Curbing Unnecessary Vitamin D Testing

Vitamin D testing is frequently overused across U.S. health systems, with much of it occurring outside the bounds of evidence-based clinical indications. Despite clear guidance from the Endocrine Society and the U.S. Centers for Medicare and Medicaid Services, routine screening in low-risk populations remains common and costly. Within Oregon, vitamin D testing has been identified as one of the top 15 low-value services, representing a substantial opportunity for cost savings and practice alignment. In an effort to reduce the volume of low-value vitamin D testing across a three-hospital academic health system, a multidisciplinary working group designed and implemented an electronic health record best practice advisory to fire at the point of order entry when a vitamin D test was attempted without an approved indication. The initiative involved implementing a targeted clinical decision support intervention, aligned with evidence-based diagnostic coding curated using the U.S. Centers for Medicare and Medicaid Services coverage criteria and reinforced by coordinated communication and measurement infrastructure. The proportion of indicated vitamin D tests increased from 45% (939 of 2060) in the final month pre intervention to more than 88% (1194 of 1354) at 90 days post intervention, and remained above 90% (1381 of 1531) at 1 year post go-live. Improvements were consistent across payer types, age groups, and locations of care, with the largest gains seen in outpatient and Medicaid populations. In absolute terms, the number of vitamin D tests decreased by 25.3% (to 16,530 from 22,129) when comparing the 12 months pre intervention with the 12 months post intervention. Along with this decrease was an estimated cost savings of nearly US$112,000. The intervention significantly improved ordering appropriateness while maintaining access to necessary testing. It required no additional staffing or investment in new infrastructure. Provider feedback highlighted the value of peer engagement, transparency in metric definitions, and responsiveness to edge cases. Data revealed attempts to bypass the best practice advisory using unspecified diagnosis codes. A simple, well-targeted clinical decision support tool, paired with strategic communication and disciplined measurement, can lead to meaningful reductions in low-value vitamin D testing. Sustained improvement depends on transparent metrics, engaged leadership, and a willingness to challenge entrenched ordering habits while remaining attentive to clinical nuance.