biotin

1. WATER SOLUBLE VITAMIN
vitamin H- biotin
BY: SHAMAL SHIVNESH KUMAR

2. BIOTIN (vitamin B7)
 Present in mitochondria and cytosol
 Essential for cell growth
 Synthesized by fungi, bacteria and yeast
 Small amount is produced in humans large intestine
STRUCTURE
 Member of B complex group of vitamin
 Appears as white crystalline needle
 Sulphur containing
 2 condensed heterocycle (imidazolidine andthiolane)
 Side chain of valeric acid

3. FUNCTION
 Carboxylation reaction
Required for enzyme
 Pyruvate carboxylase
 Acetyl CoA carboxylase
 Propionyl carboxylase
*NOT ALL CARBOXYLATION REACTION REQUIRES BIOTIN

4. Absorption and transport
of biotin

5. Absorption of biotin
 Intestinal protease yields biotinyllysine
 Intestinal biotin amide amino hydrolase liberates free biotin
 Free biotin is absorbed in proximal part of small intestine
2 ABSORPTION MECHANISM INVOLVED:
 Facilitated transport
 Passive diffusion

6. CELLULAR UPTAKE AND TRANSPORT
TRANSPORT
 Na- dependent multivitamin transport assist in transportation of biotin into the
cell

7. SOURCES
 Egg yolk
 Liver
 nuts
 Vegetables
 Peanuts
 kidney

8. DEFICIENCY AND CLINICAL FEATURES
 Deficiency is very rare
CLINICAL FEATURES
 Severe dermatitis
 Weakness
 Nausea
 Alopecia
 Loss of appetite
 Muscle pain
 Weakness
Normal blood biotin level 400-1200ng/l
<400ngl – deficient state

9. CAUSE OF DEFICIENCY
 Parenteral nutrition
 Consuming raw egg
 Biotinidase deficiency