Vitamin B7 (Biotin) Benefits, Supplement Uses, Signs of Deficiency & Side Effects

Vitamin B7 is a B-complex vitamin family member commonly called biotin.

Like the other seven B-complex vitamins, biotin is needed for turning foods into energy. This vitamin also helps the body to break down and utilize proteins and fats.

Vitamin B7 is commonly associated with increasing energy levels, especially in conditions where fatigue is a problem. It is also used for strengthening hair and nails, protecting vision, supporting the nervous system and detoxifying the liver. [1]

The University of Maryland Medical Center (UMM) states that B-complex vitamins are water soluble meaning they do not mix well with lipids (fats). As such, they are not stored in fat cells in the human body.

Because vitamin B7 is not stored, it must be routinely consumed from food sources or by taking a dietary supplement to avoid a deficiency. [1]

Previously there has not been much clinical research completed concerning the effects of vitamin B7 in specific health conditions. However, this and other B-complex vitamins are now being researched in various areas of health.

This article will discuss how biotin works in the body, current research on common uses and health benefits, signs of deficiency, safety and side effects, and possible interactions.

Biotin

Vitamin B7

Skin Health

Hair & Nails

Energy

How It Works:

• Important for healthy hair, skin & nails
• Supports energy levels & metabolism
• Involved in fatty acid synthesis

Dosage:

Between 1,000 - 10,000 mcg per serving

Safety:

Rated Likely Safe

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How Does Vitamin B7 Work in the Body?

The Linus Pauling Institute (LPI) states that all living organisms need vitamin B7 to live but only certain plants, algae, molds, yeast, and bacteria can produce it endogenously.

According to the LPI, the majority of bacteria that live in the human small and large intestines can synthesize biotin.

The LPI reports that some scientists believe that the microflora in humans most likely make more than enough vitamin B7 to meet people’s biological requirements. [2]

However, it is not yet known if the biotin produced in the gut is released or whether it is absorbed by humans in meaningful amounts. [2]

Because biotin is a water-soluble vitamin that humans do not store in any significant amounts, we must consume it regularly to maintain adequate levels in the body. The NMCD states that about 50% of biotin intake is excreted via urine within 24 hours following ingestion.

The amounts of biotin needed by the body to avoid deficiency are very low and it is found in small amounts in numerous foods. As such, deficiency in this vitamin is very rare.

Because deficiency is so rare, governments in most countries do not set recommended daily amounts of this nutrient. However, there are certain stages of life where getting adequate Vitamin B7 intake is particularly important.

Biotin status is important for women during pregnancy because this vitamin is believed to facilitate normal embryonic growth.

In various mammalian species, Vitamin B7 deficiency is known to be teratogenic (disrupt normal embryonic development) and can result in serious birth defects or a miscarriage. [9]

Research is being conducted to determine if deficiency in humans causes similar teratogenic effects. It has been observed that approximately half of all pregnant women may have reduced biotin status, meaning they may be at risk of deficiency or may have suboptimal levels of this vitamin in the body. [9]

Vitamin B7 is important for numerous biochemical reactions in the human body. It is also useful because it transports carbon dioxide (CO2) away from cells.

Some researchers have proposed that vitamin B7 is stored in cellular mitochondria, but this has not been definitively demonstrated.

Biotin is required to produce numerous enzymes that involve processes including glucose production (gluconeogenesis), metabolism of propionates, leucine catabolism (breakdown), and fatty acid synthesis.

In those diagnosed with diabetes mellitus as well as in unaffected healthy adults, increased biotin levels are associated with reduced blood glucose levels. The effect is much more pronounced in those with diabetes than in those without it. [3]

Vitamin B7 Uses and Health Benefits

The Natural Medicines Comprehensive Database reports that people use vitamin B7 supplements for a number of different purposes. Some common uses of biotin include: [3]

• Biotin deficiency
• Brittle nails
• Depression
• Diabetes
• Diabetic neuropathy
• Dialysis-related muscle cramps
• Hair loss
• Hair, skin, and nail health
• Infant seborrheic dermatitis
• Multiple sclerosis

Dr. Josh Axe states that vitamin B7 offers several important health benefits. According to Dr. Axe, biotin:

• Enhances muscle and tissue repair
• Maintains healthy skin, nails, and hair
• May help to balance blood glucose levels
• Supports a healthy cardiovascular system
• Supports brain structures and cognitive function
• Supports healthy metabolic function
• Supports proper thyroid and adrenal function [4]

The NMCD rates vitamin B7 as Likely Effective for preventing and treating biotin deficiency.

