Riboflavin intake and status and relationship to anemia.

This article focuses on riboflavin (vitamin B2), its metabolic roles, assessment of biochemical status, dietary sources, and its relationship with anemia across different populations. Riboflavin, primarily in its coenzyme forms flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), is essential for redox reactions involved in energy production, antioxidant protection, and metabolism of other B vitamins. The erythrocyte glutathione reductase activity coefficient (EGRac) is the main functional biomarker for riboflavin status, with values ≥1.40 commonly indicating biochemical deficiency. While riboflavin deficiency has been well-documented in low-income and rural populations, emerging evidence shows biochemical deficiency also occurs in middle- and high-income countries despite generally adequate dietary intakes. Biochemical riboflavin deficiency, even without overt clinical symptoms, may contribute to anemia by impairing iron metabolism and erythrocyte production, particularly among women and children. The article highlights variability in riboflavin status assessment methods, dietary reference intakes, and supplementation trial outcomes, underscoring the need for standardized biomarkers and further research on riboflavin’s role in anemia in diverse populations.