Inclusion Criteria:  Personally signed and dated Informed Consent Form. Male or female, aged 18-50 years (inclusive) at the time of signing the Informed Consent Form. Iron deficiency as defined by a hemoglobin value 100-130 g/L (females) and 110-140 g/L (males) and a serum ferritin level <30 µg/L (with C-reactive protein level <10 mg/L). Generally healthy individual with no known significant health problems as judged by the Investigator (based on the screening questionnaire responses, medical history, the results of clinical laboratory tests performed at screening, and the results of examination of vital signs). Body mass index ≤25 kg/m2. Ability to understand and willingness to comply with all protocol required visits, assessments, and interventions.  Exclusion Criteria:  Occult gastrointestinal bleeding (as determined by the fecal occult blood test). Pronounced symptoms accompanying anemia (i. e., pronounced fatigue, dizziness, shortness of breath). Hemochromatosis or other iron-loading disorders. Known hemoglobinopathy (e. g., thalassemia). Any active or unstable concurrent medical condition (e. g., cancer, renal dysfunction, liver dysfunction). Presence of an inflammatory and/or autoimmune disorder (e. g., inflammatory bowel disease, systemic lupus erythematosus, rheumatoid arthritis, celiac disease). Partial or total gastrectomy or any other surgical procedure bypassing the duodenum. Known HIV, HBV, or HCV infection. Any active chronic or acute infectious disease requiring antibiotic treatment. Taking regular medication that could affect iron absorption (e. g., antacids, proton pump inhibitors, histamine H2 blockers). Use of any iron-containing medications or supplements within 30 days prior to screening and at any time throughout the duration of the study. Received blood transfusion within 12 weeks prior to screening or planned blood transfusion during the study period. Receipt of i. m. or i. v. injection of depot iron preparation within 30 days prior to screening or at any time during the study. Receipt of erythropoiesis stimulating agents within 30 days prior to screening or at any time during the study. Blood donation within the previous 30 days or planned blood donation during the study period. Scheduled or expected hospitalization and/or surgery during the course of the study. Intake of concurrent medications that could interfere with physical or mental performance (e. g., antidepressants, antihistamines, etc.). For women of childbearing potential: planning of pregnancy, current pregnancy, or lactation. Known allergies or severe adverse reactions to previous oral iron therapy or known hypersensitivity to any component of investigational products. Current participation in any other interventional clinical study or participation within 30 days prior to screening. Any other unspecified reason (laboratory abnormality, medical condition, or psychiatric or psychological disorder) which, in the opinion of the Investigator, makes the subject unsuitable for participation in the study.