Comparative bioavailability of magnesium forms: a PubMed literature synthesis and alignment with Swiss recommendations

Background: Magnesium supplementation is widely used to correct inadequate dietary intakes and to support various physiological functions, but bioavailability varies substantially according to the chemical form, solubility and pharmaceutical presentation of the salt. The Swiss dietary reference values (FSVO, 2022) set adult requirements at 300 mg/day for women and 350 mg/day for men. Objective: To provide a structured synthesis of the evidence from the PubMed literature on the comparative bioavailability of the main magnesium forms (oxide, citrate, chloride, lactate, aspartate and other organic salts), and to align these findings with Swiss recommendations and consumption data. Methods: Targeted narrative review of comparative clinical trials and systematic reviews addressing the bioavailability of magnesium supplements, complemented by an analysis of Swiss reference documents (FSVO, Swiss Society of Nutrition). Results: Human trials converge to show that organic salts (citrate, lactate, aspartate) and magnesium chloride exhibit higher bioavailability than the oxide. Studies combining in vitro and in vivo models confirm the influence of salt solubility and pharmaceutical form. Conclusion: Magnesium bioavailability depends on salt solubility, pharmaceutical formulation and unit dose. Several human trials document a relative advantage of organic and highly soluble inorganic salts over the oxide, although some authors emphasise that dose and an individual's magnesium status remain major determinants.