These guidelines aim to provide an evidence-based approach to the diagnosis and management of cobalamin and folate disorders. However, such evidence, particularly in the form of randomised controlled trials, is lacking. As a result, these guidelines provide a pragmatic approach to the testing and treatment of cobalamin and folate disorders.

Declaration of Interests

The BSH paid the expenses incurred during the writing of this guidance. None of the authors had conflicts of interest to declare. All authors have made a declaration of interests to the BSH and Task Force Chairs which may be viewed on request.