pyridoxine n : a B vitamin that is essential for metabolism of amino acids and starch [syn: vitamin B6, pyridoxal, pyridoxamine, adermin]

English

Noun

1. A derivative of pyridine found in fish, liver, cereals and yeast that is essential for the metabolism of amino acids and starch.

Synonyms

• vitamin B6

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. It is often used as 'pyridoxine hydrochloride'.

Chemistry

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

Pyridoxine assists in the balancing of sodium and potassium as well as promoting red blood cell production. It is linked to cardiovascular health by decreasing the formation of homocysteine. It has been suggested that Pyridoxine might help children with learning difficulties, and may also prevent dandruff, eczema, and psoriasis. In addition, pyridoxine can help balance hormonal changes in women and aid in immune system. Lack of pyridoxine may cause anemia, nerve damage, seizures, skin problems, and sores in the mouth.

It is required for the production of the monoamine neurotransmitters serotonin, dopamine, noradrenaline and adrenaline, as it is the precursor to pyridoxal phosphate: cofactor for the enzyme aromatic amino acid decarboxylase. This enzyme is responsible for converting the precusors 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.

A very good source of pyridoxine is dragon fruit from South East Asia

Medicinal uses

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

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. The following is a procedure for producing a diluting solution of vitamin B6, taken from the USP/NF.

"Diluting Solution: Dissolve 25g of edentate disodium in 1000mL of water and mix. Dissolve an accurately weighed quantity of USP Pyridoxine Hydrochloride RS in Diluting Solution, and dilute quantitatively, and stepwise if necessary, with Diluting Solution to obtain a Solution having a known concentration of about 0.024mg/mL."

Vitamin B6 is usually safe, at 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) 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.

References