What is biotin?
Biotin is also called vitamin H or vitamin B8.
Biotin is unstable under the influence of oxygen gas and UV light.
Description of function
Biotin in humans plays an important role in the fat and sugar metabolism and the production of fatty acids. Biotin is necessary for the absorption of vitamin C from the viscera.
Biotin is a coenzyme-properties that allow to put the proteins and carbohydrates into energy and to participate in the production of prostaglandins from essential fatty acids.
Biotin is the co-factor (prosthetic group) of the enzymes carboxylases (specifically: carboxytransferasen). The action of this enzyme ensures that carbon dioxide is fixed in the organism.
Other important fields of application of biotin are growth and repair processes of the skin, the hair, the nails, the nerves and the bone marrow. For this reason it is often used in hair loss and hair growth problems. It is sometimes used in shampoos, but the effect is doubtful, because biotin is not absorbed by the skin.
To prevent
Although animals lack the ability to produce biotin, it is sometimes created by micro-organisms and plants. As a result, it comes in many different foods, but in general in low concentrations. There are only a few foods that contain biotin in large quantities, such as royal jelly, and baker's yeast.
The best natural sources of biotin in the human diet are organ meats such as liver and kidney, as well as egg yolk and some vegetables. Liver contains from about 1 mg / kg biotin. Fruits, most vegetables and (muscle) meat are poor sources and contain only about 0.01 mg of biotin per kg.
As far as vegetables are legumes, soybeans, peanuts, sugar beet, tomato, lettuce and carrots good sources, even though the concentrations are also relatively low. Further oats and rice.
It should be noted that the biotin of food may vary. It is influenced by factors such as plant species, season and refining (in the case of cereals).
Bioavailability
The bioavailability of biotin varies greatly, but is on average less than 50%. In some grains, such as maize, the bioavailability is almost 100%, whereas in other grains, such as wheat, is not more than 5%.
Synthesis in the intestine
Intestinal Bacteria can Biotin, but the synthesis of this vitamin can be affected by antibiotics and other medications.
Deficiency
Biotin deficiency may occur when eating large amounts of raw egg as egg protein includes avidin, which binds to biotin, and blocking its absorption in the gut. Heating inactivates avidin, which upon consumption of boiled or fried eggs no longer a risk to biotin deficiency. Biotin binds to avidin and related proteins (streptavidin and neuravidine), with an affinity constant K of 1015 M-1.
A biotin deficiency manifests itself in skin disorders, hair loss, weak nails, anemia, depression, fatigue, muscle pain, elevated cholesterol, inflammation of the tongue, and tingling or numbness in arms and legs.