Biotin—The Importance of Vitamin B7

Dr. Jolene BrightenPublished: Last Reviewed: Sex Hormones Leave a Comment

Looking for better hair, skin, and nails? Biotin is hands down one of the best nutrients to help with strong nails, healthy skin, and luscious locks. But there is a whole lot more to biotin than just looks. 

Biotin (vitamin B7) is one of the eight B vitamins. It is an essential nutrient with myriad functions in the body. Today, we’ll take a closer look at biotin: Where can we find it? Why do we need it? How do we know if we are deficient? We’ll also talk about the best way to include biotin in your routine with diet and supplements.

What is biotin?

According to Medicine Net, the definition of Biotin is:

“A water-soluble B-complex vitamin involved in carbon dioxide transfer and therefore essential to the metabolism of carbohydrate and fat. A balanced diet usually contains enough biotin. Foods with high biotin levels include nuts, cereals, green leafy vegetables and milk.”

Therefore, Biotin is part of the B vitamin family (it’s also known as vitamin B7). Since biotin is water soluble, it is not stored in the body, so excess biotin is excreted in urine. This helps lower the risk of toxicity, but also means you need to be replenishing your levels with food and supplements. 

Biotin is naturally-occurring in:

  • Nuts and seeds
  • Organ meats (e.g. liver)
  • Egg yolk
  • Avocado
  • Bananas
  • Cauliflower
  • Mushrooms
  • Leafy greens
  • Cheese

Looking to build a hormone balancing diet that works for your body? Grab my free meal plan & recipe guide aimed at helping you get your hormones in check!

What can biotin do for you?

Biotin is probably best known for its benefits for healthy hair, skin, and nails. It is said to restore strength to brittle nails, encourage hair growth, and lead to younger-looking skin.

Biotin for hair loss

While there isn’t a ton of research to demonstrate that high dose biotin is an effective treatment for alopecia, hair loss. This may be because hair loss can be due to a combination of issues including, biotin deficiency, autoimmunity, hormone imbalance and more. Many people have used biotin to encourage healthy hair and as you’ll find, many people swear by it. 

Because biotin deficiency does cause hair loss, it is included in various “hair growth” masques and other products (just so you know, before you go shelling out on these “miracle products”, biotin is most useful when consumed. It is not absorbed well through the skin). 

Ever heard of keratin? It’s a protein that makes up our skin, hair, and nails. Biotin improves the architecture of keratin, so that’s one way it could help promote and support healthy hair growth. 

Biotin for brittle nails 

Since biotin improves the quality of keratin (the protein nails are made of), it is helpful in restoring strength and flexibility to brittle, soft nails. 

Research has shown that biotin supplementation can help people experiencing problems with their nail health. In this study, of 32 people, one group composed of eight people with brittle nails experienced a whopping 25% increase in the thickness of their nails. 

Other biotin benefits

May help diabetics

Research has shown that biotin can help lower blood sugar. It also helps support insulin, encouraging better blood sugar balance.

In diabetes there is a dysfunction with insulin with either lack of production or resistance at the cell so that insulin can’t be used. Biotin may help with the production of insulin and support the blood sugar lowering effects of this hormone.

In one small study it was shown that supplementation with 9 mg of biotin was associated with an average reduction in blood sugar by 45% within one month. There have been other studies to show less promising effects, which means we definitely need more research to understand the benefits of biotin in diabetes. 

Supports the adrenals and thyroid

Biotin aids in proper endocrine function. Biotin deficiency can result in dysfunction of both the adrenals and thyroid. 

Biotin supplementation has been shown to cause false elevations of thyroid hormones, while also leading to falsely lowered TSH on labs. What does this mean? It means that your labs may show that you are hyperthyroid when in fact, you are not. Biotin does not cause hyperthyroidism. Instead it impacts the accuracy of the labs. A doctor correlating your symptoms with your labs would understand that you are not hyperthyroid based on labs alone.

What’s the solution? It is recommended to discontinue biotin supplementation 72 hours prior to lab testing. 

May help Multiple Sclerosis 

Multiple Sclerosis (MS) is an autoimmune disease that causes the destruction of the myelin sheath. The myelin sheath is what covers nerves and enables them to function properly. It’s like the orange plastic material that coats and extension cord. Without it, the electrical current doesn’t go from point A to point B.

Because biotin helps with fatty acid synthesis or in other words, the creation of fat, it is believed to support the neurological system. The myelin sheath and much of your brain and spinal cord are dependent on healthy fats to function. 

In one multicenter, randomized, placebo-controlled trial there was significant clinical improvements in people with progressive MS who received 300 mg of biotin for 48 weeks. In patients given the placebo there were no significant improvements noted. 

In another nonrandomized, uncontrolled pilot study of 23 people with progressive MS, high doses of biotin (100–600 mg per day) led to clinical improvements in visual loss and partial limb paralysis.

