The micronutrient biotin belongs to the group of B vitamins. Since skin and hair benefit from an adequate supply, the terms «vitamin H» or «beauty vitamin» are colloquial. However, vitamin B7 can do much more: the micronutrient is involved in numerous genetic and physiological processes – for example in our nerve function.
As an enzyme component, biotin plays a key role in supplying the brain with energy. FITBOOK explains why biotin is indispensable and presents all the facts about its nutritional importance.
The function of biotin in the body
Vital Functions of Biotin
Although many consumers associate biotin with a «beauty elixir» for skin, hair and nails, the vitamin primarily has numerous vital functions: The micronutrient supports our organism at the genetic level by involving biotin in DNA synthesis and the transmission of genetic information . The same applies to biotin-dependent cell growth – including via protein synthesis.
In order to supply the brain and muscles with essential energy, biotin-containing enzymes also regulate the metabolism of macronutrients: The breakdown of essential amino acids, gluconeogenesis (construction of the energy source glucose) and fatty acid synthesis are subject to the effects of vitamin B7. Last but not least, biotin is needed for our nervous system and psychological functions.
Biotin as a «beauty vitamin» for skin and hair
It has been proven that a sufficient supply of biotin can have a positive effect on skin and hair. According to «Ärztezeitung», vitamin B7 in combination with zinc has a positive effect on the hair cycle and on the formation of new hair cells. In addition, the regeneration of hair roots is activated. In a placebo-controlled, randomized, double-blind study, a biotin-containing supplement was shown to significantly increase the number of hairs in thinning hair.1
Despite additional proven effects on the skin metabolism, some advertising statements about vitamin B7 in supplements correlate with the specifications of the EFSA (European Food Safety Authority). For example, while the slogan «biotin for healthy growth of hair and skin» is approved, claims such as «biotin for strong hair» have not been scientifically proven.
The consumer center also criticizes that the biotin requirement can be sufficiently covered by food. An additional, aesthetic benefit for skin and hair through supplements has not been proven.
Also interesting: 8 foods for beautiful and healthy skin
Biotin for strong nails
Since veterinary studies came to the conclusion that pharmacological doses of biotin lead to an improvement in hoof quality in horses, among other things, it is being discussed whether a vitamin B7 food supplement also makes sense in human medicine.2
There are certainly study results that show positive effects on the nail quality in humans – including the activated regeneration of the nail bed. Individuals with what is known as “onychoschisis” (split fingernails and toenails) and/or “onychorrhexis” (brittle, split nail plates) may also benefit from a biotin supplement.3,4,5
However, the consumer center criticizes that the advertised strengthening effects on nails are not based on sufficient clinical data and further study results are necessary.
What is the daily requirement of vitamin B7?
Since according to the «Ernahrungs-Umschau» there are no human studies that provide exact results on the age-specific recommended intake of vitamin B7, the information is reference values that are given as estimated values in micrograms.
The DGE (German Society for Nutrition) recommends a daily intake of 40 micrograms for adolescents from the age of 15 and for adults. While the estimated daily requirement for biotin increases throughout life, breastfeeding women have the highest requirement at 45 micrograms of vitamin B7 per day.
Estimates for adequate biotin intake
Group Recommended intake µg/day Babies 0 to 3 months4 4 to 12 months6 Children and adolescents 1 to 3 years20 4 to 6 years25 7 to 9 years25 10 to 12 years35 13 to 14 years35 Adults over 15 years40 Pregnant women40 Breastfeeding women45
Source: DGE
The EFSA (European Food Safety Authority) also recommends a daily intake of 40 micrograms of biotin per day for adults.
What Are the Symptoms of Biotin Deficiency?
A deficiency situation is extremely rare due to the numerous sources of vitamin B7. Accordingly, a biotin deficiency is considered unlikely from a nutritional point of view with a balanced diet.
In addition, the water-soluble vitamin can be effectively «reused» (recycled) by the body, according to «Ernahrungs-Umschau». However, some factors (see “Factors Contributing to Biotin Deficiency”) can cause vitamin B deficiency symptoms to occur.
In contrast to other micronutrients, it takes a comparatively long time before the first signs of insufficient biotin intake appear. According to the «Ernahrungs-Umschau», the characteristic symptoms of a biotin deficiency include dermatological complaints such as skin rashes: In addition to what is known as «seborrheic dermatitis» – an inflammatory skin disease associated with scaly, red skin – an undersupply of biotin can lead to conjunctivitis, among other things (conjunctivitis) and lead to hair loss.
