Nutritive utilization of Ca and Mg in Mg-deficient rats: a recovery study

Recovery from Mg deficiency was studied in adult Wistar rats fed a semisynthetic diet containing 0.04% Mg in the form of magnesium carbonate. Daily administration of a diet containing recommended levels of calcium carbonate to Mg-deficient rats led to the recovery, within the first seven days of treatment, of normal values in most of the parameters studied: gain in weight/day, and Mg retention and content in the Longissimus dorsi muscle and femur. Mg levels in whole blood, however, did not fully recovery until the second week of treatment. Net Ca absorption (ADC) and balance were significantly higher in Mg-deficient rats than in controls and remained elevated although to a lesser extent in the femur. Longissimus dorsi muscle, blood and plasma were unchanged by Mg deficiency.