Vitamin D supplementation and testing in the UK: costly but ineffective?

Vitamin D: review of physiology and clinical uses

Interest in vitamin D has increased within the scientific community due to the impact of osteoporosis in the aging population. Vitamin D receptors are present in many tissues and low vitamin D status has been associated with many diseases in observational studies. There was hope that enhanced vitamin D provision might help prevent and treat some widespread disorders. Some of these hopes have been refuted by the results of recent large and well-conducted randomized trials. This review provides an overview of the basic physiology of vitamin D and an update on the evidence base for its clinical applications.

Health, financial and environmental impacts of unnecessary vitamin D testing: a triple bottom line assessment adapted for healthcare

OBJECTIVE

To undertake an assessment of the health, financial and environmental impacts of a well-recognised example of low-value care; inappropriate vitamin D testing.

DESIGN

Combination of systematic literature search, analysis of routinely collected healthcare data and environmental analysis.

SETTING

Australian healthcare system.

PARTICIPANTS

Population of Australia.

OUTCOME MEASURES

We took a sustainability approach, measuring the health, financial and environmental impacts of a specific healthcare activity. Unnecessary vitamin D testing rates were estimated from best available published literature; by definition, these provide no gain in health outcomes (in contrast to appropriate/necessary tests). Australian population-based test numbers and healthcare costs were obtained from Medicare for vitamin D pathology services. Carbon emissions in kg CO₂e were estimated using data from our previous study of the carbon footprint of common pathology tests. We distinguished between tests ordered as the primary test and those ordered as an add-on to other tests, as many may be done in conjunction with other tests. We conducted base case (8% being the primary reason for the blood test) and sensitivity (12% primary test) analyses.

RESULTS

There were a total of 4 457 657 Medicare-funded vitamin D tests in 2020, on average one test for every six Australians, an 11.8% increase from the mean 2018-2019 total. From our literature review, 76.5% of Australia's vitamin D tests provide no net health benefit, equating to 3 410 108 unnecessary tests in 2020. Total costs of unnecessary tests to Medicare amounted to >$A87 000 000. The 2020 carbon footprint of unnecessary vitamin D tests was 28 576 kg (base case) and 42 012 kg (sensitivity) CO₂e, equivalent to driving ~160 000-230 000 km in a standard passenger car.

CONCLUSIONS

Unnecessary vitamin D testing contributes to avoidable CO₂e emissions and healthcare costs. While the footprint of this example is relatively small, the potential to realise environmental cobenefits by reducing low-value care more broadly is significant.

[Adequacy of the prescription of vitamin D in Primary Care]

OBJECTIVES

To evaluate the adequacy of vitamin D treatment based on clinic evidence in a Primary Care Center as well as to analyze some characteristics of the prescriptions made.

MATERIALS AND METHODS

Descriptive cross-sectional study. Primary Care. Patients above 14 years old with vitamin D prescription. Main variable was the therapeutic adequacy with vitamin D compounds (adequacy was considered when there was a clinical indication for treatment and blood vitamin D levels below 20ng/ml). Other clinical variables were collected. Frequency and association measures were used for statistical analysis. Level of statistical significance was considered <0.05.

RESULTS

430 patients, 346 women (80.5%, 95% CI=77-84). Record of vitamin D values in 216 (50.2%, 95% CI=45-55). Screening/treatment indications in 219 patients (50.9%, 95% CI=46-56), of those in 150 patients vitamin D values were recorded (68.5%, 95% CI=62-75), average (±SD) was 21.22±12ng/ml, deficiency criteria in 86 (57.3%, 95% CI=51-64), insufficiency in 37 (24.7%, 95% CI=19-30) and sufficiency in 27 (18%, 95% CI=13-23). 86 patients (20%, 95% CI=16-24) had treatment indications plus vitamin D deficiency with no differences between genders.

CONCLUSIONS

Only 20% of the patients had treatment indications plus vitamin D deficiency. Female predominance. Just over half had indications for screening of serological vitamin D values and/or indications for treatment with vitamin D compounds.