Deficiency Vitamin B6

1 deficiency

1.1 signs , symptoms
1.2 diagnosis
1.3 causes

deficiency
signs , symptoms

the classic clinical syndrome vitamin b6 deficiency seborrhoeic dermatitis-like eruption, atrophic glossitis ulceration, angular cheilitis, conjunctivitis, intertrigo, , neurologic symptoms of somnolence, confusion, , neuropathy (due impaired sphingosine synthesis) , sideroblastic anemia (due impaired heme synthesis).

less severe cases present metabolic disease associated insufficient activities of coenzyme plp. prominent of lesions due impaired tryptophan–niacin conversion. can detected based on urinary excretion of xanthurenic acid after oral tryptophan load. vitamin b6 deficiency can result in impaired transsulfuration of methionine cysteine. plp-dependent transaminases , glycogen phosphorylase provide vitamin role in gluconeogenesis, deprivation of vitamin b6 results in impaired glucose tolerance.

diagnosis

the assessment of vitamin b6 status essential, clinical signs , symptoms in less severe cases not specific. 3 biochemical tests used activation coefficient erythrocyte enzyme aspartate aminotransferase, plasma plp concentrations, , urinary excretion of vitamin b6 degradation products, urinary pa. of these, plasma plp best single measure, because reflects tissue stores. plasma plp less 10 nmol/l indicative of vitamin b6 deficiency. plp concentration greater 20 nmol/l has been chosen level of adequacy establishing estimated average requirements , recommended daily allowances in usa. urinary pa indicator of vitamin b6 deficiency; levels of less 3.0 mmol/day suggestive of vitamin b6 deficiency.

the classic syndrome vitamin b6 deficiency rare, in developing countries. handful of cases seen between 1952 , 1953, particularly in united states, , occurred in small percentage of infants fed formula lacking in pyridoxine.

causes

a deficiency of vitamin b6 alone relatively uncommon , occurs in association other vitamins of b complex. elderly , alcoholics have increased risk of vitamin b6 deficiency, other micronutrient deficiencies. evidence exists decreased levels of vitamin b6 in women type 1 diabetes , in patients systemic inflammation, liver disease, rheumatoid arthritis, , infected hiv. use of oral contraceptives , treatment anticonvulsants, isoniazid, cycloserine, penicillamine, , hydrocortisone negatively impact vitamin b6 status. hemodialysis reduces vitamin b6 plasma levels.