There is a recommendation to stop taking Vitamin B12 supplements prior to testing for anti-parietal cell and anti-intrinsic factor antibodies, which are used to diagnose conditions like pernicious anemia¹. This discontinuation is necessary because Vitamin B12 supplementation can potentially interfere with the test results by affecting the serum levels of related antibodies¹. Typically, this discontinuation period can range from a few days to a couple of weeks, but specific guidelines may vary depending on the healthcare provider's recommendations. Hence, following the guidance of your healthcare provider regarding the exact period for discontinuation is essential.