Some preliminary clinical trials using vitamin B7 for alopecia areata (hair loss), brittle nails, diabetes, diabetic neuropathy, dialysis-related muscle cramps, and multiple sclerosis have shown positive effects.

More research is needed to determine the therapeutic efficacy of vitamin B7 for these and other potential uses.

Some biotin formulations are categorized by the FDA as over-the-counter drugs. All other formulations are available as dietary supplements and are not intended prevent or treat any medical conditions.

Hair, Nail, and Skin Health

Vitamin B7 is commonly associated with improving the growth of hair, skin, and nails. It is frequently combined with Vitamin E and Vitamin C to improve keratin infrastructure.

Dr. Axe states that vitamin B7 is necessary for maintaining skin, hair, and nail health. [4] When people are chronically deficient in B7, they are likely to develop brittle/splitting hair, dry skin, and thinning hair.

Biotin is a common ingredient in numerous skin creams, shampoos, hair masques, and other products designed and marketed to enhance beauty. However, Dr. Axe says that B7 may be more effective when consumed orally than when it is applied topically.

More than one study has concluded that biotin can be helpful for strengthening weak nails and hair. It was first thought to be useful for these purposes when horses with dry, brittle hooves benefited from its application. [6]

Vitamin B7 is also purported to benefit skin cracking, rashes, dry skin, fungal infections and acne. However, more research is needed to rate its clinical efficacy in these conditions.

Some people believe that vitamin B7 is helpful for preventing or reversing alopecia (hair loss). It is sometimes recommended to men to help prevent balding and promote hair re-growth.

While oral biotin together with zinc aspartate and topical clobetasol has been seen to reverse alopecia areata (hair loss) in children caused by an anticonvulsant drug, there have been no similar studies done in adults, or in other cases of alopecia.

According to the LPI, “although hair loss is a symptom of severe biotin deficiency, there are no published scientific studies that support the claim that high-dose biotin supplements are effective in preventing or treating hair loss in men or women.” [2]

More research is needed to determine if vitamin B7 has positive effects on hair loss or premature balding.

Brain Function and Cognitive Decline

Vitamin B7 has roles in nerve signaling and influences the activities of neurotransmitters like Serotonin. Slight alterations in the function of neurotransmitters can cause significant changes in mood, energy, concentration, and memory.

Some researchers believe that vitamin B7 might be helpful for maintaining normal neurological function as we age. Along with other B-complex vitamins, it has been studied for the treatment of some diseases associated with cognitive decline, including Alzheimer’s disease and dementia.

Dr. Axe says that B-complex vitamins might act synergistically to defend the brain against forms of mild cognitive impairment common with aging. [4]

Currently, there have been no clinical studies conducted using vitamin B7 for cognitive function or neurological disorders. Human research will need to be completed to determine whether there is a connection between biotin use and cognitive function.

Thyroid/Adrenal Function

Together, adrenal and thyroid glands are responsible for regulating many physiological processes. Some of these include energy metabolism, sleep, hunger, pain, energy, and mood.

It is hypothesized that Vitamin B7 may help protect against adrenal fatigue and support the normal function of the thyroid gland. B7 deficiency has been linked to complications in both the adrenals and the thyroid.

Low B7 levels might result in weight gain, weight loss, fatigue, insomnia and irritability among other symptoms commonly seen with thyroid and adrenal gland issues.

There has not been any research in humans conducted to determine how this vitamin affects thyroid or adrenal function. Research is needed to determine therapeutic efficacy of biotin for this purpose.

Cardiovascular Health

Dr. Axe claims that vitamin B7 is important for helping to maintain a healthy cardiovascular system.

Like other B-complex vitamins, biotin may support the body’s normal defense against some of the most common causes for heart disease and blood vessel disease including chronic inflammation and the formation of arterial plaque. [4]

One study found that biotin significantly reduced triglyceride levels compared to a placebo in type 2 diabetic patients and non-diabetic patients with hypertriglyceridemia (elevated triglyceride levels). [10]

Another study found that biotin together with chromium picolinate significantly reduced triglyceride levels and improved the ratio of low-density lipoprotein cholesterol (LDL-C, “bad cholesterol”) to high-density lipoprotein cholesterol (HDL-C, “good cholesterol”) compared to placebo in moderately obese patients with type 2 diabetes. [5]

To date, there have not been any large, randomized studies using vitamin B7 for improving cardiovascular health in general populations. More research is needed to determine the therapeutic efficacy of biotin for cardiovascular health and disease.

