VITAMIN B6 PYRIDOXINE

Vitamin B 6 occurs in three interchangeable forms: pyridoxine, pyridoxamine, and pyridoxal.
The active form in most enzyme systems is pyridoxal-5-phosphate.
Vitamin B 6 acts mainly as a coenzyme in the decarboxylation and transamination of a number of amino acids.
It also plays a role in the conversion of linoleic to arachidonic acid and in adrenocortical function.
The primary dietary sources of pyridoxine are meat, whole-grain cereals, green leafy vegetables, and potatoes.
The daily physiologic requirement of pyridoxine is 1 mg.
Clinical deficiency of pyridoxine may occur due to inadequate dietary intake, usually in conjunction with other vitamin deficiencies.
Alcoholism can lead to pyridoxine deficiency. Pyridoxine deficiency may be induced by drugs that increase excretion or decrease activity of the coenzyme, chiefly isoniazid, hydralazine, phenelzine, cycloserine, and penicillimine.
Oral contraceptives may alter pyridoxine metabolism but rarely cause clinical symptoms of deficiency.
Deficiency : causes seborrhea-like changes of the face, scalp, neck, shoulders, buttocks, and perineum. angular stomatitis(angle of mouth gets inflammed and fissured), cheilosis, glossitis, conjunctivitis, and intertrigo.
constitutional symptoms include anorexia, nausea, and vomiting. some individuals develop neurologic disturbances that include hyperesthesia, ascending paresthesia, altered vibration and position sense, and hypoactive deep tendon reflexes. Normochromic, normocytic anemia, lymphopenia, and eosinophilia may be seen