Pyridoxine

Pyridoxine[1]
IUPAC name 4,5-Bis(hydroxymethyl)-2-methylpyridin-3-ol
Identifiers
CAS number	65-23-6 Y,  58-56-0 (HCl)
PubChem	1054
ChemSpider	1025 Y
DrugBank	DB00165
KEGG	D08454 Y
ChEBI	CHEBI:16709 Y
ChEMBL	CHEMBL1364 Y
ATC code	A11HA02
Jmol-3D images	Image 1
SMILES CC1=NC=C(C(=C1O)CO)CO
InChI InChI=1S/C8H11NO3/c1-5-8(12)7(4-11)6(3-10)2-9-5/h2,10-12H,3-4H2,1H3 Y Key: LXNHXLLTXMVWPM-UHFFFAOYSA-N Y
Properties
Molecular formula	C8H11NO3
Molar mass	169.18 g mol−1
Melting point	159-162 °C
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Pyridoxine is one of the compounds that can be called vitamin B₆, along with pyridoxal and pyridoxamine. It differs from pyridoxamine by the substituent at the '4' position. Its hydrochloride salt pyridoxine hydrochloride is often used.

Chemistry[edit]

It is based on a pyridine ring, with hydroxyl, methyl, and hydroxymethyl substituents. It is converted to the biologically active form pyridoxal 5-phosphate.

Function in the body[edit]

Vitamin B₆ assists in the balancing of sodium and potassium as well as promoting red blood cell production.^{[citation needed]} It is linked to cardiovascular health by decreasing the formation of homocysteine. Pyridoxine may help balance hormonal changes in women and aid the immune system.^[2] Lack of pyridoxine may cause anemia, nerve damage, seizures, skin problems, and sores in the mouth.^[3]

It is required for the production of the monoamine neurotransmitters serotonin, dopamine, norepinephrine and epinephrine, as it is the precursor to pyridoxal phosphate: cofactor for the enzyme aromatic amino acid decarboxylase. This enzyme is responsible for converting the precursors 5-hydroxytryptophan (5-HTP) into serotonin and levodopa (L-DOPA) into dopamine, noradrenaline and adrenaline. As such it has been implicated in the treatment of depression and anxiety.^{[citation needed]}

Very good sources of pyridoxine are grains and nuts.^{[citation needed]}

Medicinal uses[edit]

Pyridoxine is given to patients taking isoniazid to combat the toxic side effects of the drug. It is given 10–50 mg/day to patients on to prevent peripheral neuropathy and CNS effects that are associated with the use of INH.

It is also essential for patients with extremely rare pyridoxine-dependent epilepsy, thought to be caused by mutations in the ALDH7A1 gene.

In one form of homocystinuria, activity of the deficient enzyme can be enhanced by the administration of large doses of pyridoxine (100-1000 mg/day).

Vitamin B₆ can be compounded into a variety of different dosage forms. It can be used orally as a tablet, capsule, or solution. It can also be used as a nasal spray or for injection when in its solution form.

Vitamin B₆ is usually safe, at regular intakes up to 200 mg per day in adults. However, vitamin B₆ can cause neurological disorders, such as loss of sensation in legs and imbalance, when taken in high doses (200 mg or more per day - 10,000% of US RDA) over a long period of time. Vitamin B₆ toxicity can damage sensory nerves, leading to numbness in the hands and feet as well as difficulty walking. Symptoms of a pyridoxine overdose may include poor coordination, staggering, numbness, decreased sensation to touch, temperature, and vibration, and tiredness for up to six months.^[4] One study reported that over a 6 month period or longer, 21% of women taking doses greater than 50 mg daily experienced neurological toxicity.^[5] The effect of doses below 50 mg was not reported. Pyridoxine's fetal safety is "A" in Briggs' Reference Guide to Fetal and Neonatal Risk.^[6] Its also used to treat a Vitamin B6 deficiency.

References[edit]