While biotin therapy has shown great promise in MS, it is important to remember that many factors impact this disease and its progression. As such, it is important to partner with a root cause medical provider in order to make sure you’re addressing your individualized needs.  

What are the symptoms of a biotin deficiency?

Biotin is a very important vitamin, and it’s vital that we have adequate amounts in the body. Biotin deficiency initially presents with hair, skin and nail symptoms. Longer term deficiency then begins to manifest as neurological symptoms. While biotin deficiency is rare, because it is present in a variety of popular foods, it is still possible. 

Symptoms of Biotin Deficiency:

  • Hair loss (alopecia)
  • Conjunctivitis (red, inflamed eyes)
  • Skin rashes (similar to eczema)
  • Seborrheic dermatitis (dandruff)
  • Seizures
  • Depression
  • Fatigue
  • Weakness
  • Lethargy
  • Low muscle tone
  • Ataxia (lack of coordination)
  • Susceptible to bacterial and yeast infections

Rashes on the face

Biotin deficiency can result in rashes on the face and body, and even seborrheic dermatitis (also known as dandruff). The rashes often appear red and scaly. 

If you’re experiencing unexplained rashes, as your doctor if biotin supplementation should be considered.

Thinning of the hair

Many women with Polycystic Ovarian Syndrome (PCOS) report improvements in hair growth when supplementing with biotin. This may be due to the effect on both hair synthesis and biotin’s ability to support optimal blood sugar. Hair loss is common in women with PCOS, as is blood sugar dysregulation. In fact, insulin and blood sugar metabolism are the root cause of many women’s PCOS. You can read more about PCOS here.

Despite there not being much research on the efficacy of biotin as a miracle hair vitamin some claim, a lack of biotin can result in hair loss. If you are losing more hair than is normal for you, a biotin deficiency may be the cause. 

Research has shown that supplementing with biotin when experiencing a deficiency can encourage new hair growth. 

And remember, you need biotin to actually make hair, so be sure your diet is filled with biotin rich foods.

Depression or lack of interest

Depression doesn’t always show up with just a feeling of being sad. Depression can also look like fatigue, disinterest in activities that normally bring joy, social isolation, and lack of motivation.

If you do not get enough biotin in your diet and become deficient, it is possible to experience symptoms of depression, lethargy, and a general feeling of malaise. 

Often, these symptoms resolve with supplementation. Some people will need to be on a supplement for life, however. 


Conjunctivitis is commonly referred to as “pink eye.” The conjunctiva is a layer of tissue that covers the whites of your eyes. When inflamed it turns a red color, which is why it gets the name pink eye.  

While it can be due to infection, it may also be a sign of biotin deficiency. Conjunctivitis is typically only found in severe cases of biotin deficiency

Seborrheic Dermatitis

You may have heard of cradle cap, which is the term seborrheic dermatitis that babies get. But adults experience this too. 

Seborrheic dermatitis is one of the most common inflammatory skin conditions. It can show up on the scalp, face, inside your ears, on your eyebrows and for men, in their beard. It is classically a white to yellow scale that forms in areas of oil production. 

A study of 541 females showed that biotin deficiency could lead to seborrheic dermatitis, and supplementation could be helpful in alleviating the symptoms. 


At its core, a seizure is a sudden electrical disturbance in the brain that can cause uncontrollable movements, feelings and loss of consciousness.

Inadequate levels of biotin can lead to seizures. Additionally, anticonvulsant medications (used to treat seizures in people with epilepsy) can lead to biotin depletion, so supplementation may be necessary. 

Talk with your doctor if you are currently taking any medication to ensure you’re not at risk of a biotin deficiency due to medication depletions. 


Any nutrient that supports healthy blood sugar, adrenal function, and thyroid health can help energy. In the case of biotin, it does all of this, plus supports energy production within the cell. It is an important nutrient that enables the mitochondria (cellular energy machines) to do their job.

In a study conducted on mice, biotin deficiency led to fatigue. Interestingly, the brain and muscles did not indicate biotin deficiency, but the liver did. Once the mice were given biotin, their symptoms reversed. 


Lethargy is more than just lack of energy. It can also show up as apathy, lack of interest in fun activities, and feeling like you’re more lazy than your normal self. Lethargy is another neurological symptom associated with biotin deficiency. 

Muscle Weakness

Without biotin, the mitochondria and nervous system can’t function at their best. In severe deficiency this can result in muscle weakness. 

Infants with biotin deficiency may show signs of weak muscles

Low muscle tone

Muscle strength, as we just discussed, is when you activate your muscles. It is different from muscle tone.

Muscle tone is about tension in the muscle when it is at rest. Low tone means there is very little tension and your limbs may appear floppy. Low tone results in a lack of fine motor skills, inability to maintain posture, lack of endurance for both gross and fine motor activities, poor coordination, and difficulty standing still. If you find you constantly need to lean against a wall or use something to prop yourself up then you may have low muscle tone.

