It is an insignificant trace element in its aggregate amount (about 4g), but it performs a number of vital functions. Iron performs its tasks mainly in the composition of biologically active compounds:

• haemoglobin, myoglobin - the most important function of gas exchange with the environment (especially important are oxygen and carbon dioxide, which participate in respiration)
• Cytochrome - implementation of complex intracellular chemical reactions of Oxidases,
• hydroxylases - regulation of acid-alkali balance Transferrin,
• hemosiderin, ferritin - transport and storage of Iron for other chemical compounds. Iron metabolism has a number of features.

The trace element is absorbed in the intestine, but there is a certain limit that does not allow Iron to enter the body above this norm. That is, if you take food with a content of iron higher than several times the daily norm - only its "programmed" part will be absorbed, the rest will safely leave the body. This is the main difficulty in replenishing the deficiency of this trace element. Iron is lost with bile and through epithalaxia of the lining of intestines, it is also lost with nails, hair, urine, sweat; in women - also during menstruation.

Iron deficiency leads to decreased haemoglobin production, a condition called anemia - is one of the most common diseases of mankind. Diagnosis of anemia is the main indication for prescribing a blood test for iron. Excess iron is called "siderosis", which is possible either due to external ingestion of metal particles in the body (miners, electric welders), or due to the destruction of iron-containing enzymes (iron is "released" from bonds with other molecules and freely circulates in the bloodstream). The danger of siderosis lies in the deposition of the trace element in organs (for example, in the lungs).