Age 1-21 years old (muscle strength will be assessed only in children \>3 year old)
Estimated glomerular filtration rate (GFR) \< 90 ml/min/1.73m2 by bedside Schwartz formula \[height (cm) \*0.413 / serum creatinine (mg/dL)\]
Hemoglobin (Hb) more or equal than 9.0 at the previous clinic visit
Hb less than 11.5 g/dL in children younger than 5 years Hb less than 12.0 g/dL in children 5-12 years Hb \<12.5 g/dL in children 12-15 yrs and females \>15 yrs. Hb \<13.5 g/dL in males \>15 years (all at the previous clinic visit)
Children with transferrin saturation ≤ 20% AND serum ferritin ≤ 100 ng/mL will be randomized into one of the arms
You may not be if
Transferrin saturation \<5%
Serum ferritin \< 10 ng/mL
Iron therapy or erythrocyte stimulating agents (erythropoietin) therapy within 3 months prior to randomization
Blood transfusion within 4 months prior to enrollment
Children on hemodialysis
Rapidly deteriorating kidney function or expectation for transplantation or dialysis in less than 3 months
Pregnancy and breast-feeding
Clareo Health | Oral Iron in Children With Chronic Kidney Disease