Dietary magnesium deficiency decreases plasma melatonin in rats.
Level 5 - mechanism / opinion, no new human data
Preclinical animal experiment without human data
What was done
Male weanling Sprague-Dawley rats were fed either a magnesium-deficient diet (150 ppm) or a magnesium-adequate diet (1000 ppm) for four weeks. Animals were sacrificed at 4, 5, or 7 hours into their dark cycle, and plasma was collected and assayed for melatonin concentrations.
What was found
Rats fed the magnesium-deficient diet exhibited significantly lower mean (± SEM) plasma melatonin levels during the dark cycle compared to magnesium-adequate controls (50 ± 6.4 pg/mL vs. 75 ± 6.6 pg/mL, p = 0.0101). No obvious phase shift in the melatonin profile was detected between groups.
Why it matters
This study provides experimental in vivo evidence in rodents that dietary magnesium deficiency reduces circulating melatonin, supporting the proposed role of magnesium in serotonin N-acetyltransferase activity and melatonin synthesis.
Limits
This is a pilot study in male weanling rats and cannot be directly generalized to humans. The abstract does not report the total sample size (n), baseline melatonin measurements, or direct enzymatic assays of serotonin N-acetyltransferase.
Cited by
- supports Magnesium is a GABA agonist and affects the enzymatic conversion of serotonin into melatonin.