The molecular biology of human iron metabolism.
Level 5 - mechanism / opinion, no new human data
Narrative review describing biochemical mechanisms without original clinical trial or observational data.
PubMed 24868988 · doi:10.1309/lmf28s2gimxnwhmm
What was done
This narrative review summarizes the molecular biology, transport, and physiological roles of iron in humans, focusing on hematopoiesis, cellular storage structures, and the systemic consequences of iron deficiency and overload.
What was found
Normal adult total body iron ranges from 3.5 to 5.0 g, with 75% functioning in active physiological roles and 25% stored as ferritin or hemosiderin. Iron is distributed across hemoglobin (~67%), myoglobin (~3.5%), cytochromes (~3%), and nonheme enzymes (~2%). Ferritin is composed of 24 subunits consisting of light chains (19.7 kDa, 175 amino acids, chromosome 19q13.33) and heavy chains (21.1 kDa, 183 amino acids, chromosome 11q1), sequestering up to approximately 4,500 ferric ions per molecule. The text highlights that iron balance is controlled strictly through absorption rate because humans possess no physiological mechanism for active iron excretion.
Why it matters
It outlines the quantitative baseline for human iron distribution and storage architecture, clarifying why unregulated iron intake causes multi-organ toxicity and why impaired absorption rapidly leads to deficiency.
Limits
The abstract describes a non-systematic narrative review without primary clinical data, experimental cohorts, predefined search protocols, or quantitative risk estimates for specific clinical outcomes.
Cited by
- supports The human body has no active physiological mechanism for excreting excess iron.
- supports The human body has difficulty excreting or eliminating excess iron.