Thiamine (vitamin B1) is essential for energy metabolism, particularly in the nervous system, as it serves as a coenzyme in dehydrogenase reactions that produce ATP. Thiamine deficiency can lead to conditions such as beriberi and Wernicke-Korsakoff syndrome, primarily due to malnutrition or alcoholism. Symptoms of deficiency include neurological issues like confusion and ataxia, but they can be treated with thiamine supplementation.

1. THIAMINE (VITAMIN B1)
Maryam Fida (o-1827)
Source: Biochemistry – Lippincott’s Illustrated
Reviews
World Wide Web

2. ■ Thiamine pyrophosphate is the biologically
active form of the vitamin, formed by the
transfer of a pyrophosphate group (PPi) from
adenosine triphosphate (ATP) to thiamine
■ ATP → AMP + PPi

4. TPP serves as a coenzyme (a non-protein compound
that is necessary for the functioning of the enzyme)
■ In the formation or degradation of α-ketols by
transketolase (A)
■ In the oxidative decarboxylation of α-keto acids (B)

6. ■ ATP
 α-ketoglutarate Dehydrogenase
Pyruvate Dehydrogenase

7. ■ The oxidative decarboxylation of pyruvate and
α-ketoglutarate, which plays a key role in
energy metabolism of most cells, is
particularly important in tissues of the
nervous system.

8. ■ In thiamine deficiency, the activity of these two
dehydrogenase-catalyzed reactions is decreased,
resulting in a decreased production of ATP and
thus, impaired cellular function
■ Highly aerobic tissues like brain and heart are
affected first

9. ■ Thiamine deficiency is diagnosed by an
increase in erythrocyte transketolase activity
observed on addition of thiamine
pyrophosphate

10. Deficiency of Thiamine
1. Beri Beri
a) Adult Beriberi
i) Dry Beriberi
ii) Wet Beriberi
b) Infantile Beriberi
2. Wernicke-Korsakoff Syndrome
■ Due to
 Malnutrition
Alcoholism (second to malnutrition and
malabsorption)

11. ■ Spell beriberi as Ber1 Ber1 to remember
vitamin B1

12. Thiamine Deficiency
■ Beriberi: This is a severe thiamine-deficiency syndrome found in areas where polished rice is
the major component of the diet
■ Adult Beriberi is of two types:
 Dry Beriberi: Polyneuritis, symmetrical muscle wasting
 Wet Beri Beri: high – output cardiac failure (dilated
cardiomyopathy), edema
■ Infantile Beriberi is seen in nursing infants whose mothers are deficient in thiamine

13. Wernicke-Korsakoff syndrome
■ Thiamine deficiency, which is seen primarily in association with chronic alcoholism, is
due to dietary insufficiency or impaired intestinal absorption of the vitamin
■ Symptoms include
 Confusion, opthalmoplegia, ataxia (classic triad) +
confabulation, memory loss and a rhythmic to-and-fro
motion of the eyeballs (nystagmus)
 The neurologic consequences of Wernicke's syndrome are
treatable with thiamine supplementation