RESUMO
OBJECTIVE: To compare the effectiveness, compliance, and side effect profile between daily or three times weekly (TIW) oral iron supplementation regimens in treating iron deficiency nonanemia (IDNA) in National Collegiate Athletic Association (NCAA) Division 1 female track and field or soccer athletes. DESIGN: Prospective cohort study. SETTING: Division 1 collegiate athletics. PARTICIPANTS: Thirty-three NCAA Division 1 female athletes (18 track and field, 15 soccer). INTERVENTIONS: Daily or TIW dosing of ferrous bisglycinate. MAIN OUTCOME MEASURES: Serum ferritin (µg/L) was measured before and after 8 weeks of supplementation. Self-reported compliance and side effect profile was assessed by electronic survey every 2 weeks. RESULTS: The average main effect for the TIW regimen was a significant increase of 5.17 µg/L (95% CI: 0.86-9.47) in serum ferritin (p = .02). The average main effect for the daily regimen was a significant increase of 12.88 µg/L (95% CI: 4.84-20.93) in serum ferritin (p = .003). The estimated average effect of the treatment on the treated between regimens was a nonsignificant decrease of -7.17 µg/L (95% CI: -19.02 - 3.59) in serum ferritin (p = .17). Thus, the TIW regimen increased serum ferritin 7.17 units less than the daily regimen on average after 8 weeks of supplementation. The athletes following the daily regimen experienced significantly more nausea (p = .04) and constipation (p = .002) compared to the TIW regimen. There was no statistical difference in compliance between the two groups (p = .14). CONCLUSIONS: Both the daily and TIW regimens increased serum ferritin. Compared to the daily regimen, the TIW regimen produced a smaller increase in serum ferritin but less nausea and constipation.