Certain organic compounds are required in small amounts in our diet but their deficiency causes specific disease. These compounds are called vitamins. Most of the vitamins cannot be synthesized in our body but plants can synthesize almost all of them. So they are considered as essential food factors. However, the bacteria of the gut can produce some of the vitamins required by us. All the vitamins are generally available in our diet. The term 'vitamin' was coined from the words vital + amine, since the earlier identified compounds had amino group. Vitamins are classified into two groups depending upon their solubility in water or fat namely-fat soluble vitamins and water soluble vitamins.

Answer the following questions:

(a) What is the other name of vitamin $\mathrm{B}_6$ ?

(b) Name the vitamin whose deficiency causes increased blood clotting time.

(c) Xerophthalmia is caused by the deficiency of which vitamin? Give two sources of this vitamin.

OR

(c) Why can't vitamin C be stored in our body? Name the disease caused by the deficiency of this vitamin.