Those taking biotin PLEASE take note! Biotin (vitamin B7) is a common component of immunoassays (a technique for measuring blood serum levels) and a small study has shown an alarming impact on the accuracy of some commonly performed blood tests. Biotin supplements are commonly taken to reduce nail splitting for those on Ibrutinib therapy and it is regularly taken for other reasons.
The current best recommended practice is to cease taking biotin at least 72 hours prior to a scheduled blood test and allowing a week to be absolutely certain. Don't forget other possible sources of biotin, including B-complex vitamins, Coenzyme R, Dietary supplements for hair, skin, or nail growth, Multivitamins, Prenatal vitamins,
Vitamin B7 supplements, Vitamin H.
Biotin use can also interfere with testing to see if you have had a heart attack, so please mention you are taking high dose biotin if you have this test: healthunlocked.com/cllsuppo...
From MedPageToday: medpagetoday.com/Endocrinol...
Biotin supplements taken at common over-the-counter doses can can interfere with the results of certain hormone assays, giving falsely high or low results that could lead to a misdiagnosis, researchers reported.
In six healthy adults taking 10 mg/day of biotin for 1 week, biotin-associated interference was found in nine of 23 biotinylated assays (39%), compared with zero of 14 non-biotinylated assays (P=0.007 for comparison), according to Danni Li, PhD, of the University of Minnesota in Minneapolis, and colleagues.
:
The blood samples were sent to four different clinical laboratories using different diagnostic systems. Assays were performed to assess levels of nine hormones: thyroid-stimulating hormone, total thyroxine, total triiodothyronine, free thyroxine, free triiodothyronine, parathyroid hormone, prolactin, N-terminal pro-brain natriuretic peptide, and 25-hydroxyvitamin D. Assays were also performed for two non-hormones: prostate-specific antigen and ferritin. (My emphasis)
In this small study, a 37% reduction from baseline was noted in thyroid-stimulating hormone levels with one test method and a whopping 94% reduction from baseline with another.
The results from a further test raised concerns with the possible failure to identify congestive heart failure.
The researchers suggested that "It may be advisable for patients to stop taking biotin, preferably for a week as studied herein, before undergoing laboratory testing. Alternatively, in the presence of biotin ingestion, non-biotinylated assays would be preferred."
Note that "the minimal dose and duration required to alter test results remains undetermined."
Update June 2018
FDA Warns that Biotin May Affect Some Lab Test Results
The FDA urges the general public to that know that biotin is found in many over-the-counter supplements in levels that may interfere with laboratory tests. Examples include:
B-complex vitamins
Coenzyme R
Dietary supplements for hair, skin, or nail growth
Multivitamins
Prenatal vitamins
Vitamin B7 supplements
Vitamin H
Patients should tell their healthcare practitioners if they are taking or plan to take biotin or a supplement containing biotin, and consider the possibility that biotin was the cause of test results that don't seem to make sense. Healthcare practitioners may advise their patients to discontinue taking biotin supplements a few days before having lab tests done.
labtestsonline.org/news/fda...
Further discussion: healthunlocked.com/cllsuppo...
JustLabScientist explained what blood tests are affected in a July 2019 reply thus:
"Biotin interferes with some very important blood tests because biotin and streotavidin, which binds to biotin, are used in the detection scheme for many things—such as hormones, tumor markers, vitamin assays, infectious disease tests (like hepatitis, HIV, etc), iron/iron binding, ferritin, cardiac tests, many antibody tests, and others.
Tests that are not affected are basic things like blood cell counts (CBC), glucose, cholesterol, creatinine, enzymes, electrolytes. However, sometimes doctors add tests to orders and the sample already in the lab gets used for that additional testing. So, it’s best just to stop for a week before regardless of what test is ordered.
Supplementing biotin prior to having blood drawn can cause the results to be erroneously high or low, depending upon the specific design of the test. Different lab test manufacturers design differently. Since you don’t know exactly which test is used, it’s best to be off biotin supplements for a week prior to blood collection.
I hope this helps. If you have a question about a specific type of test, I’d be happy to try to answer it for you."
Neil