Mg supplementation acutely affects intracellular Mg2+ in human leukocytes

Abstract

Intracellular Mg2+ ([Mg2+]i) is overall well regulated, however it is not known whether Mg supplementation may lead to its acute changes. Therefore we examined acute effect of Mg administered either in form of MgO or Mg citrate on total plasma Mg ([Mg]p) and [Mg2+]i in human leukocytes.Study design51 healthy individuals were randomized into 3 groups. One group received 300 mg Mg as MgO (n = 20), another group received 300 mg Mg as Mg‐citrate (n = 21). A control group contained 10 persons. Samples were obtained at 0 h and 1, 3, 9, and 24 h after supplementation. Probands ingested the supplement after breakfast. All probands received identical food and table water containing low‐Mg during the sampling time. [Mg]p was determined by AAS. [Mg2+]i was assessed as 340/380 nm mag‐fura 2 ratios in leukocytes of the probands.ResultsSignificant changes in [Mg]p could not be observed between groups. However supplementation with Mg lead to a significant increase of 340/380 nm ratios after 3, 9, and 24 h. After 9 and 24 h, the 340/380 nm ratios were significantly higher for Mg‐citrate than for MgO.ConclusionEven though only minor changes in [Mg]p could be detected already 3 h after Mg supplementation [Mg2+]i increased but returned to near normal after 24 h. Mg given as Mg‐citrate induced significantly higher increases of [Mg2+]i as if given as MgO.