In January, 2017, the B vitamin biotin was in the news as a possible breakthrough treatment for multiple sclerosis. This positive news was dampened a bit when the U.S. Food and Drug Administration (FDA) released a warning regarding the safety of biotin on November 28, 2017. The headlines from the warning are a bit misleading as biotin is certainly safe, even at the massive doses being used in multiple sclerosis. The safety concern is that high dosages of biotin can significantly interfere with certain laboratory tests. This interference can lead to dangerously incorrect conclusions.


Several lab tests utilize biotin to bind to specific proteins in the blood sample that can then be measured to determine the diagnosis of cancer, heart disease, thyroid disorders, and even pregnancy. With high dosages, the presence of biotin in the blood can interfere with the test results causing either falsely low or high results. That can be a problem.


Before discussing this issue further, let’s take a quick look at what is biotin and why are people taking it at high dosages.


Background Data:

Biotin is a member of the B vitamin family even though it can be produced by bacteria in the gut. It functions in the manufacture and utilization of fats and amino acids. A biotin deficiency in adults is characterized dry, scaly skin; nausea; loss of appetite; and seborrhea. In infants under six months of age, the symptoms are seborrheic dermatitis (cradle cap), persistent diaper rash, and alopecia (hair loss).


Biotin is a popular recommendation to increase the strength of nails and promote health hair. Early research on biotin in this application came from the veterinary literature. Biotin was shown to increase the strength and hardness of hooves in pigs and horses. Human studies have shown that biotin supplementation (2,500 mcg per day) can produce a 25% increase in the thickness of the nail plate in patients diagnosed with brittle nails of unknown cause and up to 91% of patients taking this dosage will experience definite improvement. However, despite its impressive results in people with brittle nails, biotin supplementation has not been shown to produce much impact on nail strength in people with normal nail strength.


In regards to the beneficial effects of biotin on the health of hair, it possibly reflects an ability to improve the metabolism of scalp oils similar to biotin’s effects in seborrheic dermatitis, a common condition that is associated with excessive oiliness (seborrhea) and dandruff. The dandruff of seborrhea may be yellowish and either dry or greasy. In addition, scaly bumps may coalesce to form large plaques or patches. Seborrheic dermatitis usually occurs either in infancy (usually between two and twelve weeks of age) or in the middle-aged or elderly and has a prognosis of lifelong recurrence.


In infancy, seborrheic dermatitis is known as cradle cap. Several case histories have demonstrated successful treatment of cradle cap with biotin by either giving the mother the biotin if the baby is being breast-fed or directly to the infant. When I was a medical student, I remember quite a dramatic case of cradle cap clearing up almost immediately with supplementation with a liquid biotin supplement given to the baby. It made quite an impression on me. Cases of persistent diaper rash have also responded as well.


In adults with seborrheic dermatitis, treatment with biotin alone is usually of no value, it probably requires not just biotin, but also other necessary B-vitamins as they all work together synergistically.


Another use of biotin is in diabetes. There is a lot of scientific evidence showing biotin supplementation can enhance insulin sensitivity and improve the utilization of blood sugar.  This improvement is thought to be the result of an increase the activity of the enzyme glucokinase – an enzyme involved in the utilization of blood sugar by the liver. With activation of this enzyme, the liver pulls glucose from the blood and utilizes it in metabolism. In one study, 8 mg of biotin twice daily day resulted in significant lowering of fasting blood sugar levels and improvements in blood glucose control in type 1 diabetics. Several other studies have shown biotin alone and in combination with chromium can be helpful in improving blood sugar control and lower blood triglyceride levels in patients with type 2 diabetes. High dose biotin has also been reported to be very helpful in the treatment of severe diabetic nerve disease (diabetic neuropathy).


Scientists have been investigating biotin’s possible use in multiple sclerosis (MS) for quite some time, especially since low levels of biotin were found in the spinal fluid in patients with MS back in 1999. MS is a progressive nerve disease where the myelin sheath that surrounds nerve fibers degenerates leading to loss of nerve function. Since biotin is required to utilize the fats used in making the myelin sheath as well as participates in cellular energy in nerve cells, it may prove to be helpful. The initial clinical studies with biotin and MS have been conducted in France and have utilized biotin at the massive dosage of 300 mg per day. The first, published in March 2015 in Multiple Sclerosis and Related Disorders, was a pilot study of 23 patients, most showing some measure of improvement after taking the drug. In a larger randomized controlled trial, published in Multiple Sclerosis Journal in November 2016, 154 participants received either 300 mg of biotin or a placebo for one year. Among the patients taking biotin, none of the patients taking the biotin worsened and 12.6 percent of them had improvements in their disability at the end of the year. In contrast, none of the people in the placebo group showed improvement and most worsened. The significance of a one in eight people seeing improvement is that biotin treatment is the first ever shown to actually reverse the progression of the disease.


