Biotin is a nutrient that is often associated with hair and nail health - you can buy many different “hair and nail” supplements with high doses of biotin.  Unfortunately, as we will see, this is a false claim - your hair would however benefit from a diet rich in protein, vitamin C, antioxidants, and minerals.  If you have cupboards full of these supplements, it’s time to trade them for a nutrient-dense diet.  If your hair and nails are still weak and brittle after addressing your diet, it’s time to check for other causes with your healthcare team.  

Now that we have addressed the myth of biotin as a “hair nutrient” let’s explore how biotin really supports our health. 

What is Biotin & What Does it Do?

Biotin is another of our water-soluble, B-complex vitamins.  When it goes to work, biotin acts as an “essential cofactor”, which is an ingredient that allows a chemical reaction to move forward.  It also plays a role in regulating gene expression - turning parts of your DNA “on & off” in response to your immediate biological needs. (1)

In this second role, biotin helps to unwind segments of your DNA so it can be copied and then turned into proteins.  This process involves tiny chemical spools called histones.  When your DNA is stored in the nucleus of your cells, it is wound tightly around these chemical spools like thread.  This keeps it organized and ready for use.  Our bodies are full of so many clever strategies! 

Biotin Deficiency: 

Luckily, biotin deficiency is quite rare and is only seen in three scenarios: prolonged IV feeding without added biotin, infants fed an elemental formula that doesn’t contain biotin, and in those who eat a lot of raw egg whites.  The protein avidin in raw egg whites can bind to biotin, preventing us from absorbing the vitamin - cooking changes the structure of avidin and prevents this binding. (1)

In cases of biotin deficiency, we see the following symptoms: 

• Hair loss (remember those “hair vitamins”?)

• Scaly red rash around the eyes, nose, mouth, and genitals 

• Depression

• Lethargy

• Hallucinations

• Numbness and tingling of the extremities

• Ataxia - lack of coordination (2)

• Seizures

Treatment of Disease: 

Now that we can identify an overt deficiency of biotin, let’s look at its role in other diseases.

Metabolic Disorders: 

There are several different hereditary disorders that can interfere with biotin activity in the body.  Biotin supplementation is key in both the prevention and treatment of the symptoms of these conditions.  These disorders present early in life and many are screened for by the heel poke test performed on infants soon after birth.  These conditions include: (1)

• Biotinidase deficiency

• Holocarboxylase synthetase deficiency

• Biotin transport deficiency

• Phenylketonuria (PKU)

• Biotin-responsive basal ganglia disease

Congenital Anomalies: 

During pregnancy, the need for biotin increases, and “current research indicates that at least one-third of women develop marginal biotin deficiency during pregnancy.” (3)  This deficiency may be linked with changes in the development of the fetus such as cleft palate and under-developed arms and legs. (1)  It is suggested by some that biotin supplementation should be encouraged for pregnancy and those who may become pregnant.  This recommendation already exists for folate. 

Multiple Sclerosis: 

Research into the role biotin may play in MS is ongoing.  MS is an autoimmune condition of the nervous system.  Due to biotin’s role in the metabolism of fatty acids, particularly in pathways needed to form the nerve-insulating substance myelin, it is proposed that biotin may help repair some of the damage done by MS.  Myelin in particular is destroyed by the inflammatory processes of MS. 

While this sounds like a good focus for treatment, the research is mixed.  Two meta-analyses evaluating the role of high-dose biotin in MS deliver conflicting conclusions, one recommending high-dose biotin therapy and one discouraging it. (4) (5)  This is due to high dose biotin’s ability to interfere with test results used to monitor MS disease activity, as well as unclear evidence regarding symptom improvement.  More research is needed. 

Diabetes: 

Since biotin deficiency has been shown to cause issues in glucose metabolism, biotin has been studied as a potential adjunctive treatment to be used with other medications.  Several studies have been done combining biotin and chromium.  These studies show a significant improvement in glucose metabolism; however, chromium alone also reduces blood glucose levels in those with diabetes and pre-diabetes. (6)

One randomized placebo controlled study looking at biotin’s role in diabetes gives the following conclusion: 

“Biotin treatment had no significant effects on cholesterol, glucose and insulin in either the diabetic or nondiabetic subjects. We conclude that pharmacological doses of biotin decrease hypertriglyceridemia. The triglyceride-lowering effect of biotin suggests that biotin could be used in the treatment of hypertriglyceridemia.” (7)

Brittle Fingernails and Hair Loss: 

Unfortunately, as I mentioned above, simply adding more biotin cannot create thick and luxurious locks and diamond-strong nails.  Here is the conclusion from a review of studies done on biotin for hair and nail health: 

“Though its use as a hair and nail growth supplement is prevalent, research demonstrating the efficacy of biotin is limited. In cases of acquired and inherited causes of biotin deficiency as well as pathologies, such as brittle nail syndrome or uncombable hair, biotin supplementation may be of benefit. However, we propose these cases are uncommon and that there is a lack of sufficient evidence for supplementation in healthy individuals.” (8)

Toxicity: 

Luckily, “[b]iotin is not known to be toxic.” (1)  Therefore no upper limit (UL) has been set for this nutrient. 

