ADVERTORIAL
The compound form of magnesium – a critical determinant of bioavailability
by Samuel Peters | BHSc ( Naturopathy )
Magnesium deficiency is an increasing concern
Maintenance of magnesium sufficiency requires a dietary intake of 320mg for women and 420mg for men . Numerous studies from around the world have found that many individuals do not reach these recommended intakes , often only reaching two-thirds of this minimum target . 1
Whilst the typical western diet may provide enough magnesium to avoid a frank deficiency , it is unlikely to provide the levels required to maintain optimal magnesium levels . Recent evidence suggests that the current recommended daily allowance ( between 300 and 420mg / day ) is insufficient to provide optimal health and longevity and that many individuals require an additional 300mg per day in order to lower their risk of chronic disease , which may require the use of additional supplements . 1
There is a growing body of literature which suggests that subclinical magnesium deficiency is one of the leading causes of chronic diseases and should now be considered a public health crisis . 1
Choosing superior magnesium forms
The compound form of magnesium is an important factor that affects the efficiency of absorption . Magnesium can be chemically classed as either organic or inorganic magnesium . Inorganic forms of magnesium found as salts , metals , minerals and other carbon-free forms ( such as chloride , oxide and sulphate ) are generally more poorly absorbed in the gastrointestinal tract when compared to organic forms such as magnesium citrate and magnesium glycinate . 2
Although consensus has yet to be reached , numerous clinical studies have found that the organic forms of magnesium show the highest rate of bioaccessibility ( dissolution and availability of the active drug in the digestive tract ), and bioavailability ( proportion of the active drug that reaches systemic circulation ), compared with inorganic magnesium salts . 3
Clinical studies
Urinary magnesium excretion immediately following supplementation is thought to represent a reliable clinical marker of magnesium bioavailability where increased urinary excretion likely represents increased intestinal absorption and systemic bioavailability . In a randomised , double-blind study , both magnesium citrate and magnesium amino acid chelate were found to be more bioavailable than magnesium oxide , exhibiting significantly greater 24 hour urinary magnesium excretion . In addition , magnesium citrate significantly increased salivary magnesium concentration whereas no change was observed with magnesium oxide supplementation . 4 These findings have been confirmed by more recent studies which have found that magnesium citrate increases both serum levels and urinary excretion of magnesium over a 24 hour period , compared to magnesium oxide . 5
In another clinical study , magnesium citrate was found to equally increase plasma magnesium levels when compared to magnesium oxide , however intracellular ionic magnesium was significantly higher in leukocytes of the individuals supplemented with magnesium citrate . 6 , 7
Recent preclinical research also suggests that magnesium citrate is able to dosedependently increase blood , brain and muscle tissue magnesium concentrations , with magnesium glycinate effectively increasing brain and blood magnesium concentrations . 2
Gastric acid secretion and magnesium absorption
Experimental studies demonstrate that magnesium citrate has a much greater dissolution and solubility under a wide variety of gastrointestinal conditions . In a simulation of various concentrations of gastric acid secretion , magnesium citrate was found to have a significantly greater solubility compared with magnesium oxide at all concentrations . Importantly , at a concentration of complete acid inhibition ( resembling a state of achlorhydria ), whilst magnesium oxide was virtually insoluble ( 0.8 % magnesium recovery ), magnesium citrate was still highly soluble ( 55 % magnesium recovery ). 8 This finding may be of significance for individuals with impaired gastric acid secretion ( such as the eldery , anxious or medicated patient ) as most magnesium is thought to be absorbed as an ion ( Mg2 +) through the GIT . Therefore the solubility of the compound form of magnesium appears to be an important precondition for absorption , with increased solubility correlating with increased absorption . 9 , 10
For further clinical support , see BioMedica ’ s technical sheet ‘ Assessing magnesium forms for optimal clinical outcomes ’ at biomedica . com . au
References available on request
Disclaimer : The views and opinions expressed in these advertorials are those of the authors and do not necessarily reflect the opinions of ATMS or its Directors .
54 | vol29 | no1 | JATMS