Inhibitory effects of zinc on magnesium balance and magnesium absorption in man

J Am Coll Nutr. 1994 Oct;13(5):479-84. doi: 10.1080/07315724.1994.10718438.


Objective: Both zinc (Zn) and magnesium (Mg) are widely used as nutritional supplements and the possibility was considered that Zn may interfere with the absorption of Mg, similar to previously reported results [1,2] obtained with the same dose of supplemental Zn on the absorption of calcium (Ca).

Methods: Mg absorption studies and metabolic balances of Mg and of Zn were carried out in three groups of adult males in a metabolic research unit during the intake of supplemental doses of 142 mg Zn as Zn sulfate (ZnSO4) during Ca intakes of 230, 500 and 800 mg/day.

Results: The Zn intake of 142 mg/day decreased the Mg balance and Mg absorption only during the 500 mg Ca intake compared to control values. However, the overall effect of the high Zn intake of the three groups combined, regardless of the Ca intake, was a highly significant decrease of Mg absorption and of the Mg balance.

Conclusion: Zn supplements of 142 mg/day decreased Mg absorption and the Mg balance significantly during all Ca intakes for the three groups combined.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Calcium / administration & dosage
  • Humans
  • Intestinal Absorption / drug effects*
  • Magnesium / metabolism*
  • Male
  • Middle Aged
  • Sulfates / administration & dosage
  • Sulfates / pharmacology*
  • Zinc / metabolism
  • Zinc Compounds / administration & dosage
  • Zinc Compounds / pharmacology*
  • Zinc Sulfate


  • Sulfates
  • Zinc Compounds
  • Zinc Sulfate
  • Magnesium
  • Zinc
  • Calcium