Daily versus Intermittent Iron or Iron–Folic Acid Supplementation Across Life Stages for Improving Hematological and Health Outcomes Among Anemic Populations in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis Protocol

Anaemia remains one of the most prevalent nutritional issues worldwide, particularly in low- and middle-income countries (LMICs). Children, adolescents, women of reproductive age, and pregnant women are particularly vulnerable because of their higher iron needs during periods of growth and reproduction. Iron and iron–folic acid (IFA) supplements are widely used to prevent and treat anaemia, but there is still uncertainty about how often they should be taken daily or at spaced intervals. Understanding the best dosing schedule is important for improving treatment success, reducing side effects, and encouraging better adherence. This systematic review and meta-analysis will bring together existing research that compares the effectiveness and safety of daily versus intermittent oral iron or IFA supplementation across different life stages among people with anaemia in LMICs. The main outcomes will include changes in haemoglobin and serum ferritin levels, while additional outcomes will consider pregnancy-related effects, general health outcomes, and any reported side effects. By analysing findings from randomised controlled trials, quasi-experimental, and observational studies, this review aims to identify which regimen works best and is most practical to implement. The results will help inform future WHO recommendations and national anaemia control programs, supporting stronger, evidence-based decisions for anaemia prevention and management.