Thursday, November 26, 2009

How long does it take 4 hair 2 grow when taking biotin? Please answer!!!!?

When does it start taking effect? I need to grow my hair longer before May or June, about 4 inches or so.....because I'm going out of the US for the first time and I want my hair to grow....



How long does it take 4 hair 2 grow when taking biotin? Please answer!!!!?

HAIR NORMALLY GROWS AT A RATE OF 5 INCHES/YEAR.



Biotin



TRADE NAMES



D-Biotin (Numerous manufacturers), Biotin Forte (Vitaline Corporation), Meribin (Mericon Industries).



DESCRIPTION



Biotin, a member of the B-vitamin family, is an essential nutrient in human nutrition. It is involved in the biosynthesis of fatty acids, gluconeogenesis, energy production, the metabolism of the branched-chain amino acids (L-leucine, L-isoleucine, L-valine) and the de novo synthesis of purine nucleotides. Recent research indicates that biotin plays a role in gene expression, both at the transcriptional and translational levels, and that it may also play a role in DNA replication.



Biotin is widely distributed in natural foodstuffs. However, the absolute amounts of biotin in foodstuffs is relatively low when compared with the other B vitamins. Some of the better food sources of biotin, are egg yolk, liver, kidney, pancreas, milk, soya and barley. Brewer's yeast or Saccharomyces cerevisiae (see Brewer's Yeast), which is used as a nutritional supplement, is one of the richest sources of biotin, as well as the other B vitamins. Royal jelly, also used as a nutritional supplement (see Royal Jelly), is another rich source of biotin. Mammals and many plant species are unable to synthesize biotin. Biotin is synthesized by bacteria, yeast and other fungi, algae and certain plant species. In fact, the microflora of the human large intestine appear to contribute to the biotin requirements of the body.



The first demonstration of biotin-deficiency in animals was observed in animals fed raw egg white. Rats fed egg white protein were found to develop dermatitis, hair loss and neuromuscular dysfunction. This syndrome was called egg white injury and was discovered to be caused by a glycoprotein found in egg white called avidin. It was subsequently found that egg white injury could be cured by a liver factor which was first called protective factor X and later determined to be biotin. Because biotin cured the skin disorder of egg white injury it was called vitamin H. H is for haut, the German word for skin. Avidin causes egg white injury because it binds very tightly to biotin, preventing its absorption. This is only true for native avidin, which is resistant to hydrolysis by proteolytic enzymes. When egg white is cooked, avidin is denatured and denatured avidin is digested by proteolytic enzymes.



Although clinical biotin deficiency in humans is rare, it does occur. Prolonged consumption of raw egg white, long-term total parenteral nutrition without biotin supplementation and malabsorption syndromes, such as short-gut syndrome, have resulted in biotin-deficiency states. The symptoms and signs of biotin-deficiency, include a generalized erythematous scaly skin eruption, alopecia, conjunctivitis and neurological abnormalities. The rash may be distributed around the eyes, nose, mouth, ears and perineal orifices. The facial appearance associated with the deficiency, with the rash around the eyes, nose and mouth along with an unusual distribution of facial fat, is called biotin deficiency facies. In biotin deficient infants, the neurological findings are hypotonia, lethargy and developmental delay. In adults, the neurological findings are lethargy, depression, hallucinations and paresthesias of the extremities. Marginal biotin status may occur under certain conditions, e.g., during the first trimester of pregnancy, and it is thought that this situation may be teratogenic. Functional biotin deficiency occurs in certain genetic disorders. These will be discussed below.



Biotin is the coenzyme for four carboxylases. Acetyl coenzyme A (CoA) carboxylase, found in both the mitochondria and cytosol, catalyzes the carboxylation of acetyl-CoA to malonyl-CoA. Malonyl-CoA is the immediate precursor of 14 of the 16 carbon atoms of the fatty acid palmitic acid. It is also the immediate precursor of all of the fatty acids up to palmitic acid. Further, the reaction catalyzed by acetyl-CoA carboxylase, a complex reaction, is the primary regulatory, or rate-limiting, step in the biosynthesis of fatty acids. Pyruvate carboxylase, which is located in the mitochondria, catalyzes the carboxylation of pyruvate to form oxaloacetate. Oxaloacetate can be metabolized in the tricarboxylic acid cycle or it can be converted to glucose in the liver and kidney and other tissues that are involved in gluconeogenesis. The formation of oxaloacetate from pyruvate is known as an anaplerotic reaction. Anaplerotic is from the Greek word anaplerosis, meaning filling up or restoration. The pyruvate carboxylate reaction is the principal reaction which replenishes tricarboxylic acid cycle intermediates. Methylcrotonyl-CoA carboxylase, also located in the mitochondria, is involved in the metabolism of L-leucine, while the mitochondrial enzyme propionyl-CoA carboxylase is involved in the metabolism of L-isoleucine and L-valine, as well as L-threonine and L-methionine.



