Is iron deficiency a major cause of the high prevalence of anemia in non-pregnant Cambodian women of reproductive age? : evidence from a cross-sectional survey and a randomized controlled trial

Despite a high prevalence of anemia among non-pregnant Cambodian women, recent reports suggest iron deficiency prevalence is low. If true, iron supplementation will not reduce anemia. In Phase I, we investigated factors associated with hemoglobin, ferritin, and soluble transferrin receptor (sTfR) concentrations in 450 women 18-45 years in Prey Veng province. Overall, 54% had a genetic hemoglobin disorder, 29.5% had anemia (hemoglobin 8.3 mg/L), respectively. The hemoglobin E homozygous genotype was associated with 50% (95% CI: 14%, 96%) and 51% (95% CI: 37%, 66%) higher mean ferritin and sTfR concentrations as compared to normal hemoglobin structure. These findings challenged the diagnostic accuracy of ferritin and sTfR to estimate iron deficiency. In Phase II, we measured the effect of oral iron (Fe) with or without multiple micronutrients (MMN) on hemoglobin concentration as a direct way to determine the extent to which iron deficiency (or other micronutrient deficiencies) was a cause of anemia. A total of 809 non-pregnant women 18-45 years with hemoglobin ≤117 g/L (HemoCue®) were recruited from Kampong Chhnang province to a 2x2 factorial double-blind randomized trial. Women received 12 weeks of daily Fe (60 mg), MMN (14 other micronutrients), Fe+MMN, or placebo capsules. Baseline anemia prevalence was 58% (Sysmex analyzer). Mean (95% CI) hemoglobin at 12 weeks did not differ in the Fe and Fe+MMN groups (121 [120, 122] vs. 123 [122, 124] g/L); both were higher than MMN and placebo (both 116 [115, 117] g/L, P<0.05). Mean (95% CI) increase in hemoglobin was 5.6 (3.8, 7.4) g/L (P