Effects of low-dose iron supplementation in women with low serum ferritin concentration.

We studied effects of dose and treatment duration during low-dose iron supplementation in premenopausal, non-pregnant women, with initial serum ferritin and haemoglobin concentrations < 20 micrograms x l-1 and > or = 120 g x l-1, respectively. The study was randomized, double-blind and placebo-controlled. Three groups completed a 6-month study: placebo (n = 27), FE-9 (9 mg iron x day-1, n = 18) and FE-27 group (27 mg iron x day-1, n = 19). The supplement consisted of 11% heme and 89% inorganic iron. In FE-27, serum ferritin increased from (mean, 95% confidence interval) 11.8 (9.7; 14.4) to 25.3 (18.6; 34.4) micrograms x l-1 in 1 month, and remained stable after that (ANOVA: group effect, P = 0.0003). In both FE-9 and FE-27, blood haemoglobin levels increased from 136 (132; 140) to 142 (139; 145) g x l-1 in 1 month, remaining constant after that (group effect, P = 0.001). Hence, the 27 mg daily dose of organic/inorganic iron corrected both mild anaemia and storage iron depletion, whereas the 9 mg dose did not affect iron stores. Elongation of treatment duration above 1 month brought about only minor changes.