Nationwide project: Appropriate vitamin testing in primary care

In recent years, the number of vitamin D and B12 tests in the general practice has increased, often without an indication. Increasingly, alleged vitamin deficiencies are associated with a broad variety of non-specific symptoms and complaints by patients. Due to this increased perceived importance of vitamin levels, at request of the patient, vitamin levels are increasingly tested by general practitioners (GPs) without clinical indication. A lack of vitamin D and B12 rarely causes these symptoms.

Although the direct harmful effects are limited, this form of medicalization is undesirable. It supports irrational health perceptions in patients, leads to inefficient use of GP consultation and laboratory diagnostics.

This national project aims to support general practitioners to prevent overuse and underuse of vitamin D and Vitamin B12 testing. In previous study*, almost 150 GPs reduced vitamin testing with 20-25%. Participating GPs played a video about vitamin D and B in the waiting room and hang posters. Patients asking for vitamin testing received an educational leaflet. In addition, GPs followed an e-learning and received benchmark information about their vitamin testing requests.

After this successful project, we started spreading this intervention nation-wide.

* View original project


We formed a team with a coordinating GP. The first step was to adapt the intervention to fit the local needs. We arranged that the e-learning was available free of charge for all GPs. We contacted all laboratories to invited them to join our project. Participating laboratories provided benchmark information on request of GPs. Most laboratories also organize routine education on vitamin testing for GPs. These laboratories were willing to promote the project after such educational meetings.

The previous project received feedback on the leaflets, posters and waiting room video. We have used these commentaries to improve these materials.

We reached GPs though newsletters of the Dutch association of GPs and a well-known Dutch research journal for GPs. Other ways to reach GPs was by contacting regional GP collaborations and other local GP associations.

GPs can choose which materials they wanted to used to reduce inappropriate testing.

Learn more

If you are interested or have questions, please contact Eva Verkerk or Tijn Kool.