Reductions in folate testing have been proposed on the basis of low levels of deficiency in fortified populations. The very low deficiency rate in Canada signals that reconsideration of the necessity of folate testing nationwide may be required, particularly in populations that could potentially benefit from targeted supplementation. Supplementation has not been linked to any adverse side-effects apart from potentially masking underlying vitamin B12 deficiency, and possible central nervous system and gastrointestinal side effects at 15 times the current tolerable upper limit of 1000 micrograms; however, the potential harms of foregoing testing for supplementation are unknown. The direct cost of folate testing is substantially higher than supplementation, although no formal cost-effectiveness analyses have been conducted. As well, the clinical utility of folate testing is unclear.
This review will address lack of clarity surrounding the clinical utility and resource implications of folate testing, as well as the uncertainty regarding the appropriate analytical methods and clinical indications for routine folate testing.
Disclaimer: The Rapid Response Service is an information service for those involved in planning and providing health care in Canada. Rapid responses are based on a limited literature search and are not comprehensive, systematic reviews. The intent is to provide a list of sources of the best evidence on the topic that CADTH could identify using all reasonable efforts within the time allowed. Rapid responses should be considered along with other types of information and health care considerations. The information included in this response is not intended to replace professional medical advice, nor should it be construed as a recommendation for or against the use of a particular health technology. Readers are also cautioned that a lack of good quality evidence does not necessarily mean a lack of effectiveness particularly in the case of new and emerging health technologies, for which little information can be found, but which may in future prove to be effective. While CADTH has taken care in the preparation of the report to ensure that its contents are accurate, complete and up to date, CADTH does not make any guarantee to that effect. CADTH is not liable for any loss or damages resulting from use of the information in the report.