Bioavailability of magnesium diglycinate vs magnesium oxide in patients with ileal resection.
Level 2 - randomized trial
Double-blind randomized crossover trial in humans
PubMed 7815675 · doi:10.1177/0148607194018005430
What was done
A double-blind, randomized crossover trial in 12 patients with ileal resection compared the bioavailability of a single 100-mg dose of 26Mg-labeled magnesium diglycinate (chelate) with 26Mg-labeled magnesium oxide (MgO).
What was found
For the overall cohort, 26Mg absorption did not differ significantly between magnesium chelate and MgO (23.5% vs 22.8%). However, in the 4 patients showing the greatest impairment of absorption with MgO, absorption was significantly greater from the chelate (23.5% vs 11.8%; p < .05). Peak isotope enrichment occurred significantly earlier after the chelate than after MgO (mean difference 3.2 +/- 1.3 hours; p < .05), and the area under the enrichment versus time curve was greater after chelate ingestion (p < .05). The chelate was also reported to be better tolerated by all patients.
Why it matters
Oral magnesium repletion is difficult in patients with ileal resection due to malabsorption and laxative side effects. These findings indicate magnesium diglycinate is absorbed earlier in the intestine, likely via dipeptide transport, making it a viable alternative for patients with compromised absorption.
Limits
The study had a very small sample size (n = 12), and the absorption advantage was observed only in a subgroup analysis of 4 patients. The trial evaluated only a single 100-mg dose rather than sustained clinical repletion, and tolerability was not reported with quantitative metrics in the abstract.
Cited by
- contradicts Magnesium glycinate has an 80 percent absorption rate.