Micronutrient Deficiencies and Their Public Health Impact: An Epidemiological Narrative Review

Abstract

Background: Micronutrient deficiencies, often referred to as “hidden hunger,” remain a major global public health challenge despite significant advances in nutrition and health systems. Deficiencies in essential micronutrients such as iron, vitamin A, iodine, zinc, and vitamin D contribute substantially to morbidity, impaired cognitive development, poor pregnancy outcomes, and increased mortality, particularly among vulnerable populations. This narrative review aims to synthesize epidemiological evidence on the prevalence, determinants, and public health impact of major micronutrient deficiencies worldwide.

Methods: A narrative review approach was employed by searching PubMed, Scopus, and Google Scholar for relevant literature published between 2010 and 2024. Additional data were obtained from authoritative sources including the World Health Organization, UNICEF, and global nutrition reports. Studies addressing epidemiological patterns, risk factors, and health outcomes related to micronutrient deficiencies were included and narratively synthesized.

Results: The review identified iron deficiency anemia as the most prevalent micronutrient disorder globally, with persistently high rates among women of reproductive age and children. Vitamin A, iodine, zinc, and vitamin D deficiencies also remain widespread, particularly in low- and middle-income countries. Although some regions have shown modest improvements over time, global trends indicate fluctuating prevalence and continued public health burden driven by poor dietary diversity, socioeconomic inequalities, infectious diseases, and gaps in nutrition surveillance and intervention coverage.

Conclusion: Micronutrient deficiencies continue to pose a significant global health burden despite existing interventions. Strengthening integrated public health strategies—including food fortification, supplementation, dietary diversification, and routine screening within primary health care—is essential to reduce the long-term health and socioeconomic consequences of these deficiencies and to support progress toward global nutrition and health targets.

Keywords: micronutrient deficiencies, anemia, nutritional epidemiology, public health, hidden hunger