1. A 65 yr old vegetarian comes with complaints of
tingling sensation in the hands and feet and numbness
in the extremities. He complains of frequent episodes
of giddiness and easy fatigability.
On Examination:
• Hb – 10 g/dl ( males- 14-16g/dl
females- 13-15g/dl)
• RBS – 80 mg/dl (70-140mg/dl)
• Serum Creatinine – 1 mg/dl (males- 0.7-1.4mg/dl,
females- 0.6-1.3mg/dl)
• Serum Calcium – 9mg/dl (9-11mg/dl)
2. • Vitamin B12 & Folic acid levels are reduced;
• Pallor present; Peripheral smear shows
Hypochromic macrocytes and excess of
reticulocytes.
3. a)What is your diagnosis?
Megaloblastic anemia
b)What are the active coenzyme forms of
Vitamin B12 & folic acid?
• Vit B12 – Methylcobalamine (major form seen
in blood), deoxy adenosylcobalamine (major
storage form in liver)
• Folic acid- 5, 6, 7, 8- tetrahydro folic acid
4. c)How is the active form of Folic acid related to Vitamin
B12 deficiency?
5. • The only way for generation of free THFA is
step 1 in the above reaction. When B12 is
deficient, free THFA cannot be formed and
folic acid is trapped as Methyl THFA.
6. d) List 2 biochemical reactions where Vitamin B12 acts
as a coenzyme.
