REF-969 · Govus et al., 2015 · PLoS One, Vol. · Paper · PubMed

Pre-Altitude Serum Ferritin Levels and Daily Oral Iron Supplement Dose Mediate Iron Parameter and Hemoglobin Mass Responses to Altitude Exposure

Blimited evidenceMeasured on a mixed groupWritten before October 2026, being re-checked

The authors asked how daily oral iron supplementation influences the change in haemoglobin mass (Hbmass) and iron parameters after 2-4 weeks of moderate altitude exposure. Haematological data from 178 athletes exposed to 1,350-3,000 m were analysed by linear regression.

Hbmass rose more in athletes who took oral iron daily than in those who took none, and serum ferritin fell in the unsupplemented athletes while it rose in those on the higher dose. The authors conclude that oral iron during 2-4 weeks of moderate altitude may enhance Hbmass production and help maintain iron balance in some athletes with low pre-altitude iron stores.

Participants

n=178 athletes (98 males, 80 females) exposed to moderate altitude (1,350-3,000 m). Sport and competitive level are not given in the abstract.

Protocol

Altitude exposure of 2-4 weeks (mean ± s: 21 ± 3 days) at 1,350-3,000 m.
Athletes grouped by daily oral iron supplement: nil, 105 mg or 210 mg.
Linear regression on Hbmass, total iron incorporation (TII) and blood iron parameters — ferritin and transferrin saturation (TSAT).

Key Results

Hbmass change from pre-altitude: 1.1% [-0.4, 2.6] with nil, 3.3% [1.7, 4.8] with 105 mg and 4.0% [2.0, 6.1] with 210 mg of oral iron daily.
Serum ferritin: decreased by -33.2% [-46.9, -15.9] with nil and by 13.8% [-32.2, 9.7] with 105 mg, but increased by 36.8% [1.3, 84.8] with 210 mg daily.
Total iron incorporation: greater in both supplemented groups than in non-supplemented athletes (0 versus 105 mg: d = -1.88 [-2.56, -1.17]; 0 versus 210 mg: d = -2.87 [-3.88, -1.66]).

Practical Application

In 178 athletes (98 males, 80 females) who spent about three weeks (21 ± 3 days) at 1,350-3,000 m, haemoglobin mass rose 1.1% with no iron supplement, 3.3% with 105 mg and 4.0% with 210 mg of oral iron a day, and ferritin fell by about a third in those who took none — a retrospective analysis, not a randomised trial. To "do I need iron for an altitude camp?": iron status is part of the camp's result, so it is measured and discussed with a doctor before the camp, not after.
An unsupplemented camp drained iron stores: ferritin fell in the nil group, and the interval for the Hbmass change in that group includes zero.
The authors' conclusion is cautious — "may enhance", "in some athletes with low pre-altitude iron stores". It is not a case for every athlete to take iron.
Not from this paper; the base's own practice: iron is a blood-test decision made with a physician, never a default supplement, and the dosing schedule is a medical question (SYNTH-06).

Limitations

Retrospective and observational: iron dose was not randomised, so athletes given more iron may have differed in iron status or in other ways.
The abstract gives no ferritin thresholds and does not say how pre-altitude ferritin was modelled, although the title names it as a mediator.
No performance outcome; Hbmass and iron parameters only.
Sport, level, altitude method and the iron preparation are not described in the abstract.
Written from the abstract and record metadata only (full text not read).
How this entry was checked and changed
Why this level

observational, non-randomised, n=178; iron dose was not assigned by the investigators