Low muscle tone is a symptom usually associated with babies. A baby with low muscle tone can appear ‘floppy’, and not be able to control his or head very well. 


Ataxia is a medical term used to describe the loss of control in movement. Inability to pick items up, slurred speech, stumbling, falling when trying to stand up or walk can all be signs of ataxia.   

Biotin-responsive basal ganglia disease (also called thiamin metabolism dysfunction syndrome-2) can cause ataxia, or a lack of coordination, in children. The symptoms usually begin to manifest around three or four years old.  

Susceptible to bacterial and yeast infections

Biotin deficiency can make an individual more susceptible to bacterial and yeast infections. 

Finding you can’t clear yeast infections, athlete's foot, fungal overgrowth on your toe or experiencing strange rashes that are related to yeast? Make sure your doctor is evaluating you for a biotin deficiency. 

Who is at risk of a biotin deficiency?

While biotin deficiency is very uncommon, certain groups of people are more prone to it than others. 

Risk of Biotin Deficiency is Higher:

  • Pregnancy
  • Breastfeeding
  • Alcoholism
  • Long-term antibiotic use
  • Certain medications like anticonvulsants and isotretinoin (retin A)
  • Celiac disease or conditions that impact nutrient absorption through the intestines
  • Congenital defects
  • Smokers
  • Consumption of raw egg whites for a long period of time*

*Interestingly, raw egg white contains avidin, a protein that binds biotin so your body can not access it. Cooking eggs whites denatures this protein and increases the bioavailability of biotin. 

Pregnant women

You may notice that most prenatal vitamins contain biotin. The B vitamins as a whole are very important in the development of a healthy fetus, so it is important for mama to get enough of them.

Biotin is involved in the rapid cell division that takes place early in pregnancy. Deficiency of biotin has been shown to be teratogenic (causes birth defects) in many species.

Some studies have shown that as pregnancy progresses, biotin levels decrease and are significantly lower in the third trimester. It has been estimated that a substantial portion of pregnant women are marginally biotin deficient, meaning it can impact baby, but mom doesn’t present with overt deficiency symptoms. Studies have shown that supplementation of 300 mcg daily helps minimize issues of deficiency after just two weeks. This is why you’ll find 300 mcg of biotin in my Prenatal Plus supplement

Additionally, women who are lactating need more biotin than the average person, because they have a higher biotin output. 


Breastfeeding is one of the most energetically demanding phases in a woman’s life. In fact, many nutrients have higher recommended intake levels for this reason. Biotin is no exception.

A study concluded that biotin metabolism is altered in lactating women, which suggested that a higher recommended intake may be necessary for women who are breastfeeding. 


So we all know smoking is a bad habit for a myriad of reasons. It has absolutely no benefits, and a LONG list of horrible side effects (e.g. lung damage, cancer, heart disease…I could go on, but you get the gist). One negative effect of smoking that you may be unaware of is the possibility of a biotin deficiency. 

Studies have shown that women who smoke metabolize biotin faster, which leads to a mild biotin deficiency. 

If you are a smoker (of anything) or exposed to secondhand smoke, you may want to consider biotin as part of a B vitamin complex.


Alcohol intake is associated with several nutrient deficiencies, including biotin. Chronic intake of alcohol can lead to a large reduction in plasma biotin levels

If you consume alcohol regularly, consider taking a multivitamin or prenatal to help safeguard against nutrient deficiencies. Of course, the ideal is to limit alcohol intake rather than simply trying to out supplement it. However, I am a firm believer in harm reduction in lieu of judgement while you work on the root cause of the behavior. 

Long-term antibiotic use

Those good gut bugs do a whole lot for our health, including making biotin. Therefore, anything that kills off these critters can drive a biotin deficiency.

Antibiotics destroy both harmful and beneficial bacteria in the gut. Therefore, long-term use will end up destroying biotin-producing bacteria, too. 

Certain medications like anticonvulsants and isotretinoin (retin A)

Anticonvulsants (like those used to treat seizures in people with epilepsy) and isotretinoin can deplete biotin, leading to inadequate biotin levels in the body. 

Can birth control cause a biotin deficiency?

While there are many vitamins, minerals and antioxidants that birth control can cause deficiencies in, biotin is not one of them.

Celiac disease or conditions that impact nutrient absorption through the intestines

Celiac disease is when your immune system attacks your gut in response to gluten exposure. It hinders your ability to digest and absorb nutrients. 

Malabsorption of nutrients is characteristic of Celiac disease. People with a compromised ability to absorb nutrients are at an increased risk for nutrient deficiencies, including biotin deficiency. 