Diabetes and Related Conditions

According to at least three separate studies, biotin may improve blood sugar regulation in people with diabetes.

Based on one published journal article, “Preliminary clinical research shows that a taking a specific supplement containing a combination of biotin 2 mg and chromium 600 mcg as chromium picolinate (Diachrome, Nutrition 21) can lower blood glucose and hemoglobin A1C levels in patients with type 2 diabetes who are poorly controlled on oral hypoglycemic drugs.” [3]

However, other preliminary data suggests that biotin alone has no effects on blood glucose or insulin sensitivity in patients with type 2 diabetes. More research is needed in this area.

Still other preliminary studies suggest that vitamin B7 can improve diabetic neuropathy symptoms when administered either orally or via injection.

One preliminary study found that intramuscular injections of 10 mg biotin once per day or three times weekly or 5 mg orally per day improves peripheral neuropathy associated with diabetes, including symptoms of muscle cramps, restless leg syndrome, paresthesia (tingling, “pins and needles” sensation), and the ability to walk and/or stand.

More research is needed to determine whether vitamin B7 can be used in clinical settings to improve blood glucose regulation, insulin sensitivity, glucose intolerance, or any other factors associated with diabetes mellitus.

Tissue Repair

Dr. Andrew Weil states that vitamin B7 is important for the maintenance and growth of muscles and other tissues. He says biotin works to rebuild strength in damaged muscles.

Dr. Weil asserts that vitamin B7 helps to reduce inflammation that can cause aches and pains in muscles. This vitamin might help to improve mobility and pain in people with arthritis and other conditions that cause muscle and/or bone pains. [6]

Low vitamin B7 levels can also contribute to stunted growth or otherwise abnormal development in infants and fetuses. This is the reason pregnant and nursing women are advised to consume more of this vitamin than all other groups.

Research is still needed to determine specific effects biotin supplementation may have on the maintenance of body tissues.

Vitamin B7 Deficiency

Vitamin B7 deficiency is rare. Humans only need small amounts of this vitamin each day to meet basic physiological needs and it is found in numerous foods. The body is also able to recycle some of the biotin it has already used.

Under certain circumstances, deficiency can develop, and some groups may be more at risk of becoming deficient than others. Dr. Weil says that the following factors can lead to a B7 deficiency: [6]

• Eating raw egg whites on a regular basis
• Intestinal malabsorption
• Intravenous feeding
• Long-term use of certain anti-seizure medications
• Prolonged oral antibiotic use

Raw egg whites contain avidin, a protein that can bind to vitamin B7 and hinder its absorption. Excessive consumption of raw egg whites can lead to a deficiency.

Dr. Weil states that deficiency of B7 can cause symptoms including dry skin, brittle hair and nails, intestinal tract problems, nervous system problems, muscle pain, and/or seborrheic dermatitis.

Vitamin B7 Foods

Many foods contain at least small amounts of vitamin B7. It frequently occurs together with other B-complex vitamins in both plant and animal sources.

According to the LPI, “Biotin can be found in brewer’s yeast; cooked eggs, especially egg yolk; sardines; nuts (almonds, peanuts, pecans, walnuts) and nut butters; soybeans; other legumes (beans, blackeye peas); whole grains; cauliflower; bananas; and mushrooms.” [2]

Cooking degrades biotin content in foods. Dr. Weil advises eating organic produce and raw and unprocessed food sources to maximize absorption of biotin content when possible.

Vitamin B7 Supplements

Vitamin B7 supplements are commonly available in 1000 microgram (mcg), 5000 mcg, and 10000 mcg preparations as well as being part of B-complex multivitamins and general multivitamins.

These supplements can be purchased in the form of oral tablets, capsules, soft gels, liquid drops, bulk powders, or as chewable gummies. There are rapid absorption tablets as well as products made with organic extra virgin coconut oil, which are purported to be more bioavailable in the body.

B-complex vitamins are known to compliment one another’s biological effects. Many doctors advise taking B vitamins only as part of a multivitamin that contains all B-complex family members.

Dr. Axe and Dr. Weil state that imbalanced B-complex status can result in various, serious symptoms. [4, 6]

They advise using only full-spectrum B-complex supplements except for in specific cases where a single B supplement may be of benefit. It is recommended to only supplement like this under the direction of a doctor.

