Anemia in type 2 diabetes mellitus: revisiting iron deficiency and the therapeutic role of ferrous bisglycinate

Anemia remains a major public health challenge in India and has important clinical implications for individuals with type 2 diabetes mellitus (T2DM). In this population, anemia is a significant comorbidity rather than an incidental finding, contributing to poorer glycemic control, increased risk of microvascular and macrovascular complications, reduced functional capacity, and overall diminished quality of life. Iron deficiency anemia (IDA) is the most prevalent in this patient population. These interconnected mechanisms contribute to both absolute and functional iron deficiency, yet anemia often remains underdiagnosed and undertreated in routine diabetes management. Conventional oral iron salts, though widely used, are frequently limited by gastrointestinal intolerance, interactions with dietary phytates, and poor long-term adherence, reducing their therapeutic effectiveness. Ferrous bisglycinate, a newer iron-amino acid chelate, has emerged as a promising alternative that addresses many of these limitations. Its chelated structure enhances bioavailability, minimizes gastrointestinal irritation, and allows more efficient absorption even in the presence of dietary inhibitors common in Indian diets. Clinical studies from India consistently demonstrate that ferrous bisglycinate can achieve significant improvements in Hb and ferritin levels at lower elemental iron doses compared with traditional iron salts, with better tolerability and higher adherence. This review consolidates current evidence on burden, mechanisms, and clinical relevance of anemia in T2DM and evaluates therapeutic advantages of ferrous bisglycinate. Together, these insights underscore the need for improved recognition of anemia in diabetes care and support the integration of newer, more tolerable iron formulations to enhance long-term clinical outcomes.