This document discusses vitamin B12 and folic acid's effect on red blood cell production. It states that both are required for DNA synthesis and the maturation of red blood cells. A deficiency in either can lead to megaloblastic anemia characterized by large, fragile red blood cells with a shorter lifespan. The document also describes the interrelationship between folic acid and vitamin B12, where a deficiency in one can cause a functional deficiency in the other due to a process called the folate or methyl trap, where folic acid gets trapped and cannot be used, despite adequate tissue levels. Treatment for megaloblastic anemia requires both vitamin B12 and folic acid supplementation.

1. VITAMIN B12
&FOLIC ACID
EFFECT ON RBC
PRODUCTION
UTKARSHPANDEY
210201084
MBBS 1st Year

2. FOLIC ACID
(VITAMIN B9)
• Folic Acid also called as Folacin is largely found in
Green leafy vegetables, cereals, yeast, eggs etc.
• Milk is a poor source of Folic Acid .
• It is required for the synthesis of some amino acids,
Purines and Pyrimidine (Thymine).
• The active form is Tetrahydrofolate (THF/FH4). It is
synthesized from Folic Acid by enzyme
Dihydrofolate Reductase.
• Recommended Dietary Allowance (RDA) is 200
microgram.
• In women’s higher intake are recommended during
pregnancy (400microgram/day) and lactation
(300microgram/day).

3. EFFECT OF
FOLIC ACID
ON RBC
PRODUCTION
• Folic acid is important for maturation of
RBCs .
• It’s deficiency leads to decreased production
of purine and dTMP which blocks the DNA
synthesis . Block in DNA synthesis leads to
slowing down the maturation of
erythrocytes leading to Macrocytic RBC.
• These macrocytes has flimsy layer and are of
oval shape instead of biconcave. These
poorly developed cells are fragile and have a
shorter life span (half to one-third of normal)
.
• Hence it leads to Megaloblastic Anemia .

4. COBALAMIN
(VITAMIN
B12)
• Vitamin B12 is also known as Anti-Pernicious
Anemia Vitamin.
• It is synthesized only by microorganisms and not
by animals and plants.
• Recommended Dietary Allowance (RDA) is 1-2
microgram/day (adults) , 0.5-1.5
microgram/day (children), 3 microgram/day
(pregnancy and lactation) .
• Food of animal origin are the only sources if
Vitamin B12 . The sources are Liver, Kidney,
Milk, Curd, Eggers, Fish , Chicken etc.
• Curd is better than Milk due to synthesis of B12
by Lactobacillus.

5. EFFECT OF
VITAMIN B12
ON RBC
PRODUCTION
• The important disease associated with vitamin
b12 deficiency is Pernicious Anemia .
• It is characterized by low Hemoglobin levels,
decreased number of erythrocytes and
neurological manifestations.
• Some causes for occurrence of pernicious
anemia are as:--
Autoimmune destruction of gastric parietal cells
that secrete intrinsic factor.
Hereditary Malabsorption of B12, Partial /Total
gastrectomy .
Dietary Deficiency of B12 in strict vegetarians
countries like India, Srilanka.

6. INTERRELATION BETWEEN FOLIC ACID
&VITAMIN B12 ----- FOLATE TRAP
• The deficiency of either folate or vitamin b12 results in similar type of
anemia.
• Hence it suggests a biochemical interrelation between these two .

7. FOLATE /
METHYL
TRAP
HYPOTHESIS
• In vitamin b12 deficiency, plasma folate levels
are increased causing decline in activity of
enzyme homocysteine Methyltranferase.
• As a result the major pathway for conversion of
N5- methyl THF to Tetrahydrofolate is blocked
and entire body folate is trapped as N5-methyl
THF called as Folate or Methyl Trap.
• Although tissue folate levels are adequate/high ,
there is functional folate deficiency causing
development of Megaloblastic Anemia .
• Administration of Methionine shows partially
symptom correction so a combined therapy of
Vitamin B12 and Folic Acid is given to treat
patients with Megaloblastic Anemia .

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