Dietary citric acid enhances absorption of aluminum in antacids

Clin Chem. 1986 Mar;32(3):539-41.


Ten healthy men ingested, twice daily between meals, during each of the seven-day experimental periods: (a) citric acid (as lemon juice), (b) Al(OH)3, or (c) Al(OH)3 + citric acid. Whole blood sampled after each dietary period was analyzed electrothermally after digestion with nitric acid. Moderate, but significant, increases in mean Al concentrations as compared with pretreatment values [5 (SD 3) micrograms of Al per liter] were seen after ingestion of either citric acid or Al(OH)3: 9 (SD 4) and 12 (SD 3) micrograms/L, respectively. Ingestion of both Al(OH)3 and citric acid resulted in a more pronounced, highly significant (p less than 0.001) increase in Al concentrations, to 23 (SD 2) micrograms Al/L, probably owing to formation and absorption of Al-citrate complexes.

MeSH terms

  • Adult
  • Aluminum / blood
  • Aluminum / metabolism*
  • Antacids / metabolism*
  • Citrates / pharmacology*
  • Citric Acid
  • Diet*
  • Humans
  • Hydrogen-Ion Concentration
  • Intestinal Absorption / drug effects*
  • Male


  • Antacids
  • Citrates
  • Citric Acid
  • Aluminum