A new study, led by Sunnybrook researchers, has found that criteria-based ordering for vitamin D, while immediately effective to reduce vitamin D testing in the short-term, appears to no longer be reducing unnecessary testing. The research was published May 12th, 2025 in JAMA Internal Medicine.
In 2010, in an effort to reduce unnecessary routine testing, Ontario implemented new criteria limiting publicly-funded vitamin D testing to patients with specific conditions (osteoporosis, osteopenia, rickets, malabsorption syndromes, chronic kidney disease, or those who take medications affecting vitamin D metabolism). The following year vitamin D testing decreased by 82.6 per cent.
“Our research found that after an initial decrease, rates began to rise again. From 2011 to 2023, publicly-funded testing increased annually,” says Dr. William Silverstein, associate scientist and general internist at Sunnybrook Health Sciences Centre. “In 2023, there were 30.2 vitamin D tests performed per 1000 patient visits per month, representing 99.3 per cent of the peak ordering volume in 2009, before the implementation of the new criteria.”
The authors say the increase may be associated with inappropriate ordering to facilitate access, given that patients or providers do not need to show proof of documented conditions or a lack of physician oversight or feedback on testing appropriateness. Increased testing may also be motivated by patient requests and media attention on the association between vitamin D and health concerns.
“The evaluation of the long-term impact of the policy suggests further efforts are needed to improve testing practices,” says Dr. Silverstein, who is also Physician Lead of the Choosing Wisely Committee at Sunnybrook. “This may include better enforcement of this policy (e.g., proving patients have an indication for testing) or amending Ontario’s generic lab requisition to actually remove vitamin D altogether as a default test.”
Research like this is one way Sunnybrook contributes to reducing unnecessary tests and treatments. Sunnybrook is recognized as a Choosing Wisely Canada Hospital at the Leadership Status level — the highest achievement awarded under the national program. Choosing Wisely Canada’s Hospital Designation Program recognizes hospitals that take deliberate action to reduce overuse and demonstrate organizational commitment to minimizing waste and harm.