Effects of a high-calcium diet on serum insulin-like growth factor-1 levels in magnesium-deficient rats

Magnes Res. Jul-Sep 2012;25(3):126-30. doi: 10.1684/mrh.2012.0320.


In order to clarify the effects of a high-calcium (Ca) diet on bone formation in magnesium (Mg)-deficient rats, this study focused on the effects of a high-Ca diet on serum insulin-like growth factor-1 (IGF-1) levels. Male rats were randomized by weight into four groups, and fed one of four experimental diets containing two different Mg concentrations (0.05% (normal-Mg) or Mg-free (Mg-deficient)), and two different Ca concentrations (0.5% (normal-Ca) or 1.0% (high-Ca)) for 14 days. Serum concentrations of osteocalcin and IGF-1 were significantly lower in rats fed the Mg-deficient diet than in rats fed the normal-Mg diet. On the other hand, dietary Ca concentration had no significant influence on serum concentrations of osteocalcin and IGF-1. This study suggested that: 1) a high-Ca diet has no preventive effects on the decreased bone formation seen in Mg-deficient rats; and 2) a high-Ca diet does not enhance serum IGF-1 levels in Mg-deficient rats. Moreover, unchanged serum IGF-1 concentrations may contribute to the decreased bone formation seen in Mg-deficient rats receiving a high-Ca diet.

MeSH terms

  • Animals
  • Calcium / administration & dosage
  • Calcium / blood
  • Calcium / metabolism
  • Calcium / pharmacology*
  • Diet*
  • Insulin-Like Growth Factor I / analysis*
  • Insulin-Like Growth Factor I / metabolism
  • Magnesium / blood
  • Magnesium Deficiency / blood*
  • Magnesium Deficiency / metabolism
  • Male
  • Rats
  • Rats, Wistar


  • Insulin-Like Growth Factor I
  • Magnesium
  • Calcium