Biotin is one of the B vitamins. It is a water-soluble and sulfur-containing vitamin.
Biotin is necessary for the production and utilization of fats and amino acids in the body.
Mammals and many species of plants are unable to synthesize biotin; however, biotin is synthesized by bacteria, yeast, other fungi and algae, and by certain plant species.
Because bacteria synthesize biotin, the microflora of the large intestine contributes to the human body’s biotin requirements.
The amount of biotin found in foods is much lower when compared to other B vitamins.
Avidin found in raw egg white binds tightly to biotin, resulting in a decreased absorption. However, cooking inactivates avidin.
Biotin
is a cofactor for enzymes that are involved in the metabolism of carbohydrate,
fat, and protein. Enzymatic reactions involving biotin allow the transfer of
carbon dioxide, CO2, in biochemical reactions that are essential for
the metabolism of carbohydrates, fat, and protein.
As a coenzyme, biotin plays a role in the deamination, which generates energy from certain amino acids.
The four carboxylase enzymes in mammalian tissue that require biotin are: acetyl coenzyme A (CoA) carboxylase, pyruvate carboxylase, propionyl CoA carboxylase, and â-methylcrotonyl CoA carboxylase.
Biotin is involved in the formation of purines, an essential part of DNA and RNA.
Biotin may modulate gene expression at the transcriptonal and translational
concentrations.
Although clinical deficiency of biotin is rare, it can
occur from prolonged consumption of raw egg whites, which contains the
biotin-binding protein, avidin. Avidin is destroyed by cooking.
Deficiency can also occur from long-term total parenteral nutrition, a genetic
defect in the biotin-dependent enzymes, or from malabsorption syndromes such as
short-gut syndrome.
Some signs of biotin deficiency are:
dry, scaly skin
nausea
anorexia
seborrheic dermatitis
alopecia (hair loss)
conjunctivitis
neurological abnormalities
Note: These symptoms are also common to a deficiency in essential fatty acids.
No toxic effects of oral biotin have been reported in humans or animals, even at doses up to 10 mg/day. Biotin is found in multivitamin/mineral supplements which typically contain between 30 – 60 mcgs per daily dose.
Individuals with a carboxylase deficiency are usually treated with pharmacologic doses of biotin. A study showed that high oral doses of biotin were completely absorbed in healthy adults. 2
Anticonvulsants, such as carbamazepine and Phenobarbital, may deplete biotin by competing with
it for absorption in the intestine. Biotin supplementation may be helpful during long-term anticonvulsant therapy. Also, taking biotin supplements two to three hours apart from the drug prevents this potential interaction.
Information on the relationship between substances and disease is provided for general information, in order to convey a balanced review of the scientific literature. In many cases the relationship between a substance and a disease is tentative and additional research is needed to confirm such a relationship. 345
Nutrient Interaction: Biotin and lipoic acid have structural similarities. Rats were treated with different doses of lipoic acid with or without biotin for 28 days and hepatic enzyme activities were measured. As a result, activities of pyruvate carboxylase and â-methylcrotonyl-CoA were lowered by lipoic acid, but not by lipoic acid plus biotin. Since lipoic acid has gained popularity as a dietary supplement to treat diabetic neuropathy, caution should be taken. 6
Cytokine Release: Biotin was found to have a role in regulating the genetic expression of biotin-dependent carboxylase at the mRNA concentration in rats in a study. The results suggested that biotin acts as a modulator in the genetic expression of the enzymes involved in its function as a cofactor (i.e. holocarboxylase synthetase). 7 Another study investigated the effects of a pharmacological dose of biotin on cell proliferation in peripheral blood mononuclear cells (PBMC) and cytokine release in healthy adults. Healthy adults were given ~750 mcg/day of biotin for 14 days. Results showed that the pharmacological dose of biotin did not change the percentage of PBMC, but decreased synthesis of interleukin-1ß and interleukin-2.
8
The dietary supplement information contained on this site has been compiled from published sources thought to be reliable, but it cannot be guaranteed. Efforts have been made to assure this information is accurate and current. However, some of this information may be purported or outdated due to ongoing research or discoveries. The authors, editors and publishers cannot accept responsibility for errors or omissions or for any consequences from applications of the information in this site and make no warranty, expressed or implied, with respect to the contents herein.
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