Vitamin C added nothing to iron tablets, in one trial
In 440 adults with iron deficiency anaemia, haemoglobin at two weeks rose 2.00 grams per decilitre with vitamin C and 1.84 without. Ferritin at eight weeks matched too.
What the study found
Adding 200mg of vitamin C to iron tablets changed nothing
In 440 adults with iron deficiency anaemia, haemoglobin at two weeks rose 2.00 grams per decilitre with vitamin C and 1.84 without, a gap of 0.16 inside the trial's pre-set equivalence margin. Ferritin at eight weeks matched too, and side effects were identical at about 21%.
The caveat · Iron dose already near saturation
The iron dose was 100 milligrams every eight hours, high enough that absorption is already saturating and there is little room for an enhancer to help. Everyone in the trial was frankly anaemic, in whom absorption is already turned up. And this tested a vitamin C tablet taken with an iron tablet, not the vitamin C in a meal acting on the iron in food.