William Aird: ORAL IRON IN IRON DEFICIENCY ANEMIA

William Aird, Founder of The Blood Project, shared a post on X/Twitter:

“ORAL IRON IN IRON DEFICIENCY ANEMIA (IDA): I tweeted a poll asking how you would treat a case of uncomplicated IDA with oral iron. The options and responses are shown below:

There is no one right answer, though existing data (notwithstanding clinical practice guideline recommendations) support the use of a single dose of oral iron on alternative days. Most of you concurred.

The poll prompted a really good discussion. There was wide recognition that a dose of oral iron increases serum hepcidin at 24 hours, which inhibits further iron absorption (hence the rationale for every other day dosing).

There was broad appreciation for the value of alternate day dosing. Toby Richards, an international expert in iron deficiency, pointed out that while every other day dosing may improve fractional absorption, it is providing only 1/2 the total dose.

Vitamin C increases Fe absorption, but Toby Richards pointed us to an randomized controlled trial (RCT) showing that it does not improve ferritin or Hb in patients with IDA compared to iron alone. Vinson Yew responded that this particular study used antiquated 3x/day Fe dosing.

Now let’s examine the evidence. First the guidelines, or I should say guideline, since there is only one (BSG 2021) that provides a graded recommendation on oral iron for IDA. They recommend starting at one dose per day.

Now let’s break down the primary data. The first paper that prompted us to rethink our approach to oral Fe dose/frequency appeared in BLOOD in 2015. It suggested inferiority of high dose Fe and twice daily dosing.

A study in Lancet Haematol in 2017 of patients with non-anemic ID showed that providing iron supplements on alternate days and in single doses optimizes iron absorption and might be a preferable dosing regime.

Finally, a study in 2020 (same senior author as on the previous 2 studies) showed potential benefit (in terms of soft end points) in providing twice the daily target dose on alternate days (see Toby Richards’s comment above). Should we be using 120 mg every other day?

The last graphic shows the negative RTC examining the effect of vitamin C on oral iron therapy. Though the authors used a substandard oral Fe regimen, they should be commended for using more meaningful end points (Hb, ferritin) vs. the three studies above.”

Source: William Aird/X