All four of the carboxylase enzymes, which use bicarbonate as their one-carbon substrate, share a common biochemical mechanism. In all four carboxylases, biotin is covalently linked by an amide bond between the carboxyl group of the valeric side chain of biotin and an epsilon-amino group of a specific lysyl residue in the apocarboxylase. The enzyme that catalyzes the formation of the covalent bond is called holocarboxylase synthetase. Biotin is recycled by the enzyme biotinidase. Biotinidase, an hydrolase, functions to recycle biotin by cleaving biocytin (epsilon-N-biotinyl-L-lysine), or short-chain oligopeptides containing biotin-linked lysyl residues, products of the normal breakdown of the holocarboxylases, to free biotin. Biotinidase is also thought to play a critical role in the release of biotin from biotin-containing dietary proteins. Recently, biotinidase has been found to have biotinyl-transferase activity. All five classes of histones are selectively biotinylated via the biotinyl-transferase activity of biotinidase. It is thought that biotinylation of histones is involved in the regulation of gene transcription and may also play a role in the packaging of DNA. Interestingly, biotinylation is an important technique in molecular biology. Biotin can be covalently linked to both proteins and nucleic acids, and is used as a label in many molecular biology and biochemistry technologies.



Certain inborn errors of metabolism result in functional biotin deficiency. These disorders, include multiple carboxylase deficiency, holocarboxylase synthetase deficiency, biotinidase deficiency and propionic-CoA carboxylase deficiency. Those with these disorders require much greater cellular biotin levels than normal in order to activate these biotin-dependent enzymes. Biotinidase deficiency is the most common cause of late-onset multiple carboxylase deficiency. Features of late-onset multiple carboxylase deficiency, include skin rash, alopecia, seizures, hypotonia, ataxia, hearing loss, optic atrophy, developmental delay, immune deficiency and recurrent infections. Coma and death may occur if the disorder is not treated. The treatment is high-dose biotin, which results in pronounced, rapid clinical and biochemical improvement. Holocarboxylase deficiency is the most common form of multiple carboxylase deficiency in neonates. Features of neonatal multiple carboxylase deficiency, include lethargy, hypotonia, vomiting, alopecia, lactic acidosis, keratoconjunctivitis, perioral erosions and seizures. Again, the treatment is high-dose biotin, which may completely reverse the symptoms and signs of the disorder. There is a relatively high incidence or propionyl-CoA carboxylase deficiency among the Inuits of Greenland. Those with this deficiency may present early in life with a severe, often fatal metabolic acidosis, hyperglycinemia and hyperammonemia. The only known treatment for this disorder is high-dose biotin. All of the above inborn errors of metabolism are referred to as biotin-responsive disorders.



Biotin is a bicyclic compound. The tetrahydrothiophene ring contains sulfur and has a valeric acid side chain. The second ring contains a ureido group. Eight stereoisomers of biotin exist. However, only one is found naturally, and it is the only one that is enzymatically active. The natural stereoisomer of biotin is called d-(+)-biotin or just biotin. In addition to being known as vitamin H, biotin is also known as hexahydro-2-oxo-1H-thieno[3,4-d]imidazol... acid; cis-5-(hexahydro-2-oxo-1H-thieno[3,4-d]i... acid; cis -tetrahydro-2-oxothieno[3,4-d]imidazolin... acid; cis-hexahydro-2-oxo-1H-thieno[3,4]imidaz... acid; coenzyme R and bios IIb. Its molecular formula is C10H16N2O3S and its molecular weight is 244.31 daltons. Biocytin or epsilon-N-biotinyl-L-lysine is a naturally occurring complex of biotin which has approximately the same biochemical activity as biotin.



How long does it take 4 hair 2 grow when taking biotin? Please answer!!!!?

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