Best absorbed form of magnesium
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Best Absorbed Form of Magnesium
Introduction to Magnesium Bioavailability
Magnesium is a crucial mineral for numerous physiological functions, including muscle and nerve function, blood glucose control, and bone health. However, the bioavailability of magnesium varies significantly depending on its form. Understanding which forms of magnesium are best absorbed can help in choosing the most effective supplements.
Organic vs. Inorganic Magnesium Compounds
Research consistently shows that organic magnesium compounds are generally better absorbed than inorganic ones. A systematic review comparing different forms of magnesium found that inorganic formulations, such as magnesium oxide, are less bioavailable compared to organic forms like magnesium citrate and magnesium malate1 3. This is crucial for individuals looking to maximize their magnesium intake through supplements.
Dose-Dependent Absorption
The absorption of magnesium is dose-dependent, with higher doses leading to lower fractional absorption. For instance, a study measuring magnesium absorption from various intakes found that while absorption increased with higher doses, the percentage of magnesium absorbed decreased progressively2. This curvilinear relationship suggests that the body has a limited capacity to absorb magnesium efficiently at higher doses.
Specific Organic Magnesium Compounds
Among organic magnesium compounds, certain forms have shown superior absorption rates. Magnesium citrate and magnesium malate are particularly effective, with studies indicating that these forms increase magnesium levels in tissues more efficiently than others3. Additionally, magnesium acetyl taurate has been noted for its ability to increase brain magnesium levels, making it a potentially valuable option for cognitive health3.
Impact of Formulation on Absorption
The formulation of magnesium supplements also plays a significant role in their bioavailability. For example, enteric-coated magnesium chloride has been found to have much lower bioavailability compared to magnesium acetate, suggesting that the coating can impair absorption2. This highlights the importance of choosing the right formulation to ensure optimal magnesium uptake.
Predicting Bioavailability
In vitro tests, such as those using the Simulator of the Human Intestinal Microbial Ecosystem (SHIME®), have been effective in predicting the bioavailability of different magnesium supplements. These tests have shown a wide variation in absorption and dissolution among various magnesium products, and poor in vitro bioavailability often translates to poor in vivo results4. This provides a reliable method for assessing the effectiveness of magnesium supplements before human trials.
Conclusion
In summary, organic magnesium compounds like magnesium citrate, magnesium malate, and magnesium acetyl taurate are generally better absorbed than inorganic forms. The absorption of magnesium is dose-dependent, and the formulation of the supplement can significantly impact its bioavailability. For those looking to optimize their magnesium intake, choosing the right form and formulation is essential.
Sources and full results
Most relevant research papers on this topic
Bioavailability of magnesium food supplements: A systematic review.
Organic magnesium formulations are more bioavailable than inorganic ones, but all supplements can maintain physiological levels in healthy individuals without prior deficit.
Systematic ReviewIntestinal absorption of magnesium from food and supplements.
Magnesium absorption from food and supplements is curvilinear, with less magnesium absorbed than calcium at higher intakes, and enteric coating can impair magnesium bioavailability.
Non-RCT
Highly CitedDose-Dependent Absorption Profile of Different Magnesium Compounds
Magnesium citrate increases muscle and brain magnesium levels dose-independently, while magnesium acetyl taurate increases brain magnesium levels when administered as a split dose.
Non-RCT
Animal Study
Rigorous JournalPredicting and Testing Bioavailability of Magnesium Supplements
Poor bioaccessibility and bioavailability in the SHIME model translate into poor dissolution and bioavailability in vivo, providing a valid methodology for predicting in vivo micronutrient bioavailability and effectiveness.
In Vitro Study
Very Rigorous JournalEffect of supplemented magnesium from magnesium oxide or dolomitic limestone upon digestion and absorption of minerals in sheep.
Magnesium supplementation in sheep increases preintestinal absorption, with magnesium oxide having the highest value, but both sources enhance mineral levels.
RCTMagnesium absorption: mechanisms and the influence of vitamin D, calcium and phosphate.
Magnesium absorption primarily occurs in the distal intestine, with vitamin D increasing it, but some absorption occurs independently, and interactions with calcium and phosphate remain unclear.
Literature ReviewHighly CitedMagnesium absorption from mineral water
Magnesium absorption from mineral water is mainly dose dependent, making comparisons between studies difficult.
The absorption of calcium and magnesium from the rumen and small intestine of the sheep.
Magnesium absorption in sheep occurs principally in the middle third of the small intestine, with variations observed in various species of laboratory animals.
Magnesium Absorption from Mineral Waters of Different Magnesium Content in Healthy Subjects
Magnesium from mineral waters is easily absorbed and has a similar absorption rate to pharmaceutical preparations.
RCTMagnesium absorption in the human small intestine. Results in normal subjects, patients with chronic renal disease, and patients with absorptive hypercalciuria.
Magnesium absorption in the human small intestine is mediated by a different transport process than calcium absorption, and may be dependent on vitamin D.
In Vitro StudyHighly Cited