Vitamin B7

Vitamin B7, also known as biotin, is a water-soluble vitamin that belongs to the B-complex family. It plays a crucial role in various metabolic processes, including the synthesis of fatty acids, the metabolism of amino acids, and the conversion of glucose into energy. Additionally, vitamin B7 is essential for maintaining healthy skin, hair, and nails.


The discovery of vitamin B7 can be traced back to the early 20th century. In the 1920s, researchers observed that consuming raw egg whites led to a condition called “egg white injury” in rats. This condition was characterised by hair loss, dermatitis, and neurological symptoms. Later, in the 1930s, Hungarian researcher Paul György identified a factor in liver extract that could prevent this condition, which he named “vitamin H” (H stands for “Haut und Haar,” meaning “skin and hair” in German).

Functions Of Vitamin B7

Vitamin B7, or biotin, plays a vital role in various metabolic processes and other functions within the human body. Some of the key functions of vitamin B7 include:

  • Carbohydrate metabolism: Biotin acts as a coenzyme for several enzymes, known as carboxylases, which are involved in the metabolism of carbohydrates. It helps convert glucose into energy, which is essential for the proper functioning of cells and organs.
  • Fatty acid synthesis: Biotin is crucial in the process of synthesizing fatty acids. It assists in the production of essential fats that contribute to the maintenance of cell membranes and the regulation of inflammation and hormone production.
  • Amino acid metabolism: Vitamin B7 plays a role in the metabolism of amino acids, the building blocks of proteins. It is involved in the breakdown and utilization of amino acids for energy production and other biological processes.
  • Gluconeogenesis: Biotin participates in gluconeogenesis, a process by which the body generates glucose from non-carbohydrate sources, such as amino acids and glycerol. This is particularly important during periods of fasting or when carbohydrate intake is low.
  • Maintaining healthy skin, hair, and nails: Biotin is necessary for the production of keratin, a structural protein found in skin, hair, and nails. Adequate levels of biotin contribute to the maintenance of healthy skin, hair, and nails, and a deficiency can lead to various dermatological and hair issues.
  • Gene regulation: Biotin has been found to play a role in the regulation of gene expression, which is essential for various cellular functions, including growth, development, and responses to environmental changes.
  • Nervous system function: Vitamin B7 is involved in the synthesis of neurotransmitters, which are essential for proper brain function and communication within the nervous system. Biotin deficiency has been linked to neurological issues like cognitive impairment and depression.

Good Sources Of Vitamin B7

Vitamin B7, or biotin, is found in a variety of food sources. Incorporating these foods into your diet can help ensure you get adequate amounts of this essential nutrient. Some good sources of vitamin B7 include:

  • Egg yolks: Egg yolks are one of the richest sources of biotin. However, it is essential to cook the egg whites, as raw egg whites contain a protein called avidin, which can interfere with biotin absorption.
  • Nuts and seeds: Almonds, peanuts, walnuts, pecans, and sunflower seeds are good sources of biotin.
  • Legumes: Legumes like lentils, beans, and peas contain biotin and provide additional nutritional benefits like protein, fibre, and minerals.
  • Whole grains: Whole grains such as oats, barley, brown rice, and whole wheat products contain biotin and other essential nutrients.
  • Dairy products: Milk, cheese, and yogurt are sources of biotin, in addition to providing calcium, protein, and other essential nutrients.
  • Fish: Some fish, like salmon and sardines, are good sources of biotin and also provide heart-healthy omega-3 fatty acids.
  • Meat and poultry: Organ meats like liver and kidney are rich in biotin. Other meat sources, such as chicken and turkey, also contain biotin, though in smaller amounts.
  • Vegetables: Certain vegetables, including sweet potatoes, cauliflower, mushrooms, and spinach, provide biotin as well as other essential nutrients.
  • Fruits: While fruits are generally not as rich in biotin as other food groups, some fruits like avocado, raspberries, and bananas contain small amounts of the vitamin.

Keep in mind that biotin is water-soluble and sensitive to heat, so overcooking or overprocessing foods can decrease the biotin content. To maximise biotin intake, consume a balanced and varied diet that includes a wide range of these food sources.

How Much Vitamin B7 Do We Need?

The recommended daily intake of vitamin B7 (biotin) varies depending on age, sex, and life stage. The National Institutes of Health (NIH) provides the following Adequate Intakes (AI) for biotin:

  • Infants (0-6 months): 5 mcg/day (micrograms)
  • Infants (7-12 months): 6 mcg/day
  • Children (1-3 years): 8 mcg/day
  • Children (4-8 years): 12 mcg/day
  • Children (9-13 years): 20 mcg/day
  • Teens (14-18 years): 25 mcg/day
  • Adults (19 years and older): 30 mcg/day
  • Pregnant women: 30 mcg/day
  • Breastfeeding women: 35 mcg/day

These values are classified as the adequate intake (AI) not recommended dietary allowance (RDA).

It’s important to note that these are general guidelines, and individual needs may vary depending on factors such as overall health, lifestyle, and dietary choices. Most people can obtain adequate amounts of biotin through a balanced and varied diet that includes biotin-rich foods.

If you have concerns about your biotin intake or are considering taking supplements, it’s best to consult with a healthcare professional to determine the appropriate dosage for your specific needs.

What Are The Signs of Vitamin B7 Deficiency?

Biotin deficiency is rare, as the vitamin is widely available in a variety of food sources, including egg yolks, nuts, seeds, legumes, whole grains, and certain vegetables like cauliflower and mushrooms. Moreover, some bacteria in the human gut are capable of producing small amounts of biotin.

Symptoms: Biotin deficiency can lead to various symptoms, including:

  • Hair loss (alopecia)
  • Skin rashes or inflammation (dermatitis)
  • Brittle nails
  • Fatigue and muscle weakness
  • Neurological symptoms like depression, seizures, and cognitive impairment

What Happens If I Take Too Much Vitamin B7?

Vitamin B7, or biotin, is a water-soluble vitamin, which means that excess amounts are generally excreted through urine, reducing the risk of toxicity. As a result, there have been no reported cases of toxicity from consuming high levels of biotin from food sources or even from taking supplements at doses much higher than the recommended daily intake.

However, taking extremely high doses of biotin supplements may cause some issues:

  • Interference with lab tests: High levels of biotin in the bloodstream can interfere with certain laboratory tests, including those for thyroid hormones, cardiac troponin, and other hormone tests. This can lead to false results, which may cause misdiagnosis or inappropriate treatment.
  • Potential drug interactions: Biotin may interact with certain medications, such as anticonvulsants, which could reduce the effectiveness of the medications or affect the levels of biotin in your body. If you are taking any medications, consult with your healthcare provider before starting a biotin supplement.
  • Unknown long-term effects: While no immediate toxicity has been reported from high doses of biotin, the long-term effects of consuming excessive amounts are not well understood.
  • Imbalance of nutrients: Consuming very high amounts of one nutrient, even a water-soluble vitamin like biotin, can potentially create imbalances with other nutrients in the body.

It is generally best to obtain nutrients, including biotin, from a well-balanced and varied diet rather than relying on high-dose supplements. If you are considering taking biotin supplements, consult with a healthcare professional to determine the appropriate dosage based on your specific needs.