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Pyridoxine ball-and-stick.png
CAS number 65-23-6 YesY
58-56-0 (HCl)
PubChem 1054
ChemSpider 1025 YesY
DrugBank DB00165
KEGG D08454 YesY
ChEBI CHEBI:16709 YesY
ATC code A11HA02
Jmol-3D images Image 1
Molecular formula C8H11NO3
Molar mass 169.18 g mol−1
Melting point 159–162 °C
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 YesY (verify) (what is: YesY/N?)
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.

It is on the World Health Organization's List of Essential Medicines, a list of the most important medication needed in a basic health system.[2]

Medicinal uses[edit]

Pyridoxine is given to patients taking isoniazid (INH) to combat the toxic side effects of the drug. It is given to people on isoniazide to prevent peripheral neuropathy and CNS effects that are associated with the use of INH.

Pyridoxine deficiency can lead to sideroblastic anemia.

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. However, vitamin B6 can cause neurological disorders, such as loss of sensation in legs and imbalance, when taken in high doses 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.[3] One study reported that over a 6-month period or longer, 21% of women taking doses greater than 50 mg daily experienced neurological toxicity.[4] 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.[5] Its also used to treat a Vitamin B6 deficiency.


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.[6] Lack of pyridoxine may cause anemia, nerve damage, seizures, skin problems, and sores in the mouth.[7]

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 melatonin, and levodopa (L-DOPA) into dopamine, noradrenaline and adrenaline. As such it has been implicated in the treatment of depression and anxiety.[citation needed]

Natural sources[edit]

Fish, soybeans, avocado, lima beans, chicken, bananas, cauliflower, green peppers, potatoes, spinach, raisins, brewer's yeast, blackstrap molasses, liver, kidney, heart. [8]


  1. ^ Pyridoxine at Sigma-Aldrich
  2. ^ "WHO Model List of EssentialMedicines". World Health Organization. October 2013. Retrieved 22 April 2014. 
  3. ^ Vitamin B6 (pyridoxine) - sources, benefits, dosage, deficiency, overdose, toxicity[full citation needed]
  4. ^ Dalton, K.; Dalton, M. J. T. (1987). "Characteristics of pyridoxine overdose neuropathy syndrome". Acta Neurologica Scandinavica 76 (1): 8–11. doi:10.1111/j.1600-0404.1987.tb03536.x. PMID 3630649. 
  5. ^ Briggs GG, Freeman RK, Yaffe SJ. Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 8th edition. 2008. Published by: Lippincott Williams & Wilkins.
  6. ^ Kashanian, M.; Mazinani, R.; Jalalmanesh, S. (2007). "Pyridoxine (vitamin B6) therapy for premenstrual syndrome". International Journal of Gynecology & Obstetrics 96 (1): 43–4. doi:10.1016/j.ijgo.2006.09.014. PMID 17187801. 
  7. ^ Vitamin B1,[full citation needed]
  8. ^ New Choices in Natural Healing, Rodale Press 1995

External links[edit]