The Effect of Daily Iron Supplementation with 60 mg Ferrous Sulfate for 12 Weeks on Non-Transferrin Bound Iron Concentrations in Women with a High Prevalence of Hemoglobinopathies

There is a lack of evidence for the safety of untargeted daily iron supplementation in women, especially in countries such as Cambodia, where both anemia and hemoglobinopathies are common. Our aim was to assess serum non-transferrin bound iron (NTBI), a toxic biochemical that accumulates in blood when too much iron is absorbed, in Cambodian women who received daily iron supplements in accordance with the 2016 global World Health Organization (WHO) guidelines. We used fasting venous blood samples that were collected in a 2015 supplementation trial among predominantly anemic Cambodian women (18–45 years). Serum NTBI was measured with use of the FeROS™ eLPI assay (Aferrix Ltd., Tel-Aviv, Israel) in randomly selected sub-groups of women who received 60 mg daily elemental iron as ferrous sulfate (n = 50) or a placebo (n = 50) for 12 weeks. Overall, n = 17/100 (17%) of women had an elevated serum NTBI concentration (≥0.1 μmol/L) at 12 weeks; n = 9 in the Fe group and n = 8 in the placebo group. Elevated serum NTBI concentration was not associated with age, iron supplementation, transferrin saturation or severe hemoglobinopathies (p > 0.05). In this population of women with a high prevalence of hemoglobinopathies, we found that daily iron supplementation was not associated with elevated serum NTBI concentrations at 12 weeks, as compared to placebo.