ABSTRACT
Protozoa Giardia lambelia is caused to diarrhea in human and other mammals in worldwide. Giardia colonizes in duodenum and earliest jejunum. It can cover the intestinal surface and causes the stateorrhea, malabsorbtion syndrome and absorb disorder of vitamins A, E and D. Investigation the effect of Giardia on the vitamin B12, folic acid and iron of patients were the purpose of this study. A total of 30 children with giardiasis, aged between 6-12 years-old, selected from 3000 patients, who were admitted to the Emam Khomeiny hospital and diagnosed by stool examinations [direct and formalin-ether methods]. Blood of patients and control were collected. Amount of vitamin B12 and folic acid were evaluated with radioimmunoassay and iron was evaluated with Ferene method. According to the data, folic acid in the patient had no significant difference against control but vitamin B12 and iron in the patient with giardiosis was less than control and the differences were significant [P=0.01, P=0.04 respectively]. According to the results diagnosis of giardiosis in the early stage may prohibit intestinal damage and clinical symptoms due to vitamins and mineral elements shortage in the children