1. THE B COMPLEX VITAMINS

2. INTRODUCTION
The vitamin B-complex refers to all of the known essential water-soluble vitamins except for vitamin C. These include thiamine (vitamin B1), riboflavin (vitamin B2), niacin (vitamin B3), pantothenic acid (vitamin B5), pyridoxine (vitamin B6), biotin, folic acid and the cobalamins (vitamin B12).

3. VITAMIN B₁ Properties White, crystalline substance Water-soluble
Heat labile
Unstable at high temperature and in alkaline medium
Stable in acid medium
On oxidation it gives a yellowish dye called thiochrome.

4. Sources
Rice polishing, dried yeast and wheat germ are rich sources of vit. B1.
Whole cereals like wheat, oats, legumes, oil seeds and nuts are good sources.
Milled cereals, vegetables, fruits, meat and fish are poor sources.
On milling, vit. B1 is lost from cereals.

7. Functions
Acts as a co-enzyme in carbohydrate metabolism
Require for the synthesis of glycine
It has a specific action on nerve tissue
Requires for the maintenance of normal gastro-intestinal tone and motility
Maintains normal appetite.

8. Deficiency Diseases
Beriberi - nervous, system affected, muscles become weak and painful paralysis can occur.
Heart failure, wet beriberi, dry beriberi, infantile beriberi, oedemia, children's growth is impaired, keto acids accumulate in the blood, wernicke’s-korsakoff’s syndrome etc.
Loss of appetite, fatigue, irritability, depression and constipation occur.

9. VITAMIN B₂, Riboflavin Properties Yellow crystals Soluble in water
Heat soluble in neutral and acid media
Destroy by light.

10. Sources Milk, liver, kidney, muscle, butter, chicken, fish, yeast,
cheese, raw egg, white grains,
green vegetable such as spinach, peanuts, fruits such as apple, orange etc

12. Functions
Precursor of coenzymes (FMN and FAD) in oxidation- reduction reactions of electron transport chain, fatty acid synthesis etc.
Essential for growth, essential for tissue oxidation related to carbohydrate, fat and protein metabolism.
Maintain mucosal, epithelial and ocular tissues.
Essential for normal vision.

13. Deficiency Diseases
Symptoms
Tongue sore at the corner of the mouth.
Loss of hair, skin becomes dry and scaly.
Arrest of growth.
Dermatitis around nose and lips, inflammation of tongue, angular stomatitis and cheilosis, photophobia, cataract etc.
Scrotal or vulval dermatitis, intense itching etc.
Disturb carbohydrate metabolism.

15. VITAMIN B₃