Higher bioavailability of magnesium citrate as compared to magnesium oxide shown by evaluation of urinary excretion and serum levels after single-dose administration in a randomized cross-over study

Abstract

Higher bioavailability of magnesium citrate as compared to magnesium oxide shown by evaluation of urinary excretion and serum levels after single-dose administration in a randomized cross-over study AbstractBackground: The development of several disorders, such as cardiovascular diseases, diabetes and osteoporosis, has been linked to suboptimal dietary magnesium (Mg) intake. In this context, a number of studies have tried to investigate which Mg compounds are best suited for Mg supplementation. Results suggest that organic Mg compounds are superior to the inorganic Mg oxide in terms of bioavailability, but a reliable statement cannot yet be made due to systematic differences in the applied study designs.Methods: This single-center, randomized, open, 2-period, 2-supplementation, 2-sequence, single-dose, cross-over study was conducted in 20 healthy male subjects of Caucasian origin to investigate and compare the bioavailability of Mg citrate, an organic Mg compound, and Mg oxide, an inorganic Mg compound. In order to reliably assess the bioavailability of both Mg compounds, subjects were supplemented with magnesium to saturate their Mg-pools before administration of each study product. The bioavailability of both Mg compounds was then assessed by measurement of the renally eliminated Mg quantity during an interval of 24 h after single-dose Mg administration (A e 0-24h ) as primary endpoint. Additionally, the Mg concentrations in a subset of leukocytes, in erythrocytes and in serum were measured on an exploratory basis.Results: After administration, A e 0-24h of magnesium was higher for Mg citrate than for Mg oxide. A e 0-24h for both study products was compared by analysis of variance (ANOVA), revealing an adjusted mean difference of 0.565 mmol, which was statistically significant at the 5% level (95% confidence interval of 0.212 to 0.918 mmol, p = 0.0034

Intestinal Absorption and Factors Influencing Bioavailability of Magnesium- An Update

“…Several chemical balance studies investigating urinary Mg 2+ excretion in humans found no significant differences between various Mg 2+ salts, including the comparison of organic with inorganic Mg 2+ salts [ 108 - 120 ], which indicated that all types of Mg 2+ are suitable to maintain or restore the Mg 2+ status. Some other studies observed a slightly better bioavailability of organic Mg 2+ salts under standardized conditions [ 112 - 116 ].…”

“…Likewise, a product study by Kappeler et al . (2017) observed a slightly higher bioavailability of Mg 2+ citrate as compared to Mg 2+ oxide using 24-h urinary Mg 2+ excretion as biomarker [ 116 ]. However, the difference in urinary Mg 2+ levels between Mg 2+ citrate (7.2±1.48 mmol) and Mg 2+ oxide (6.7±1.43 mmol)-although statistically significant-is marginal.…”

“…However, the results of the different studies are hardly comparable because the designs of the studies were different (Table 4 ). For example, Mg 2+ supplements were ingested together with a meal in some studies [ 38 , 108 - 111 , 113 - 116 ] or on an empty stomach or unclear conditions in others [ 47 , 112 , 117 ]. A study by Sabatier et al .…”

“…A similar Mg 2+ status between the probands is a prerequisite to compare the bioavailability of Mg 2+ . In other words, several studies did not adequately control Mg 2+ intake in the background diet or water intake during the treatment or intervention period [ 110 , 112 , 114 , 116 ]. Other studies simply encouraged subjects to avoid Mg 2+ -rich foods or avoid Mg 2+ supplements [ 108 , 113 , 115 ].…”

In Vitro Bioaccessibility of Ripe Table Olive Mineral Nutrients

“…Therefore, Crews' conditions were scarcely efficient for studying Mg bioaccessibility. According to the literature, Mg bioaccessibility may be influenced by the compound used in the diet; the ingestion of citrate was more efficient that oxide [20]. Mg absorption in healthy women is reported to be incremental (11-14%) when mineral water was consumed alone or in combination with meals [21].…”