The "uselessness" of MgO is one of the most deeply entrenched myths in the Internet Supplement Community. Most of the literature is misleading, since it looks only at a short timescale. However, MgO takes a long time to be fully absorbed. This short paper lays it out- it was in German, and since it was so short I'm pasting the entire Google translation here. I highlighted the key points in red. If you read German,
here's the source.
Bioavailability of organic and inorganic compounds
Von Sighart Golf
Of magnesium preparations, there is a whole series. They contain the mineral in an organic or inorganic compounds. For the absorption of the compound Magnesium plays no role.
A magnesium deficiency can be compensated by changes in diet on whole foods, the consumption of magnesium-rich mineral waters (more than 100 mg of magnesium / l) or the use of high-quality magnesium products. No or only a minor role played by the question of whether the used inorganic magnesium preparation (for example, chloride or oxide) or organic anions (such as citrate or aspartate) contains. The assumption of organic magnesium salts is the "better" because bioavailability magnesium is widespread, but not really. In fact, numerous studies show with valid measurement methods that all the examined magnesium compounds both pharmacologically and biologically and clinically equivalent. Although inorganic magnesium salts are chemically less soluble, but chemists measure the solubility of a salt in laboratory conditions (such as pH 7, 20 ° C, 1 bar, 1-molar, closed system), in the body but there are other conditions.
In the 1970s to 1990s, the Federal Health Office (BGA) has called on the market for magnesium supplements bioavailability studies, the study design of Lücker (1) was accepted by the BGA. In these studies were the magnesium storage study persons initially saturated with magnesium-rich food and after subsequent administration of the test formulations, the magnesium magnesium excretion measured in the urine. The studies showed that the tested availability of various inorganic and organic magnesium supplements under equivalence aspects must be considered within the range of 70 to 143 percent as bioequivalent. The intestinal absorption of magnesium is to Lücker independent of the administered type of connection.
Studies about absorbability
In recent years more publications have appeared with some different statements that magnesium would be better absorbed from organic and inorganic compounds. The listed studies point except the study of Coudray (2) However, any material weaknesses. Do you have a statement to better bioavailability of magnesium preparation, the following deficiencies to not. In the studies by Lindberg (3), fine (4), Firoz (5) and Walker (6), the urine collection period was less than one day and was thus not sufficient, since in this time, a substantial portion of the inorganic magnesium compounds not yet is absorbed. In the studies by Walker (6), Mühlbauer (7), Lindberg (3) the pre-analysis for the determination of magnesium in the urine was incorrect: The urine was not previously acidified with concentrated hydrochloric acid, 1 percent. Of the data necessary for calculating a magnesium balance specimen (three-day urine, three-day stool, serum / plasma) was missing in the studies by Lindberg (3), Walker (6) and Mühlbauer (7) at least one specimen .
Only the study by Coudray (2), which was carried out in rats, meets the above requirements for the determination of a complete balance of the magnesium uptake, retention and excretion. The test groups did not differ in body weight, intestinal solubility of magnesium (necessary for the absorption), magnesium in serum, erythrocytes and femur. In the absorption, excretion and retention of magnesium (which remained in the body), there was, however, in this study between MgO, MgCl 2, MgSO 4, MgCO 3, Mg acetate, Mg-pidolate, Mg-citrate, magnesium lactate and magnesium aspartate no significant differences.
A dynamic system
Magnesium can be absorbed from an almost insoluble compound such as magnesium in the human body. Basis of the absorption of magnesium from magnesium oxide is the law of mass action and processes in a dynamic system, such as at the contact point between the chyme and the epithelial cells of the intestine. Magnesium oxide is insoluble in water, but only sparingly soluble in water. It solves the following equation: 2 MgO + H 2 O -> Mg (OH) 2. Because of the equilibrium dissociation constant of this reaction is far on the side of magnesium oxide and water. Once after the above mentioned law primarily gone into solution magnesium is absorbed by the intestinal epithelium, the law of mass action has been disturbed as ever magnesium is removed from the balance. Thus, in the gut immediately released from the magnesium salt, which is absorbed in all areas of the intestine with the water flow. This process is continuous throughout the transit time of Nahrungsbreies who can stomach, intestine and colon take about two to three days. After resorption, which lasts approximately magnesia also two to three days, wherein magnesium citrate but only five hours, it is possible to the human body, magnesium from magnesium oxide actually comparable extent as receive from other compounds.
No matter what product is used, it must be taken over a long period, because magnesium remains only in the human body, even if there are molecules that bind to the mineral. These include ATP or DNA. The first biochemical adaptations improved magnesium supply, that is the provision of sufficient amounts of binding molecules can be observed after about four weeks. Also in this regard, inorganic and organic magnesium compounds act the same.
Literature
- Lücker, PW, et al., Mg Bulletin 15 (1993) 132
- Coudray, C., et al. Mg Research 18 (2005) 215-223.
- Lindberg, JS, et al., J. Am. Coll. Nutr. 9 (1990) 38-55.
- Fine, KD, et al., Clin. Invest. 88 (1991) 396-402.
- Firoz, M., et al., Mg Research 14 (2001) 257-262.
- Walker, AF, et al. Mg Research 16 (2003) 183-191.
- Mühlbauer, B., et al., J. Clin. Pharmacol. 40 (1991) 437-438.