The Definitive Guide To Magnesium & Magnesium Supplements
Magnesium is the second most abundant mineral inside our cells and the second most common deficiency, next to Vitamin D.
Recently scientists have discovered the ‘Magnesome’, a protein encoding gene incorporating Magnesium, suggesting that the levels of Magnesium in the body may epigenetically alter the expression and behaviour of some of the proteins in our bodies, so altering the expression of health or disease of tissues.
These scientists concluded that “Presently we can annotate some 5% of the human genome as inheriting the capability of binding Magnesium ions.” (Piovesan et al. 2012)
0.05% of our body weight is Magnesium. (20-28gm). Magnesium is found naturally in dark leafy vegetables, beans, nuts, seeds and whole grains, all of which take their Magnesium from the soil. It is absorbed throughout the small intestine (Hardwick LL et al. 1991).
However, Magnesium is arguably one of the most depleted minerals in the soil. This is often attributed to:
- The use of herbicides and pesticides that kill off worms and bacteria in the soil. It is the bacteria in the soil that make it possible for plants to absorb minerals.
- Potash (potassium chloride or potassium carbonate) being used as a fertiliser. This is taken up by plants in preference to Calcium and Magnesium.
- Soil erosion as Magnesium is leached out by heavy rain.
- Acid rain (as occurs in air pollution) contains Nitric Acid. In the soil Nitric Acid reacts with Calcium and Magnesium to neutralise excess nitric acid. Eventually Calcium and Magnesium become depleted and the nitric acid reacts with Aluminium oxide in the soil. A reactive Aluminium builds up replacing Calcium and Magnesium in the plant. Calcium is needed for cell wall strength and Magnesium for chlorophyll for photosynthesis. So plants may grow taller and faster but are weak and lack chlorophyll.
- Food processing decreases Magnesium. It is lost in grains during milling and making of white flour. It is also lost from vegetables when they are boiled.
- Fluoride in water and toothpastes binds to Magnesium making it unavailable to the body. Fluoride is insoluble and replaces Magnesium in bone and cartilage.
- Stress. Increased stress results in decreased stomach acid and decreased hydrochloric acid in the stomach results in decreased absorption of Magnesium. Commonly consumed antacids neutralise Hydrochloric acid, decreasing Magnesium absorption.
- Magnesium absorption is altered by an unhealthy intestine for example; IBS, leaky gut, gluten and casein sensitivities, funguses & parasites, vitamin D deficiency and the formation of Magnesium soaps in the stools as Magnesium binds to unabsorbed fats.
- Some foods can block the absorption of Magnesium. High protein diets can decrease Magnesium absorption. Tannins in tea bind and remove minerals including Magnesium. Oxalic acid in rhubarb, spinach and chard and phytic acid in cereals and soy also block absorption of Magnesium.
- Junk foods, particularly sugary foods all use up extra Magnesium.
- Saturated and trans fats alter cell wall integrity, making it more rigid which affects receptor site function and prevents nutrients from getting into or out of the cell.
- Drugs – some drugs eliminate Magnesium. Antacids, antibiotics and diuretics all cause Magnesium depletion. Large consumption of caffeine and alcohol cause depletion with their diuretic effect.
- Hypokalaemia (low potassium levels) can increase urinary Magnesium loss.
- Body size – the larger the body, the larger the Magnesium pool, then the lower the absorption from any source.
60% of the body’s Magnesium is found in bones and teeth and the rest in muscle cells and body fluids with the highest concentration being in the heart and brain. The blood contains only 1% Magnesium.
The modern diet contains Calcium and Magnesium in the ratio of between 5:1 and 15: 1 compared to the “cave man” diet of 1:1. Too much calcium relative to Magnesium can result in constipation. Magnesium is needed for smooth muscle contraction and excessive calcium can interfere with this. Excessive calcium can lead to kidney stones, arteriosclerosis, dementia, asthma and decreased glucose uptake.
Magnesium is needed for 354 enzymes in the body. There are 3,751 Magnesium binding sites on human proteins.
What Do Magnesium Supplements Do?
Magnesium Supplments contribute to reduction of tiredness and fatigue and normal energy yielding metabolism.
Magnesium is present in every cell. ATP (Adenosine Triphosphate) is the major unit of energy produced in the body, but ATP is actually Magnesium–ATP. All enzymes that create or use ATP require Magnesium ions. Deficiency of Magnesium means that energy cannot be produced and tiredness and fatigue result.
Magnesium contributes to normal functioning of the nervous system for neurotransmission.