However, not all of the studies have shown benefit. A smaller study conducted at the Multiple Sclerosis Treatment and Research Center at the Minneapolis Clinic of Neurology with 43 patients with progressive MS failed to show any real benefit of biotin therapy in MS. Currently, there are efforts to recruit 600 patients from 80 study centers around North America and Europe in order to conduct a larger double-blind study to determine the effectiveness of biotin therapy in MS.


New Data:

The FDA is doing its job in alerting the public, health care providers, lab personnel, and lab test developers that biotin can significantly interfere with certain lab tests. While there are many valid points about the FDA warning, some perspective is required. Certainly, at the massive dosages being used in the medical treatment of MS (i.e., 300 mg per day), biotin interference is definitely going to be a problem. But, what about at dosages less than 10 mg per day?


The only real published data that has looked at this question was published in January, 2017 in the Annals of Clinical Biochemisty. Here is what that study demonstrated. Yes, at 300 mg per day, there is significant interference in test results that could be a major issue. Anyone taking these high dosages of biotin needs to alert their physician. But, at dosage ranges of 5-10 mg of biotin there were only a few tests where interference was significant and it was based primarily on the test method. There are different ways of measuring these proteins and interference is somewhat dependent on the method, e.g., Roche immunoassays are particularly vulnerable while those from Siemens are not. The tests that showed the most concern at dosage of 10 mg per day are those anti-thyroid antibodies used in the diagnosis of thyroid disease and troponin, a blood protein used to differentiate between an angina attack versus a heart attack (myocardial infarction). The interference with troponin is a big concern because it may mean not getting the right diagnosis in an emergency situation with the patient being treated for angina instead of a heart attack.


Here is the takeaway from all the above:

  • Know the level of biotin you are consumer. Biotin is not only available on its own as a supplement, but is also found in multivitamins and supplements for hair, skin, and nail health.
  • Biotin at dosages greater than 5 mg may interfere with laboratory tests. If you have had a lab test done and are concerned about the results, talk to your health care provider about the possibility of biotin interference. They can talk to the lab to determine what methods of analysis were used and judge the appropriateness of retesting after washing out the biotin from your system. No supplementation for 2 weeks should be sufficient.
  • Tell your physician you are taking biotin, especially if you are being treated for angina or thyroid disease and if you are taking dosages greater than 10 mg daily.


Here is another consideration, while high dosages of biotin supplements lead to interference in laboratory tests, so do low levels of biotin in the blood. This problem has also not been fully defined. It may be that labs will need to factor in biotin levels when reporting any result from a test that uses biotin technology.



Let me provide some guidelines of use for biotin. The estimated safe and adequate dietary intake for adults is 30-100 mcg. To promote stronger nails and healthy hair a typical dosage range is 1,000 to 3,000 mcg per day. In the treatment of seborrheic dermatitis, the dosage to administer to nursing mothers is 3,000 mcg twice daily. For infants not being breast-fed, an effective dosage is estimated to be 100-300 mcg daily. In the treatment of diabetes and diabetic neuropathy, dosages of 4 to 8 mg twice daily have been used successfully.


Biotin is extremely safe and no side effects have ever been reported with biotin supplementation. Individuals with diabetes should use caution when using high dosages (e.g., greater than 4 mg) as it may produce reductions in blood sugar levels requiring changes in the dosage of insulin or other medications.


As far as interactions, the biggest one is the problem with antibiotics. Since antibiotics may decrease biotin levels due to destruction of biotin-producing bacteria in the intestines, it is important to utilize probiotics during antibiotic use and supplement with at least the recommended dietary intake (RDI) for biotin. Alcohol also inhibits the absorption and utilization of biotin.


As for some positive interactions, biotin works synergistically with other B-vitamins as well as coenzyme Q10 and carnitine.



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