The purpose of this study is to examine whether iron therapy in patients with intravenous iron deficiency anemia causes an increase in appetite. And whether this increase is mediated by the hormone ghrelin.

Prior to Iron treatment Investigator will sample subject blood for: counting blood, iron sector indices, renal function, electrolytes, and measure the level of ghrelin fasting plasma. In addition, the patient will fill a structured questionnaire that examines appetite levels. participants will be asked to answer a structured questionnaire which will include information on demographics, clinical data (fever, allergies, weight, height) and comorbidities. Additional data on laboratory tests, comorbidities, medication and regular blood and urine cultures results will be taken from the medical file. Iron treatment will be given according to local standard procedure . At the end of the treatment ghrelin levels and questionaire will be retaken .

iron deficiency anemia is defined: hemoglobin <12 gr / dl in women and Hb <13 gr / dl in men with ferritin <15 ng / ml.

Inclusion Criteria:

• Iron deficiency anemia that wasn't responded to oral treatment or wasn't tolerable due to side effects
• sign and dated informed consent form.

Exclusion Criteria:

• chronic inflammatory disease.
• chronic renal failure
• active cancer.
• active Infectious disease.
• non iron deficiency anemia.
• pregnancy.

Patients register to intravenous (IV) iron therapy due to iron deficiency anemia that wasn't responded to oral treatment or wasn't tolerable due to side effects and healthy volunteer.