Magnesium acts as a calcium channel blocker and calcium metabolism regulator. It counteracts calcium at NDMA (glutamate) receptors. Activation of NDMA receptors results in the opening of an ion channel; Magnesium ions block the ion channel allowing the flow of sodium ions and small amounts of calcium ions into the cell and potassium out of the cell. Calcium flux is critical to synaptic plasticity, a cellular mechanism for memory and learning. Low levels of Magnesium result in hyper excitability of the nerves and random firing. This can alter sleep patterns making it difficult to get to sleep.
Researchers Starobrat-Hermelin & Kozielec (2004) have shown that children with ADHD (Attention Deficit Hyperactivity Disorder) showed improvement in hyperactivity with supplemental Magnesium.
Further research (Huss, Völp and Stauss-Grabo, 2010) found these benefits were enhanced further when supplementing with Omega 3 fatty acids.
Magnesium contributes to normal muscle function and muscle contraction including heart muscle.
35% of the body’s total Magnesium stores are stored in muscle. The part played by Magnesium in skeletal muscle is similar to that of nerves, acting as a calcium channel blocker, helping to regulate muscle contraction (Stephenson & Podolsky, 1977).
Studies at the University of Texas have shown that deficiency of Magnesium results in cramping and severe muscular pain such as occurs in Fibromyalgia.
(Russell et al 1995). When Magnesium malate was administered to patients with fibromyalgia, it was clinically demonstrated to improve pain and tenderness. Decreased levels of Magnesium in the blood have been related to heart arrhythmias and hypertension (Fox et al. 2001).
Magnesium contributes to normal protein synthesis.
Magnesium is needed for over 350 enzymes that are made of proteins. Magnesium is also required during DNA, RNA and protein synthesis. Magnesium is also required for the synthesis of glutathione (Swaminathan 2003)
Magnesium contributes to normal psychological function.
Depression has been demonstrated in people with low red blood cell Magnesium levels. (Nechifor. 2009).
Also if Magnesium is removed from the diet, anxiety and depressive like symptoms result. (Spasov, et al. 2008);
One particular review noted correlation between increased rates of depression and reduction in the diet of Magnesium. This reduction was by replacing whole grain bread with processed flour that had reduced Magnesium content. (Eby GB, Eby KL. 2010).
Magnesium supplementation also appears to be effective in reducing depressive symptoms, which are stress related.
Magnesium Contributes to the maintenance of normal bones and teeth
50% of the body’s Magnesium is found in bone. Magnesium is needed for the absorption, transport and metabolism of calcium, regulating parathyroid hormone that regulates bone breakdown and activating the enzyme required for the production of new bone. Studies have shown that Magnesium improved bone density. (Stendig-Lindberg & Tepper 1993).
Low levels of Magnesium in the blood and a low Magnesium:Calcium ratio have been associated with an increased risk of periodontal disease and poor tooth integrity (Meisel et al.2005).
Magnesium has a role in cell division
Low Magnesium levels are associated with increased oxidative stress and decreased cell proliferation. (Wolf, Trapani, et al. 2009).
After several months in incubation, human fibroblasts that were Magnesium depleted, exhibited characteristics of cells many times their age (Federica, Valentina Trapani, et al. 2008).
Magnesium is a common deficiency in type 2 diabetes at between 13.5% and 47.7% Magnesium has also demonstrated involvement in improvement of beta cell function in a double blind randomised study, concluding that Magnesium chloride improves the ability of beta cells to compensate for variations in insulin sensitivity (Guerrero-Romero, Rodríguez-Morán. 2011).
Basically they do not have enough Magnesium to manage getting glucose into the cell efficiently.
Magnesium contributes to electrolyte balance
Electrolytes are minerals in the body that have an electrical charge. Calcium, Magnesium, Sodium, Potassium, Chlorine and phosphate are all electrolytes. Levels of electrolytes can become too low due to sweating, vomiting, diarrhoea or even over hydration.
Deficiency of Magnesium can impair the sodium potassium ATPase pump and calcium-blocking activity is impaired by insufficient Magnesium leading to membrane destabilisation and hyperexcitibility (E L Tso and R A Barish. 1992).
Bioavilabilty Of Different Magnesium supplements
All Magnesium supplements are a combination of Magnesium with another substance such as a salt. Every salt provides different amounts of elemental Magnesium. The amount of Magnesium and its bioavailability alter the effectiveness of the supplement. Other factors affecting absorption of Magnesium are the existing Magnesium levels of the individual, as Magnesium will be less rapidly absorbed if body levels are already adequate and excreted through the urine or stools if given in excess. Also all the points mentioned above will have an influence on Magnesium absorption.
Bioavailability refers to the amount of elemental Magnesium actually absorbed by the body.
In short, the amount of Magnesium that your tissues can use readily is based on how soluble the Magnesium product is and the amount of elemental or ionic Magnesium that is released.
A value called the “stability constant” is based on the metal-ligand complex. Stability constants are a measure of the strength of the bonds of the compound molecule and vary from 0 upwards.
