Vitamin B7 is also known as biotin, coenzyme R and vitamin H.
It is one of the group of B vitamins (also known as the "vitamin B-comlex"). See also an overview of the main vitamins.
Functions of Vitamin B7:
The main functions of vitamin B7 include the following.
Concerning digestion and metabolic processes:
- Helps to break-down the accumulation of fatty acids in the body via metabolic processes - which is why vitamin B7 is sometimes said to support weight loss.
- Helps with the metabolism of amino acids
- Coenzyme in carboxylation reactions - for the three enzymes listed below (this information is useful to people who need to understand the chemical reactions within the body, i.e. specific details about metabolism). :
- pyruvate carboxylase in gluconeogenesis
(gluconeogenesis is a metabolic pathway that produces glucose from non-carbohydrate carbon substrates e.g. lactate, glycerol, and glucogenic amino acids)
- acetyl CoA carboxylase in fatty acid synthesis
- propionyl CoA carboxylase in β oxidation of odd-numbered fatty acids
- Coenzyme for branched-chain amino acid metabolism reactions
Also, more generally:
- Helps with the absorption of other B vitamins.
- Supports health of skin, hair and fingernails (e.g. to help overcome eczema).
- Immune function - there have been suggestions that sufficient vitamin B7 in the body helps to support immune function, especially against yeast infections e.g. thrush.
... and in some cases:
- *Supplementation is sometimes recommended for diabetics, i.e. people who have the medical condition diabetes.
- *It has been suggested that, due to its role in fat metabolism, vitamin B7 may help with weight loss in some cases - though not as a replacement for appropriate healthy eating and exercise.
*Note that it makes sense to consult an appropriate expert before using nutritional supplements or other medications to attempt to treat medical conditions.
Sources of Vitamin B7:
Many different types of foods include some vitamin B7, although often in only small amounts.
Examples of foods that contain reasonably high levels of vitamin B7 include:
- Brewer's yeast
- Nuts, many types e.g. peanuts, almond, walnuts
- Egg yolks i.e. the yellow part of hens' eggs
- Offal e.g. liver and kidney
- Some seeds e.g. sesame seeds
- Saskatoon berries (as used in pies, jam, wines, cider, beers and sugar-infused in cereals, trail mix and snack foods)
In common with some other B vitamins, vitamin B7 is depleted by certain antinutrients e.g. alcohol and some antibiotics and is also reduced by some food processing techniques including cooking. Although vitamin B7 is present in egg yolks its value is depleted by the presence of raw egg whites because they contain the protein avidin that prevents vitamin B7 (biotin) from being absorbed in the intestines - which are part of the human digestive system.
Vitamin B7 (also known as biotin) is included in most diets and can be produced within the body. It is produced in the body by intestinal bacteria. In many cases sufficient is produced within the body to meet the body's needs. However, deficiency is possible - either due to inability of the intestines to absorb biotin in order to make it available to the rest of the body, or due to failure to produce sufficient quantities e.g. due to lack of sufficient intestinal bacteria - possibly following long-term use of antibiotics.
Problems due to insufficient or too much Vitamin B7:
Signs of Deficiencies of Vitamin B7
Signs of Excessive Intake of Vitamin B7
Deficiency in people consuming a balanced diet is very rare.
However, deficiency of vitamin B7 can lead to:
Vitamin B7 is not generally considered toxic if consumed in excessive quantities.
- cradle cap (in infants)
- premature loss of hair colour (to grey, then white) and/or premature loss of hair (alopecia)
- "low" moods such as lethargy and depression
Possible causes of vitamin B7 deficiency include eating lots of raw egg whites (leading to inability to absorb vitamin B7) and long-term use of antibiotics.
See also vitamins, minerals, amino acids, what is a balanced diet? and the health benefits of drinking water.