About one in four people worldwide suffer from iron ID, the most common micronutrient deficiency. Children, women of reproductive age, and those living in low- and middle-income nations are disproportionately affected. With effects ranging from decreased physical performance and quality of life in adults to increased risks during pregnancy, including low birth weight, preterm delivery, and maternal mortality, as well as impaired cognitive and motor development in children, it substantially adds to the global burden of disease. Though clinical and functional abnormalities, including exhaustion, immunological dysfunction, and cognitive deficiencies, can happen even in the absence of anemia, ID frequently occurs before IDA. According to the World Health Organization, iron deficiency anemia (IDA) affects 30% of the population worldwide, making it the most prevalent dietary deficiency. Reduced dietary iron and decreased iron absorption are additional contributing factors to IDA, even though gastrointestinal bleeding and women's menstruation are the most frequent causes. Restoring iron reserves and bringing hemoglobin levels back to normal should be the goals of treatment for patients with IDA. This has been demonstrated to enhance pregnancy outcomes, morbidity, quality of life, and the prognosis for chronic illnesses. Numerous chronic inflammatory diseases, such as inflammatory bowel disease, chronic kidney disease, and congestive heart failure, are associated with iron deficiency. An updated summary of the diagnosis and treatment of IDA in patients with chronic illnesses, both before and during pregnancy, will be given in this article. Along with a summary of the cost comparison of the various iron formulations now available on the market, we will go over the advantages and disadvantages of oral versus intravenous iron replacement in each group.