Thiamine (B1)

Question 1

NAMES AND SOURCES

Answer 1

also called Aneurine / anti beri-beri factor
Sources - best source - aleurone layer of cereals (whole wheat flour and unpolished rice)
good source - yeast

Question 2

ROLE OF THIAMINE IN BODY ( COENZYMES )

Answer 2

acts as coenzymes for the given enzymes
1. Pyruvate dehydrogenase :- pyruvate → acteyl Coa
2.α-keto glutarate dehydrogenase :- α-KGA →succinyl Coa
above both are oxidative decarboxylations
3.Transketolase activity :- involved in carbohydrate metabolism in HMP shunt pathway

Question 3

DEFICIENCY MANIFESTATIONS
- types
- symptoms

Answer 3

Beri-beri
symptoms - anorexia , heaviness , weakness , dyspepsia
1. wet beri-beri ( cardiovascular beri-beri)
cardiovascular manifestations , edema of leg face trunk serous cavities , palpitation , breathelessness , distended veins , death (due to heart failure)
2. dry beri-beri :-
neurological manifestations , difficulty in walking , peripherial neuritis with sensory disturbances leads to complete paralysis
3. infantile beri-beri :- in infants born to mother with B1 def.
sleeplessness , breathelessness , convulsions…..
MANIFESTATED - horizontal ridges on nails

Question 4

WERNICKE-KORSAKOFF SYNDROME

Answer 4

seen in chronic alcoholics
symptoms as same of encephalopathy - opthalmoplagia , nystagmus , cerebellar ataxia + psychosis
seen only when nutritional status is severely affected

Question 5

POLYNEURITIS

Answer 5

seen in chronic alcoholics
can be bcs of pregnancy and old age also
alcohol intake
↓
malabsorption of thiamine from intestine
↓
thiamine deficiency
↓
accumulation of pyruvate and lactate
↓
LACTIC ACIDOSIS

Question 6

BIOCHEMICAL PARAMETRES OF B1 DEF.

Answer 6

↑ PYRUVATE LACTATE α-KGA
↓thiamine content
↓erythrocytic trans ketolase activity(earliest symptom)
estimation via - hplc

Question 7

RDA

Answer 7

adults:- 2-3mg/day
pregnancy lactation - 3mg/day