VITAMIN B7 (Biotin,
also known as vitamin H or coenzyme R)
Vitamin B7 is used in cell growth, the production of fatty acids and the metabolism of fats and proteins. It plays a role in the Krebs cycle, which takes place within the mitochondria. Biotin is also required for healthy hair and skin, healthy sweat glands, nerve tissue and bone marrow and assisting with muscle pain. Vitamin B7 not
only assists in various metabolic chemical conversions, but also helps with the transfer of carbon dioxide and is also helpful in maintaining a steady blood sugar level.
Biotin is used in the body to metabolise both sugar and fat. In metabolising sugar, biotin transports sugar from its beginning stages to its eventual conversion into usable energy. An enzyme called acetyl Coenzyme-A carboxylase requires biotin to function properly. This enzyme forms the building blocks of fat production in the body and is critical as all cell membranes in the body need to contain the correct fat components in order to function effectively
including those in the brain.
Other nutrients that are required for the effective use of vitamin B7 are chromium, magnesium, manganese and vitamins B2, B3, B5, B6, B9 and B12.
Deficiency of vitamin B7
The nervous system can be affected by a biotin deficiency. Symptoms can include seizures, lack of good muscle tone, lack of coordination and seizures. Muscle cramps related to physical exertion can also be a symptom, as the body will have an impaired system to effectively use sugar as fuel. Other symptoms can include:
Coffee has a mild diuretic effect, which increases urination and water soluble vitamins, such as the B vitamins, can be depleted as a result of this fluid loss. In addition, it also interferes with the metabolism of some B vitamins, such as vitamin B7. Prolonged diarrhoea, drinking excessive alcohol and liver disease impairs the body's ability to absorb vitamin B7. Athletes, dancers and others involve in extreme physical activities may become deficient in vitamin B7 due to excessive perspiration and fluid loss.
See Performers and Sports Nutrition
Highest sources of vitamin B7 in micrograms per 100 grams
Chicken livers 180 µg
Egg yolk 60 µg
Walnuts 39 µg
Oatmeal 35 µg
Peanuts 34 µg
Fish 20 µg
µg is equivalent to one microgram.
NOTE: There are high levels of a protein called avidin in raw egg whites which bind to vitamin B7 (biotin) which may cause a deficiency of this vitamin if consumed over a few months. When cooked, avidin is partially denatured and binding to biotin is reduced. However one study showed that 30-40% of the avidin activity was still present in the white after frying or boiling so consumption of cooked egg whites should be limited to about three times a week whereas egg yolks, that contain most of the nutrients and no avidin, should be consumed more often. The other alternative is to eat extra foods rich in vitamin B7 the same day as eating egg whites.