Thiamine

Question 1

Vitamin _____

_____ soluble

Food sources

Y
O
L
B
W
N

Answer 1

B1

water

yeast, organ meat, legumes, beef, whole grains, nuts

Question 2

Absorbed in

Functions as coenzyme in

important in enzymes such as

greatest need for thiamine in

deficiency results in

impairment leads to severe consequences

Answer 2

duodenum and proximal jejunum via carrier mediated active transport

Thiamine pyrophastate (TPP)

transketolase, alpha ketoglutarate dehydro, pyruvate dehydro

high metabolic demand and glucose intake

dec carb/AA metabolism

dec Ach for neural fxn

Question 3

Thiamine def due to

more common in

In western countries, primary dec results from

def can occur in dz such as

procedures at risk include

Answer 3

poor dietary intake

rice based diets, milled rice/grains contain little

alcoholism- interferes w absorption, dec synthesis of TPP and inc urinary thiamine excretion

cancer, hyperemesis gravidarum, anorexia, bariatric surgery

Roux en y, biliopancreatic diversion (bypass duodenum and prox jej)

Question 4

Early stages of thiamine def

prolonged def causes

Wet beriberi sx

such a

Answer 4

nonspecific (anorexia, irritability)

beriberi (wet or dry)

CV (impaired myocardial energy metabolism)

cardiomegaly, tachycardia, CHF, peripheral edema, PN

Question 5

Dry beriberi sx

diminshed reflexes in

Maternal thiamine def leads to

apparent at

clinical features

tx

Answer 5

symmetric PN of motor/sensory systems

legs- difficulty rising from squat

infantile beriberi in breastfed babies

2-3 mnths

cardiomegaly, tachycardia, loud piercing cry, cyanosis, dyspnea, vomiting

parenteral thiamine

Question 6

Alcoholic pt may present w

sx include

Wernicke-Korsakoff syndrome

Answer 6

Wernicke’s encephalopathy

horizontal nystagmus, ophthalmoplegia, cerebellar ataxia, mental impairment

Wernicke’s enceph w memory loss an confabulatory psychosis

Question 7

Thiamine def detected w

low ETKA indivates

if def suspected,

Answer 7

thiamine levels or measuring ETKA before/after administering TPP

thiamine def (not readily available)

admin replacement first

Question 8

Alcoholic pt being refed, admin

admin first before

carb repletion w/out thiamine results in

Tx for thiamine def

pt typically ____, except for

Answer 8

thiamine

refeeding/admin glucose

acute thiamine def

IV thiamine, followed w oral

improves, Wernicke-Korsakoff

Question 9

Toxicity

Answer 9

minimal, good renal clearance