After being absorbed from foods and supplements, magnesium passes through the gastrointestinal tract (GI) via the mouth, esophagus, stomach, and the small and large intestines. When the magnesium compound reaches the stomach, the acidic environment starts to dissociate magnesium ions which bind with water molecules. Magnesium is absorbed primarily in the lower part of the small intestines and passes from the villi, tiny finger-like surfaces inside the small intestine, and into capillaries, blood vessels surrounding the small intestine.
Magnesium Absorption Categories:
Magnesium that is not absorbed in the small intestine travels to the large intestine, where a small amount is also absorbed. Typical magnesium absorption is broken down into three categories:
40% of magnesium is absorbed in the small intestine
5% is absorbed in the large intestine
55% leaves the body as waste
Note: These figures may vary. For instance, certain forms of magnesium supplements, such as magnesium oxide, (have a low absorbable magnesium potency).
Figure 1: Magnesium Absorption Pathways
The latest studies have also shown that there are two different transport systems for magnesium:
Active transcellular transport at low concentrations.
Active transcellular uptake occurs by a recently identified magnesium channel called TRPM6 (transient receptor potential channel 6), which is expressed along the brush border membrane of the small intestine.1 This is where magnesium-amino acid complexes can be absorbed intact.
Passive paracellular pathway at high intestinal concentrations.
The passive paracellular pathway is responsible for 80-90% of magnesium uptake in the intestinal tract. Passive pathways work more effectively in an acidic (lower pH) environment, which is why magnesium absorption is optimal on an empty stomach and away from other minerals, drugs, fibers, and alkalizing agents
Figure 2: Magnesium Absorption in the Human Small Intestine
The following factors contribute to higher magnesium levels:
1. Higher intakes of magnesium-rich foods, using magnesium bath salts and magnesium oil, or taking oral magnesium supplements.
2. Higher absorption of magnesium in the small intestines, in the case of oral and dietary magnesium.
3. Lower elimination as waste through the gastrointestinal “GI” tract.
4. Lower excretion by the kidneys.
Advantages of Amino Acid Forms of Magnesium
(Such as 100% fully reacted Magnesium Glycinate)
1. The glycine molecules occupy the reactive sites of magnesium, reducing its ability to bind with other substances that reduce absorption (such as medications or plant compounds like phytates).
2. When magnesium is bonded to glycine it reduces the binding of water which could reduce the frequently encountered problem of loose stools.
3. Amino acids like glycine increase solubility of the whole compound, improving bioavailability.
4. A portion of the magnesium – amino acid compound may be absorbed via the amino acid active transport pathway.
5. An additional portion of the magnesium – amino acid compound may be absorbed via the active transcellular transport pathway.
6. The presence of an amino acid, such as glycine, may help lower intestinal acidity towards a pH that would improve passive paracellular transport
REFERENCES
Blaine et al. Renal Control of Calcium, Phosphate, and Magnesium Homeostasis Clin J Am Soc Nephrol. 2015 Jul 7; 10(7): 1257–1272
Dr. Paul Hrkal is a board-certified Naturopathic doctor with a passion to apply innovative and evidence-based nutritional, biological, and supplemental interventions to address underlying metabolic, endocrine and immunological dysfunctions. He is strong advocate of integrative medical education frequently writing and lecturing to both healthcare practitioners and public audiences. He also is the medical director for Advanced Orthomolecular Research, a leading Canadian natural health product company, and maintains a clinical practice in the Toronto area.
Intermittent fasting is a hot topic in the diet and nutrition world. There are many books, blogs, celebrities and even apps touting the many health benefits of this pattern of energy consumption. The question is whether there is sufficient clinical research to supports these claims. Intermittent fasting has been a part of religious practices for centuries. Christian, Muslim, Buddhist, Hindu and Jewish populations all perform intermittent fasting at different times throughout the year. Clinical studies on intermittent fasting are still quite limited and what we do know comes mostly from: animal studies, a handful of human trials with small sample
The scientific community has known for some time that different people respond differently than others to similar environments, and this is also the case with nutrition. After all, we’ve all heard a friend say that a particular diet worked wonders for them, but when we try the same program, we don’t see the same success. Wouldn’t it be great if there were a way to know whether your genetic blueprint was compatible with a particular diet or exercise regimen? Or whether you have specific sensitivities to certain foods? And what if you could understand your genetic susceptibility to stress or
High blood pressure is a dangerous condition that often leads to serious and sometimes fatal consequences. If you have been diagnosed with pre-high blood pressure it’s critical that you act immediately before the condition worsens into full-blown high blood pressure. If you already have high blood pressure, you should know that high blood pressure management is possible. Here are some tips for maintaining healthy blood pressure. 1. Quit Smoking There are lots of reasons to quit smoking, but did you know smoking increases the risk of high blood pressure? The very best thing you can do for your health is