations not earlier screened or treated for vitamin D deficiency.