Where to Find Biotin: 

Outside of supplements, biotin is found in many different food sources.  Unfortunately, “[f]ood composition tables for biotin are incomplete.” (1) This means we do not have all the information we need to strategically increase our dietary biotin.  We do know some sources, and hopefully, this gap in our knowledge will be filled in soon. 

Foods particularly rich in biotin: (1)

• Egg yolk

• Liver

• Yeast

• Avocado

• Pork

• Salmon

Applications:

Our takeaways this week are: 

1. While it is not the magic nutrient for hair and nail health that it is advertised to be, biotin is essential for life. 

2. There are many consequences to biotin deficiency; however, it is rare outside of metabolic disorders, certain biotin deficient medical diets, and the long-term consumption of raw egg whites. 

3. Biotin supplementation may be needed during pregnancy to prevent congenital anomalies such as cleft palate and under-developed arms and legs. 

4. There is still much more we need to explore about this nutrient. 

Daily Intake:

There is no RDA (minimum amount to avoid deficiency) for biotin at this time, and there is no UL (upper limit) for biotin intake.  What we do have is an AI (adequate intake) level of 30 mcg daily.  The Linus Pauling Institute supports this recommendation and suggests that a varied diet may provide this level of biotin on its own, but always recommends a multivitamin as part of a healthy diet. (1)  I see no evidence for adjusting this recommendation at this time, but I do hope we learn more about this nutrient soon. 

Medication Interactions:

Medications that can increase a need for biotin in the diet include (1): 

• Anticonvulsant medications

• Sulfa drugs

• Long-term antibiotic use

• High dose B5

• High dose alpha-lipoic acid

At this time, biotin has not been shown to interfere with any other medications. 

Next week: 

Our next B-complex vitamin to explore is folate (B9).

Yes, we are skipping B8, inositol, just as we did with vitamin B4 - adenine.  

We can produce inositol from the carbohydrates we eat in our diet; this means it is not a vitamin after all.  Vitamins are classified as naturally occurring, non-calorie-producing nutrients that are needed for life that are not found on the periodic table or made by our bodies.

To our health!

References: 

1. Higdon, J, “Biotin” Linus Pauling Institute, 2000; last update: October 21, 2015; accessed October 28, 2021; https://lpi.oregonstate.edu/mic/vitamins/biotin

2. Mayo Clinic, “Ataxia - Symptoms and causes”, June 3, 2020, accessed November 3, 2021,https://www.mayoclinic.org/diseases-conditions/ataxia/symptoms-causes/syc-20355652

3. Mock DM. Biotin. In: Ross AC, Caballero B, Cousins RJ, Tucker KL, Ziegler TR, eds. Modern Nutrition in Health and Disease. 11th ed.: Lippincott Williams & Wilkins; 2014:390-398.

4. Espiritu AI, Remalante-Rayco PPM. High-dose biotin for multiple sclerosis: A systematic review and meta-analyses of randomized controlled trials. Mult Scler Relat Disord. 2021 Oct;55:103159. doi: 10.1016/j.msard.2021.103159. Epub 2021 Jul 21. PMID: 34332461.

5. Cree BAC, Cutter G, Wolinsky JS, Freedman MS, Comi G, Giovannoni G, Hartung HP, Arnold D, Kuhle J, Block V, Munschauer FE, Sedel F, Lublin FD; SPI2 investigative teams. Safety and efficacy of MD1003 (high-dose biotin) in patients with progressive multiple sclerosis (SPI2): a randomised, double-blind, placebo-controlled, phase 3 trial. Lancet Neurol. 2020 Dec;19(12):988-997. doi: 10.1016/S1474-4422(20)30347-1. Epub 2020 Oct 23. PMID: 33222767.

6. San Mauro-Martin I, Ruiz-León AM, Camina-Martín MA, Garicano-Vilar E, Collado-Yurrita L, Mateo-Silleras Bd, Redondo Del Río Mde P. [Chromium supplementation in patients with type 2 diabetes and high risk of type 2 diabetes: a meta-analysis of randomized controlled trials]. Nutr Hosp. 2016 Feb 16;33(1):27. Spanish. doi: 10.20960/nh.v33i1.27. PMID: 27019254.

7. Revilla-Monsalve C, Zendejas-Ruiz I, Islas-Andrade S, Báez-Saldaña A, Palomino-Garibay MA, Hernández-Quiróz PM, Fernandez-Mejia C. Biotin supplementation reduces plasma triacylglycerol and VLDL in type 2 diabetic patients and in nondiabetic subjects with hypertriglyceridemia. Biomed Pharmacother. 2006 May;60(4):182-5. doi: 10.1016/j.biopha.2006.03.005. Epub 2006 Mar 31. PMID: 16677798.

8. Patel DP, Swink SM, Castelo-Soccio L. A Review of the Use of Biotin for Hair Loss. Skin Appendage Disord. 2017 Aug;3(3):166-169. doi: 10.1159/000462981. Epub 2017 Apr 27. PMID: 28879195; PMCID: PMC5582478.