The required answers to the questions are as follows:
(a)Classification of vitamins
(i) Water soluble vitamins - vitamins Band C
(ii) Fat soluble vitamins - vitamins A,D,E,K
(b) Deficiency diseases
(i) Vitamin B 1 - beriberi
(ii) Vitamin C - scurvy
(iii) Vitamin D - rickets in children and Oestomalacia in adults.
 (iv)Iron - Anaemia
(v)Calcium - Rickets
(vi) Iodine - goiter
(c)Functions of Fats and Oil in the body
Supply the body with large amount of heat and energy.
Are stored as fuel reserve in the adipose tissues under the skin.
Are essential for healthy skin and hair.
Act as cushion for delicate organs of the body.
Carry fat soluble vitamins.
Helps to insulate the body and keep it warm.