Contributes to Normal Energy-Yielding Metabolism.
Every cell in your body depends on a continuous supply of energy to function efficiently.
Biotin contributes to normal energy-yielding metabolism by helping the body metabolise carbohydrates, fats and proteins. This enables your body to make effective use of the nutrients obtained from food and supports the many processes required for everyday life.

Although biotin does not provide energy itself, it plays an essential role in helping your body release energy from the foods you eat.

Supports the Maintenance of Normal Hair

Healthy hair depends on many factors, including genetics, hormones, overall health and good nutrition.

Biotin contributes to the maintenance of normal hair, making it one of the nutrients commonly associated with healthy hair growth and appearance.

While biotin deficiency is uncommon, maintaining an adequate intake through a balanced diet supports normal hair health as part of an overall healthy lifestyle.

Supports the Maintenance of Normal Skin

Your skin provides a protective barrier between your body and the outside environment.
Biotin contributes to the maintenance of normal skin, supporting healthy skin as part of a balanced diet and healthy lifestyle.

Good skin health also depends on adequate hydration, sun protection, sufficient sleep and a varied diet rich in essential nutrients.

Supports the Maintenance of Normal Mucous Membranes

Biotin contributes to the maintenance of normal mucous membranes, including the tissues that line the mouth, digestive tract and respiratory passages.

Healthy mucous membranes help support the body's normal protective functions and overall wellbeing.

Contributes to the Normal Functioning of the Nervous System

The nervous system relies on a continuous supply of nutrients to function normally.
Biotin contributes to the normal functioning of the nervous system by supporting the metabolic processes that help nerve cells produce energy and perform their normal functions.

Maintaining an adequate intake of biotin forms part of a healthy diet that supports normal nervous system function throughout life.

Supports Normal Psychological Function

Vitamin B7 also contributes to normal psychological function, supporting the body's normal metabolic processes involved in brain function.

Together with the other B-complex vitamins, biotin helps support overall health and wellbeing through its role in normal metabolism.

Food Sources of Vitamin B7

Biotin occurs naturally in many animal and plant foods.

Good dietary sources include:

• Egg yolks (cooked)
• Liver
• Salmon
• Sardines
• Lean pork
• Almonds
• Walnuts
• Sunflower seeds
• Peanuts
• Sweet potatoes
• Mushrooms
• Spinach
• Broccoli
• Whole grains

Although biotin is found in many foods, eating a varied diet remains the best way to help meet your daily nutritional requirements.

Could You Be Low in Vitamin B7?

Biotin deficiency is uncommon in healthy individuals because the vitamin is widely available in many foods and small amounts are also produced by bacteria naturally present in the gut. However, deficiency may occur in certain circumstances, such as prolonged inadequate dietary intake, specific inherited metabolic disorders, or conditions that affect nutrient absorption.

Some medications and prolonged use of certain anticonvulsant medicines may also influence biotin status. In addition, regularly consuming large quantities of raw egg whites over an extended period may reduce biotin absorption due to the presence of a protein called avidin, which binds to biotin. Cooking egg whites deactivates avidin and eliminates this effect.

Possible signs associated with biotin deficiency may include:

• Thinning hair or hair loss
• Dry or scaly skin
• Brittle nails
• Fatigue
• Tingling sensations in the hands and feet
• Low mood or irritability

These symptoms are not unique to biotin deficiency and may have many possible causes. If they persist or are causing concern, it is advisable to consult a healthcare professional for an appropriate assessment.

Can You Have Too Much Vitamin B7?

Biotin obtained naturally from food is considered safe and is not associated with harmful effects.

Because it is a water-soluble vitamin, excess amounts are generally excreted in the urine, and no tolerable upper intake level has been established for healthy individuals.

However, high-dose biotin supplements deserve special consideration. Large supplemental doses can interfere with certain laboratory blood tests, including tests used to assess thyroid function and some cardiac biomarkers, potentially leading to inaccurate results.

If you are taking a biotin supplement, particularly at high doses, it is important to inform your doctor or the laboratory before having blood tests performed.

As with all supplements, biotin should be taken according to the manufacturer's directions or the advice of a healthcare professional.

Supporting Your Daily Vitamin B7 Intake

Meeting your daily biotin requirements is usually straightforward when you eat a balanced and varied diet.

Simple ways to include more biotin-rich foods in your meals include:

• Enjoying cooked eggs as part of a healthy breakfast.
• Including salmon or sardines in your weekly meal plan.
• Adding mushrooms and spinach to omelettes, pasta dishes or stir-fries.
• Snacking on a handful of unsalted almonds or walnuts.
• Choosing wholegrain breads and cereals where possible.
• Including sweet potatoes and broccoli as part of your evening meal.
• A varied eating pattern that includes lean proteins, vegetables, whole grains and healthy fats provides biotin alongside many other essential vitamins and minerals that support overall health.

Key Takeaways

• Vitamin B7, also known as biotin, is an essential water-soluble B vitamin.
• Biotin contributes to normal energy-yielding metabolism, helping the body convert carbohydrates, fats and proteins into usable energy.
• It contributes to the maintenance of normal hair, normal skin and normal mucous membranes. 
• Biotin also contributes to the normal functioning of the nervous system and normal psychological function.
• Good dietary sources include cooked eggs, salmon, liver, nuts, seeds, mushrooms, sweet potatoes and whole grains.
• Biotin deficiency is uncommon but may occur in specific medical or dietary circumstances.
• High-dose biotin supplements may interfere with certain laboratory blood tests, so healthcare professionals should be informed before testing.

Supporting Your Nutritional Wellbeing

Vitamin B7 may be best known for its role in supporting healthy hair and skin, but its contribution to overall health extends much further. By contributing to normal energy-yielding metabolism and supporting the maintenance of healthy skin, hair, mucous membranes and nervous system function, biotin helps your body perform many essential everyday functions.

For most people, a balanced diet that includes a variety of nutrient-rich foods provides sufficient biotin to meet daily needs. Combined with regular physical activity, adequate sleep and healthy lifestyle habits, good nutrition provides a strong foundation for long-term wellbeing.

Rather than focusing on a single nutrient, aim for a varied and balanced eating pattern that supplies the full range of vitamins and minerals your body needs to function at its best.

References

• National Academies of Sciences, Engineering, and Medicine (1998) Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin and Choline. Washington, DC: National Academies Press. Available at: https://www.ncbi.nlm.nih.gov/books/NBK114310/
• National Institutes of Health, Office of Dietary Supplements (2025) Biotin – Fact Sheet for Health Professionals. Available at: https://ods.od.nih.gov/factsheets/Biotin-HealthProfessional/
• NHS (2025) Vitamins and Minerals – Vitamin B. Available at: https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-b/
• World Health Organization (2020) Healthy Diet. Available at: https://www.who.int/news-room/fact-sheets/detail/healthy-diet