Effect of iron-fortified rice on the hemoglobin level of the individuals aged more than six months: A meta-analysis of controlled trials

Fortification of staple food items with iron is a potential strategy to address anemia for a larger population. We reviewed studies to assess the impact of iron-fortified rice (IFR) on hemoglobin levels of individuals more than six months of age. We included studies assessing the effectiveness of IFR (with or without other micronutrients) conducted in any part of the world available in PubMed, Embase, Web of Science, Cochrane Library, Google Scholar, clinicaltrials.gov, International database of prospectively registered systematic reviews in health and social care (PROSPERO), unicef.org, and who.int databases and published from January 1, 1990 to April 1, 2019 (PROSPERO registration number: RD42020139895). We extracted the changes in hemoglobin, serum ferritin, and serum transferrin levels among the participants. Finally, data from 15 trials and their 21 subsets were analyzed. Mean difference in hemoglobin was 0.53 g/dl (95% CI: 0.26, 0.80, P < 0.001, I2 = 84%) in the IFR group compared to the control group. In the subgroup analysis after removing studies with small sample size and high risk for bias, a mean difference of 0.44 g/dl (95% CI: 0.20, 0.69, P < 0.001, I2 = 82%) was observed. No significant effect on serum ferritin or transferrin levels was observed. From this review it can be concluded that fortification of rice with iron can be adopted as an intervention to improve hemoglobin levels, especially in countries where rice is the major part food of staple diet. Research is needed on an optimal iron compound for fortification and the acceptance of IFR.