Iron (55,8 a.m.u.) – vital element constituting in erythrocyte (haemoglobin) respiratory pigment structure. Iron metabolism is changing in some physiologic and pathologic conditions, including active growth, pregnancy, various endocrine disorders, inflammation, contagious diseases, constitutional pathologies, tumour diseases, haemorrhages, helminthic invasions. Intake of phosphates, oxalates, calcium, zinc, E vitamin, etc. is effecting the absorption of iron.

Iron metabolism is being actively regulated and several mechanisms are ensuring the sustainability of iron concentration in body by regulating absorption processes, transportation processes, utilization, deposition processes, and preventing the excretion with urine. Iron overdoses caused by some hereditary diseases or extreme intake could result in intoxication effects (tissue injuries caused by deposition of iron toxicity).

Very few amount of iron is being naturally excreted with urine. Rapid increase of iron concentration in urine could be caused by haemoglobinuria, proteinuria or iron overload.

Concentration of iron in hair and nails depends on many factors: level of intake and absorption, physiology and pathology processes balance of endogenous metabolism and individual properties of growth factors of these tissues and presence of external pollution factors, including hygienic and cosmetic procedures. Concentration of iron in male hair is higher than in female hair. Persons suffering from diseases of liver, spleen, chronic alcoholism manifests higher concentration of iron in their hair.