Aluminium: the pathway in the body

Aluminium is part of the pathway “Aluminium”. This page shows the whole pathway; the station of Aluminium is highlighted.

Where this laboratory value sits: Environmental aluminium — food, water, air, skin. Aluminium is a common element of the earth's crust. It reaches the gut with food, drinking water and some medicines, and the lungs with dust; only a very small part passes through the skin. Source 1, 5

In brief

Aluminium is a light metal and the most common metal of the earth's crust. In the body it is present as a trivalent ion, binds to transferrin in the blood and is excreted mainly by the kidney.

The pathway step by step

1. Environmental aluminium → In the digestive tract In the acidic stomach part of the aluminium dissolves into trivalent ions. In the gut, phosphate binds aluminium into poorly soluble compounds; citrate keeps it dissolved. Source 1, 3
2. In the digestive tract → Across the gut wall · Citrate Only a small share of the aluminium crosses the gut wall into the blood, partly by passing between the cells. Source 1
3. Across the gut wall → Aluminium in the blood · Transferrin In the blood aluminium binds mainly to transferrin, the transport protein of iron. A smaller part is dissolved as a citrate compound. Source 3, 2
4. Aluminium in the blood → Deposition in bone Part of the aluminium is deposited in bone, where it is bound in the mineral matrix of calcium and phosphate. Source 1
5. Into the cell → Trivalent ion Inside the cell aluminium is present as a trivalent ion. It binds preferentially to oxygen atoms, for example to phosphate groups of ATP and other molecules. Source 4, 2
6. Trivalent ion → Magnesium sites Inside the cell magnesium binds to ATP and to many enzymes. Aluminium binds to the same sites, much more firmly, and is released from them far more slowly. Source 4
7. Magnesium sites → Calcium sites Binding sites for calcium, for example in calcium-binding proteins, can also hold aluminium. Source 4
8. Into the cell → Iron binding sites Aluminium and trivalent iron are similar in charge and size. This is why aluminium binds to the iron binding sites of transferrin. Source 3, 2
9. Iron binding sites → Back into the blood · Citrate From the tissues aluminium returns to the blood. There it forms small, dissolved compounds with citrate. Source 1, 3
10. Back into the blood → Excretion in urine The small citrate compounds pass the filter of the kidney. Most of the aluminium that has reached the blood leaves the body with the urine. Source 1

Cofactors in this pathway

• Iron — Aluminium occupies the iron binding sites of transferrin and is carried in the blood this way Source 3, 2In the ORY catalogue as a laboratory value: Eisen
• Magnesium — Aluminium binds to the magnesium sites of ATP and enzymes, more firmly than magnesium itself Source 4In the ORY catalogue as a laboratory value: Magnesium
• Transferrin — Transport protein of iron; binds aluminium in the blood and carries it into cells via its receptor Source 3, 2
• Citrate — Keeps aluminium dissolved in the blood; in this form it passes the filter of the kidney Source 1, 3
• Calcium — Calcium binding sites in proteins and in the bone matrix can hold aluminium Source 4, 1
• Phosphate — Forms poorly soluble compounds with aluminium in the gut and in the mineral matrix of bone Source 1, 3

Sources

1. Priest ND. The biological behaviour and bioavailability of aluminium in man, with special reference to studies employing aluminium-26 as a tracer: review and study update. J Environ Monit 2004 · PubMed 15152306
2. Exley C, Mold MJ. The binding, transport and fate of aluminium in biological cells. J Trace Elem Med Biol 2015 · PubMed 25498314
3. Harris WR, Berthon G, Day JP et al. Speciation of aluminum in biological systems. J Toxicol Environ Health 1996 · PubMed 8772798
4. Macdonald TL, Martin RB. Aluminum ion in biological systems. Trends Biochem Sci 1988 · PubMed 3072691
5. Flarend R, Bin T, Elmore D et al. A preliminary study of the dermal absorption of aluminium from antiperspirants using aluminium-26. Food Chem Toxicol 2001 · PubMed 11267710

Whole pathway: Aluminium

Related pathways

• Nickel — into the cell

As of 2026-09-18. Draft, written by Claude to schema v2; sources checked in PubMed; expert approval pending
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