Vitamin B6 (Pyridoxine) – Chemistry, Functions, Food Sources, Deficiency

Chemistry and Characteristics

Vitamin B6 consists of a group of related compounds: pyridoxine, pyridoxal and pyridoxamine. Vitamin B6 is soluble in water and relatively unstable to heat and to acids. It is destroyed in alkaline solutions and is also sensitive to light.

Functions

Vitamin B6 is the coenzyme for a large number of enzyme systems, most of which are involved in amino acid metabolism. It plays a role in the conversion of (a) tryptophan to niacin (b) linoleic to arachidonic acid and in the (c) interconversion of amino acids.

Food Sources

Foods rich in pyridoxine are meat, poultry and fish. Potatoes, sweet potatoes are fair sources. Whole grain cereals are also good sources.

Recommended Dietary Allowances

The recommended allowance of vitamin B6for adults is 2 mg/d.

Deficiency

The deficiency of this vitamin causes impaired protein synthesis and microcytic hypochromic anaemia (smaller sized RBCs pale in colour due to low concentration of haemoglobin). The symptoms include convulsions, dizziness, vomiting, cheilosis, glossitis and abdominal pain.