Comparison of two doses of elemental iron in the treatment of latent iron deficiency: efficacy, side effects and blinding capabilities.
Study Goal
The researchers aimed to determine an effective ferrous sulfate dose that improves iron stores while minimizing side effects and enabling blinding in studies of iron deficiency.
Results Summary
Both 60 mg and 80 mg iron doses significantly improved ferritin levels compared to placebo, with no significant differences in side effects or compliance between iron groups. However, a majority of participants correctly guessed their treatment allocation despite blinding.
Population
32 women aged 18-35 years (24 with latent iron deficiency, 8 iron-sufficient controls).
Effective Dosage
60 mg or 80 mg elemental iron daily.
Duration
16 weeks.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
ferrous sulfate dose (60 mg elemental iron) | increase | ferritin change scores | women (18-35 years) with latent iron deficiency (serum ferritin < 20 µg/L) | - | had significantly higher ferritin change scores than placebo groups | #1 |
ferrous sulfate dose (80 mg elemental iron) | increase | ferritin change scores | women (18-35 years) with latent iron deficiency (serum ferritin < 20 µg/L) | - | had significantly higher ferritin change scores than placebo groups | #2 |
iron (60 mg or 80 mg elemental iron) | increase | side effects | participants on iron who completed the trial | 77% | reported side effects | #3 |
placebo | increase | side effects | participants on placebo who completed the trial | 45% | reported side effects | #4 |
iron (60 mg or 80 mg elemental iron) | increase | treatment allocation guessing | participants on iron | 69% | correctly guessed their treatment allocation | #5 |
placebo | increase | treatment allocation guessing | participants on placebo | 56% | correctly guessed their treatment allocation | #6 |
iron (60 mg or 80 mg elemental iron) | increase | ferritin levels | participants with latent iron deficiency | - | were equally effective in normalising | #7 |
iron (60 mg or 80 mg elemental iron) | no change | side effects | participants between iron groups | - | no differences in side effects | #8 |
iron (60 mg or 80 mg elemental iron) | no change | compliance | participants between iron groups | - | no differences in compliance | #9 |
Adherence to iron supplementation can be compromised due to side effects, and these limit blinding in studies of iron deficiency. No studies have reported an efficacious iron dose that allows participants to remain blinded. This pilot study aimed to determine a ferrous sulfate dose that improves iron stores, while minimising side effects and enabling blinding. A double-blinded RCT was conducted in 32 women (18-35 years): 24 with latent iron deficiency (serum ferritin < 20 µg/L) and 8 iron sufficient controls. Participants with latent iron deficiency were randomised to 60 mg or 80 mg elemental iron or to placebo, for 16 weeks. The iron sufficient control group took placebo. Treatment groups (60 mg n = 7 and 80 mg n = 6) had significantly higher ferritin change scores than placebo groups (iron deficient n = 5 and iron sufficient n = 6), F(1, 23) = 8.46, p ≤ 0.01. Of the 24 who completed the trial, 10 participants (77%) on iron reported side effects, compared with 5 (45%) on placebo, but there were no differences in side effects (p = 0.29), or compliance (p = 0.60) between iron groups. Nine (69%) participants on iron, and 11 (56%) on placebo correctly guessed their treatment allocation. Both iron doses were equally effective in normalising ferritin levels. Although reported side-effects were similar for both groups, a majority of participants correctly guessed their treatment group.