Children's bones and Magnesium
Magnesium (Mg) is a key factor in bone health, but few studies have evaluated magnesium intake or absorption and their relationship with bone mineral content status in children, especially those who are pre-pubertal.
Our primary objective was to evaluate magnesium metabolism in children and determine the relationship between magnesium intake and absorption and bone mineral status. Our secondary goal was to determine fractional and total magnesium absorption and estimated retention and compare these with recommendations including current Dietary Reference Intake values.
We measured Mg intake, absorption and urinary excretion in a group of 63 children age 4 to 8 yrs of age.
Absorption was determined using a dual-tracer stable isotope method in which 25Mg was given intravenously and 26Mg given orally with subsequent collection of a 72-hour urine and calculation of fractional dietary absorption from the relative recovery of the oral versus the intravenous tracer. Dietary Mg intake was determined using a 3-day weighed diet including one in-patient and two out-patient days. Bone mineral content and density were determined by total body Dual-Energy X-ray Absorptiometry.