Remember that not all dietary supplements are equally effective or manufactured with the same quality standards. Only purchase B7 supplements that have been manufactured under cGMP guidelines and are third-party tested to determine purity and quality.

Vitamin B7 Dosages

The LPI states that oral doses of vitamin B7 up to 200 mg/day have been used without adverse effects. However, the generally accepted dietary intake recommendations are much lower.

The following recommendations are reported by the National Academy of Sciences:

• 5 mcg daily for infants between 0 and 6 months of age
• 6 mcg/day for infants between 7 and 12 months
• 8 mcg/day for children between 1 and 3 years
• 12 mcg/day for children between 4 and 8 years
• 20 mcg/day for children between 9 and 13 years
• 25 mcg/day for children between 14 and 18 years
• 30 mcg/day for men and women 19 years and older
• 30 mcg/day for women during pregnancy
• 35 mcg/day for women when breastfeeding [2]

As a dietary supplement, this ingredient is typically taken in dosages of between 1000 mcg to 10000 mcg per day.

According to the Natural Medicines Comprehensive Database (NMCD), “In human research, single pharmacologic doses that are 600 times the normal dietary intake have been administered orally.”

The NMCD notes that dosages as high as 2.5 mg of biotin have been used in research studies to treat brittle nail syndrome. This dosage should only be used under medical supervision.

You should discuss the recommended dosage of biotin supplementation with a qualified physician before taking this product.

Vitamin B7 Side Effects and Interactions

According to the NMCD, Vitamin B7 supplements are rated Likely Safe when used orally and appropriately. It is generally well tolerated and has not caused adverse effects even when taken at dosages 600 times greater than the normal dietary intake.

Doses between 100 and 300 mcg daily of a highly concentrated biotin formulation have been used over several months without causing adverse effects. In one research trial, a single case of urticaria was reported.

Because of the apparent lack of side effects, the US Food and Drug Administration has not set an UL (upper tolerable limit) for vitamin B7.

Although side effects are rare with B7 supplement usage, there are various possible interactions with certain medications, herbs, lab tests and health conditions.

Cytochrome P450 Substrates

The NMCD states that biotin has may decrease the level of drugs metabolized by the cytochrome P450 substrate.

According to research from Baylor University Medical Center (BMC), the P450 cytochrome system utilizes a family of special enzymes (called isozymes) that affect the biotransformation of various pharmaceutical drugs.

BMC scientists say that “Drug metabolism via the cytochrome P450 system has emerged as an important determinant in the occurrence of several drug interactions that can result in drug toxicities, reduced pharmacological effect, and adverse drug reactions.” [7]

Researchers from Eastern Virginia Medical School state that statins, antidepressants, antiepileptics, and warfarin often interact with cytochrome P450 enzymes.

According to these researchers, “Cytochrome P450 enzymes are essential for the metabolism of many medications. Although this class has more than 50 enzymes, six of them metabolize 90 percent of drugs.” [8]

Ask your doctor if the medications you use are metabolized by the P450 cytochrome system, and how vitamin B7 supplements might affect their metabolism.

Antiseizure Medications

The University of Maryland Medical Center states that long-term use of antiseizure (antiepileptic) medications can lower biotin levels. Often, these drugs contain valproic acid which can cause a deficiency in an enzyme called biotinidase that enables the body to recycle used biotin.

Some of the most commonly used antiseizure medications are Carbatrol (carbamazepine), Dilantin (phenytoin), Mysoline (primidone), and phenobarbital.

In one study, subjects that routinely used anticonvulsant medications had 50% lower biotin plasma levels than subjects who did not use them. [3]

Although it is not evident if vitamin B7 contributes to seizures or not, you should discuss the use of a biotin supplement with your doctor before using it along with antiseizure drugs.

Other Drug Interactions

Biotin absorption may be hindered by both beta-carotene (vitamin A) and pantothenic acid (vitamin B5).

Seek medical advice about taking a vitamin B7 supplement if you smoke tobacco products or if you are receiving renal dialysis.

The NMCD states that vitamin B7 can cause inaccurate results on laboratory tests that measure levels of FT4 (free thyroxine) and TSH (thyroid stimulating hormone).

Like all B-complex vitamins, Vitamin B7 is required in the human diet. Speak with your doctor if you are interested in taking a biotin supplement to determine whether this product is appropriate for you.

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