6572
Methods : This study included 1013 adult patients on HD who did not have a malignancy , liver cirrhosis , thalassemia , iron deficiency , gastrointestinal bleeding , or a major operation within 6 months .
 Chemical: iron
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: iron 
Answer:
 Chemical: iron