27/02/2026
One of the patterns I frequently notice in clinic is low haemoglobin or fatigue despite what appears to be adequate iron intake.
In these cases, the issue is not always iron deficiency but iron utilisation.
Iron metabolism relies on nutrient synergy. Vitamin A, in its retinol form, plays an important regulatory role in iron mobilisation, red blood cell production and oxygen delivery. One key mechanism involves ceruloplasmin, a copper-carrying protein produced in the liver that helps iron move into circulation and supports haemoglobin formation.
When this pathway is disrupted, iron can remain stored rather than effectively used, which may contribute to symptoms such as fatigue, cold extremities or reduced stamina even when iron intake seems sufficient.
Modern dietary patterns may also contribute to suboptimal vitamin A status. Preformed retinol is found primarily in animal foods such as liver, which many people rarely consume. Some individuals also rely heavily on beta-carotene from plant foods, yet genetic variation in the BCMO1 enzyme can reduce conversion efficiency into active retinol. Digestive, liver or bile-related factors may further influence absorption and utilisation.
In practice, supporting vitamin A status — whether through occasional liver consumption or a high-quality cod liver oil — can sometimes be a helpful piece of the puzzle when exploring iron balance and energy levels.
As always, context matters. Nutrients do not work in isolation, and understanding these interactions can often shift the clinical approach.
If this resonates with your symptoms or lab results, it may be worth exploring nutrient interactions rather than focusing on single nutrients alone.