HISTIDINE IS A HETEROCYCLIC AMINO ACID WHICH IS ESSENTIAL FOR INFANT GROWTH. IMPORTANT IN ERYTHROPOISIS AND LEUCOPOISIS MAKING IT OF USE IN THE TREATMENT OF ANAEMIA AND PROMOTES ZINC UPTAKE IN HUMAN ERYTHROCYTES. FOUND NECESSARY FOR THE MAINTENANCE OF MYELIN SHEALTHS AND IS ALSO USFUL IN AIDING AUDITORY DYSFUNCTION. REQUIRED FOR GROWTH AND FOR THE SURVIVAL OF PREMATURE BABIES. HISTIDINE PREVENTS CATARACTS,PROMOTES BONE GROWTH AND IT INCREASES CALCIUM ABSORPTION.