Congenital defects

If during pregnancy a woman does not have enough biotin, there is a chance of congenital defects in her child (in some animals, maternal biotin deficiency has been known to cause cleft palate and skeletal abnormalities).  

In addition, there are inherited defects that can affect your biotin status. When in doubt, meet with your doctor to find out if this is true for you.

Dietary  causes of biotin deficiency

Certainly if you are not eating enough biotin rich foods you could develop a deficiency. But did you know that consumption of raw egg whites for a long period of time have also been associated with deficiency? Skip the raw egg white protein drinks and instead opt for eggs where the whites are solid.

Biotin Rich Foods

  1. Egg, cooked 13-25 mcg
  2. Liver 27-35 mcg
  3. Salmon 4-5 mcg
  4. Avocado 2-6 mcg
  5. Raspberries 0.2-2 mcg
  6. Cauliflower 0.2-4 mcg
  7. Yeast packet 1.4-14 mcg 
  8. Sunflower seeds 2.6 mcg

Biotin Supplements

Biotin is beneficial for immune function, blood sugar regulation, hormone balance, energy production, healthy moods, pregnancy and breastfeeding, and nervous system support. It is also used to build strong and healthy hair, skin and nails.

Biotin Dosage

The adequate intake for an adult is 30 mcg daily. Thirty micrograms is also considered adequate for pregnant women, whereas breastfeeding women adequate intake levels are set at 35 mcg. However, many experts feel that this is substantially lower than what a typical individual needs to feel optimal. 

There is no Recommended Daily Allowance (RDA) because there isn’t substantial research to support recommendations. 

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This formula provides the nutrients your body needs to produce energy at the cellular level, while also supporting adrenal and thyroid function. In addition, important nutrients like vitamin B6 are readily available for your body to build healthy hormones and neurotransmitters. 

B vitamins are essential for liver detoxification of your own natural hormones, xenoestrogens (estrogen mimicking chemicals) and environmental toxins.

This formula also includes a proprietary blend of active isomer naturally-occurring folates. TMG and choline are included to support methylation.

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This formula also contains high gamma tocopherol vitamin E, high levels of all the B vitamins, including a proprietary blend of active isomer naturally-occurring folates, and natural mixed carotenoids. 

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If you’re a woman who is no longer menstruating or have issues with iron metabolism, this multivitamin is the better choice when compared to Prenatal Plus. 

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This formula is the better choice for menstruating females as it provides iron, an important mineral that is lost with menstrual blood.

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Other B Vitamins 

Many of us take multivitamins, which typically include all the B vitamins (as well as other vital vitamins and minerals). Some of us may choose to take a Vitamin B Complex, which contains all the B vitamins. 

I usually do not recommend supplementing with just one type of B vitamin, because increasing one could lead to a decrease in another, and create an unpleasant ripple effect from there. However, if you are deficient in a certain vitamin (e.g. you have a biotin deficiency), your healthcare practitioner may put you on a supplement containing just that one nutrient.

The next time you pick up your multivitamin or B Complex, check to see if it has all the B vitamins:  

  • B1 – thiamin
  • B2 – riboflavin
  • B3 – niacin
  • B5 – pantothenic acid
  • B6 – pyridoxine
  • B7 – biotin
  • B12 – cyanocobalamin
  • Folate (not folic acid)

Biotin Benefits – Summary

Biotin (vitamin B7) is an essential nutrient, which is present in a well-balanced whole-foods diet. It is best known for encouraging hair growth, healthy skin, and strong nails. Lesser known benefits include better blood sugar regulation, energy production, muscle strength, and neurological support.

A biotin deficiency is quite rare, but is possible (especially in pregnant women and smokers). Biotin deficiency can cause a skin rash, thinning hair, and symptoms of depression. Supplementation typically resolves these symptoms. 

Biotin is usually present in multivitamins and Vitamin B Complexes. It is also present in a wide array of widely consumed foods such as avocados, nuts and seeds, and bananas. 

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About The Author

Dr. Jolene Brighten

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Dr. Jolene Brighten, NMD, is a women’s hormone expert and prominent leader in women’s medicine. As a licensed naturopathic physician who is board certified in naturopathic endocrinology, she takes an integrative approach in her clinical practice. A fierce patient advocate and completely dedicated to uncovering the root cause of hormonal imbalances, Dr. Brighten empowers women worldwide to take control of their health and their hormones. She is the best selling author of Beyond the Pill and Healing Your Body Naturally After Childbirth. Dr. Brighten is an international speaker, clinical educator, medical advisor within the tech community, and considered a leading authority on women’s health. She is a member of the MindBodyGreen Collective and a faculty member for the American Academy of Anti Aging Medicine. Her work has been featured in the New York Post, Forbes, Cosmopolitan, Huffington Post, Bustle, The Guardian, Sports Illustrated, Elle, and ABC News. Read more about me here.