The probable diagnosis is thiamine (vitamin B1) deficiency or beri beri. The active form of thiamine is thiamine pyrophosphate (TPP), which is required as a coenzyme in oxidative decarboxylation reactions involving pyruvate, alpha-ketoglutarate, and branched chain keto acids. Wernicke-Korsakoff syndrome is a neurological disorder caused by severe thiamine deficiency commonly seen in chronic alcoholics and is characterized by encephalopathy, cerebellar dysfunction, and psychosis.

1. Water Soluble Vitamin
Thiamine / (B1) /
Anti beri-beri factor
Dr. Santhosh Kumar N
Associate Professor of Biochemistry
No matter where you are in life,
no matter what your situation.
You can always do something.
“ Believe yourself ”
Have a great day to all

2. • A 40 year old male came to the hospital with complains of muscle weakness
difficulty to arise from squatting position and numbness in the legs. On examination
deep tendon reflexes were diminished, personal history he is chronic alcoholic and
takes unpolished rice in diet.
Laboratory investigations showed increased pyruvate, lactate & decreased RBC
transketolase activity in serum.
Questions:
• What is the probable diagnosis?
• What is the active form & mention their reactions?
• What is wernicke's- korsakoff syndrome?

3. • Sulphur containing vitamin
• Made up of pyrimidine ring & thiazole ring.
• Anti-neuritic vitamin (preventing or relieving
neuritis)
Neuritis: an inflammatory lesion of a nerve by pain, sensory disturbances & impaired or lost reflexes

4. SOURCES
– Layer of cereals (food grains)
– Unpolished hand pound rice have better nutritive value than polished
refined foods
– Yeast
– Wheat germ
– Pulses

5. RDA
– Adults: 2 to 3 mg/day
– Pregnancy and Lactation: 3 mg/day
– Children: 1.2 mg/day

6. Coenzyme
Required for growth and development of
the body
Essential for transmission of nerve
impulse

7. Biochemical functions …1
Metabolic role
• TPP is required in oxidative decarboxylation reaction of keto acids
Pyruvate Acetyl CoA +CO2
PYRUVATE DEHYDROGENASE
TPP
Alpha Ketoglutarate Succinyl CoA
ALPHA KETOGLUTARATE DEHYDROGENASE
TPP

8. Biochemical functions …2
• TPP is required for transketolase reaction
Ribose – 5 – P + Xylulose – 5 – P Sedoheptulose-7 -P + Glyceraldehyde -3-P
TRANSKETOLASE
TPP, Mg
(5C) (5C)
2+
(7C) (3C)
Erythrose – 4 – P + Xylulose – 5 – P Fructose -6 -P + Glyceraldehyde-3-P
TRANSKETOLASE
TPP, Mg
(4C) (5C)
2+
(6C) (3C)

9. Biochemical functions …3
• TPP is required for oxidative decarboxylation of branched chain Alpha-
Keto acids formed from Valine, Leucine and Isoleucine
TPP, FAD,
Lipoic acid

10. Deficiency Manifestations
BERI-BERI means weakness
• The symptoms are anorexia, dyspepsia, heaviness and weakness.
• Subjects feel weak and get easily exhausted.
• 3 TYPES :
–Wet beri-beri
–Dry beri-beri
–Infantile beri-beri

11. • Wet Beri-Beri
–Associated with involvement of CVS
–Edema of legs, face & trunk
–Heart is enlarged, palpitation & breathlessness,
–Decreased diastolic B.P & increased systolic B.P.
–Anorexia, dyspepsia (pin and needle sensation)
–Death due to heart failure.

12. Dry Beri-Beri
Associated with CNS
Anorexia,
loss of weight,
Muscle wasting polyneuropathy
Peripheral neuritis with sensory disturbance (numbness and
tingling sensation in legs and feet) leads to complete paralysis

13. Infantile Beri-Beri seen in
• Infants born to mothers suffering from thiamine deficiency
• Restlessness & sleeplessness,
• Rare conditions Anorexia, tachycardia, leads to cardiac failure

14. Wernicke-Korsakoff syndrome /Cerebral Beri-Beri
• It is common in chronic alcoholics
• Clinical features are encephalopathy (nystagmus, cerebellar ataxia) plus
psychosis
• Muscular weakness,
• Peripheral paralysis

15. Polyneuritis
• It is common in chronic alcoholics.
• Alcohol inhibits intestinal absorption of thiamine
& also interferes with conversion of thiamine to
TPP leading to thiamine deficiency
• May cause impairment of conversion of pyruvate
to acetyl-CoA.
• The result is increased plasma concentration of
pyruvate and lactate, leading to lactic acidosis.
Horizontal ridges in nails in thiamine deficiency

16. • A 40 year old male came to the hospital with complains of muscle weakness
difficulty to arise from squatting position and numbness in the legs. On examination
deep tendon reflexes were diminished, personal history he is chronic alcoholic and
takes unpolished rice in diet.
Laboratory investigations showed more pyruvate, lactate & decreased RBC
transketolase activity.
Questions:
• What is the probable diagnosis?
• What is the active form & mention their reactions?
• What is wernicke's- korsakoff syndrome?

17. Riboflavin / Vitamin-B2

18. • Dimethylisoalloxazine ring attached to
ribitol
• Heat stable and sensitive to light

19. Sources
• Liver
• Yeast
• Milk
• Kidney
• Egg
• Green leafy vegetables

20. RDA
– Adults - 1.0 mg/day
– Children - 1.0-1.8mg/day
– Pregnancy and lactation - 2.0 mg/day

21. Coenzyme form
• FMN (flavin mono nucleotide)
• FAD (flavin adenine dinucleotide)
–Oxidation-reduction reactions
–Involve in the electron transport chain & TCA Cycle
–Catabolism of fatty acids
Generation of FMN and FAD with the help of ATP.

22. FMN dependent reactions
• Amino acid oxidation (L – amino acid oxidase)
• Respiratory chain – NADH Dehydrogenase contains FMN
Electrons flow from NAD  FMN  CoQ

23. FAD dependent reactions

24. 1.5ATPs

25. FAD dependent reactions
• Pyruvate to Acetyl CoA (Pyruvate Dehydrogenase)
• α-Ketoglutarate to Succinyl CoA (α-Ketoglutarate dehydrogenase)
• Succinate to Fumarate (succinate dehydrogenase)
• Xanthine to Uric acid (Xanthine oxidase)
• Retinol (vitamin A) to retinoic acid by cytosolic retinal dehydrogenase.
• Tryptophan to Niacin.

26. Deficiency manifestation
Symptoms are confined to the skin and mucous membrane
– Skin becomes rough and scaly – Dermatitis
– Glossitis: Tongue becomes enlarged, tender, magenta
colored
– Cheilosis : Corner of the lips becomes swollen and
fissured

27.  Angular stomatitis/cheilitis (inflammation at the corners of
mouth)
 Proliferation of the bulbar conjunctival capillaries is the earliest
sign
 Normochromic normocytic anemia
Circumcorneal vascularization. Irregular ridges in the nails

28. Antivitamin
• “A substance that makes a vitamin metabolically ineffective”
Thiamine (B1) Riboflavin (B2)
Pyrithiamine
Oxythiamine
Galactoflavin
Dichlororiboflavin
Isoriboflavin

29. Thank You
“The future belongs to
those who believe in the
beauty of their dreams.”