In the further course, muscular pain, functional disorders of the nervous system and psychological complaints such as depressive moods are also observed. In addition, a lack of vitamin B7 is typically associated with reduced performance and gastrointestinal dysfunction.
Due to the key role of biotin in the transmission of genetic information and in cell growth, developmental disorders can occur in infants.
Symptoms of vitamin B7 deficiency
- exhaustion
- developmental disorders in infants
- anorexia (loss of appetite)
- depressions
- hair loss
- Corner cheilitis (torn corners of the mouth)
- skin rash
- Conjunctivitis (conjunctivitis)
- nausea
- Muscle aches
- dizziness
Factors that favor a biotin deficiency
While a vitamin B7 deficiency is almost impossible as part of a balanced diet, there are genetic factors that can lead to a biotin deficiency. This is possible with a congenital disorder of biotin utilization. The same applies to a permanently restrictive food intake – for example in the case of an extremely one-sided or strict diet.
According to the consumer center, there are other factors that can lead to a lack of vitamin B7: either through reduced intake or stimulated breakdown of biotin. In this context, an unhealthy lifestyle with high alcohol consumption and smoking is just as possible as special medication (eg taking so-called “anticonvulsants” to treat epileptics). In the context of artificial nutrition, a deficiency situation cannot be ruled out either.
Caution: According to the consumer advice center, a high-dose drug with vitamin B7 is necessary for the hereditary metabolic disease “multiple carboxylase deficiency (MCD), which is characterized by reduced activity of biotin-dependent enzymes.
Studies have also shown that regular and high consumption of raw chicken protein can induce a biotin deficiency, as this reduces the absorption of the micronutrient. This situation could arise, for example, in strength athletes who prepare daily shakes with raw eggs for muscle building.
According to the BfR (Federal Institute for Risk Assessment), pregnant women may also belong to the risk group for biotin deficiency.
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Foods that contain a lot of biotin
Biotin is found in numerous plant and animal foods. While whole grain cereals such as oatmeal, wheat germ and brown rice, mushrooms, spinach and tomatoes are available as vegan sources of biotin, vegetarians can also cover their needs with milk and dairy products such as quark and hen’s eggs.
For flexitarians or omnivores, fish such as herring and meat are available in addition to these purely plant-based or vegetarian foods. Offal is particularly rich in biotin, but as a detoxification organ, it should be consumed in moderate amounts at most: A possible contamination with toxins and the like cannot be ruled out.
Culinary tip: To get enough biotin from food, you can start the day with muesli made from oatmeal, wheat germ, orange fillets, milk and a nut topping, for example. While a rice pan with mushrooms, spinach, tofu and carrots is ideal for lunch, jacket potatoes with quark, fried eggs and a tomato salad are ideal for dinner.
Biotin rich foods
- oatmeal
- wheat germ
- unpeeled brown rice
- Chicken egg (especially egg yolk)*
- beef and pork
- Milk, Quark & Brie
- Herring & Cod
- mushrooms
- Spinach & Carrot
- tomato
- soybeans
- Beef kidney and pork liver
- poultry
- nuts
- potatoes
- oranges
- lettuce
* It is important that eggs are not eaten raw, as regular consumption of unheated eggs can promote biotin deficiency.
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When can a dietary supplement with vitamin B7 make sense?
While biotin supplementation is not necessary as part of a balanced, healthy diet, a dietary supplement – based on the factors that promote biotin deficiency – can be useful in consultation with a doctor.
Danger: In the case of alcohol abuse, tobacco consumption and a restrictive diet, a supplement could improve the vitamin B7 status, but this would be counterproductive in terms of a healthy lifestyle: a reduction in alcohol consumption, no smoking and a balanced diet with oatmeal, brown rice and Aim for biotin-rich vegetables and dairy products.
You should discuss with your doctor whether a dietary supplement makes sense during long-term medication, in the case of metabolic disorders or during pregnancy.
Also interesting: The right time to take dietary supplements
Symptoms and consequences of vitamin B7 overdose
According to the BfR, it seems unlikely that a high intake of biotin-rich foods is associated with health risks. So far it is even unclear whether…