The lower the stability constant, the more easily it dissolves or dissociates into its metal ions due to weak ionic bonds). This means the body can easily absorb the metal in ionic form in a pH from 2 (stomach acid) to 7.4 (serum and lymph) ( Thomas E. Furia. 1972).
Metal ions easily pass between the cells. They are under the control of gravity, moving body fluids and the electric charge of the cell membrane. Metal ions may react with the cell membranes or be taken into the cell. Magnesium ions are present in much greater concentration inside cells than in the serum, being actively brought into the cell, as the cell needs them.
So although Magnesium oxidehas the highest elemental Magnesium (60%), it also has a high stability constant, meaning that it does not dissociate, or ionize and is therefore poorly bioavailable Gut absorption is believed to be as low as 4%( leaving 288mg of a 500mg capsule unabsorbed in the intestines).
You will find that Magnesium oxide is very common in poor quality supplements simply because it is cheap however, only about 4% of its elemental magnesium is absorbed, equivalent to about 12 mg out of a 500 mg tablet.
Magnesium Chloride Supplements.
Magnesium chloride (12% elemental Magnesium) has a stability constant of 0 and is completely ionized across a large pH range, 2 (found in stomach acid) to 7.4 found in extracellular tissues such as blood and lymph. Magnesium chloride has the chloride part of its compound to produce hydrochloric acid in the stomach and enhance its absorption. This is particularly suitable for anybody with low stomach acid.
Magnesium Malate Supplements
Magnesium malate (6.5% elemental Magnesium) has a stability constant of 1.55 and is nearly completely ionisable. Again the weak ionic bonds of Magnesium and malic acid are easily broken making it readily soluble in the body.
Magnesium Citrate Supplements
Magnesium citrate (16% bioavailability) and stability constant of 2.8. Weak bonds provide a high bioavailability. Magnesium citrate works by attracting water through the tissues by osmosis. When the Magnesium citrate reaches the small intestine it attracts enough water to induce defecation. The extra water helps create more faeces, stimulating bowel motility and may have a mild laxative effect. This form of Magnesium functions best on an empty stomach followed by a full glass of water or juice to aid absorption.
Researchers have demonstrated that Magnesium bioavailability is greater in citrate than oxide taking the pH of stomach acid and alkalinity of pancreas into consideration. (Lindberg, Zobitz et al. 1990)
Magnesium sulphate Supplements
Magnesium sulphate (10% elemental Magnesium) is also known as Epsom salts. It contains Magnesium; Sulphur and Oxygen. It is the main preparation of intravenous Magnesium. Bioavailability is limited and variable with degrees of mild diarrhoea. (Morris, LeRoy et al. 1987).
Magnesium Ascorbate Supplements
Magnesium Ascorbate (6.4% elemental Magnesium) is a source of both vitamin C and Magnesium. It is a neutral salt having a significantly higher gastrointestinal tolerance than some of the other forms.
Magnesium Phosphate Supplements
Magnesium (19% elemental Magnesium) but practically insoluble in water. Magnesium is bound to phosphate in teeth and bone.
Magnesium Carbonate Supplements
Magnesium Carbonate (42% elemental Magnesium). Research sources suggests different bioavailability rates between 5-30%. In large doses this form may have a mild laxative effect. Magnesium carbonate reacts with hydrochloric stomach acid to form Magnesium chloride. This conversion is dependent on adequate stomach acid levels.
Magnesium Hydroxide Supplements
At 41.67%, Magnesium Hydroxide has a relatively high percentage of elemental magnesium but has a low solubility in water, suggesting poor absorption. When in a suspension in water it is often called milk of magnesia, used as an antacid or laxative.
Although a high percentage of elemental Magnesium, the Magnesium ion is very poorly absorbed from the intestinal tract, drawing water from the surrounding tissues by osmosis.
Interestingly research done in Magnesium depleted rats using 10 organic and inorganic Magnesium salts using a stable isotope approach concluded that all salts were equally efficient in restoring blood and plasma Magnesium levels. (Coudray, Rambeau. 2005).
This has not been repeated in humans who are more complex in terms of having other factors that influence absorption.
What are the Symptoms of Magnesium Deficiency?
The following include some of the symptoms commonly associated with Magnesium deficiency. If you experience any of these symptoms you should consult a health care practitioner.
Mild Deficiency
- Loss of appetite
- Headache
- Unable to think clearly
- Nausea and vomiting
- Fatigue and weakness
Severe Deficiency
- Abnormal heart rhythms, palpitations
- Muscle cramps or contractions
- Fibromyalgia
- Numbness and tingling  
Edit
Thanks for all the comments, regarding Telea’s comment: “I notice you do not make any mention of Chelated Magnesium”, Magnesium Chelate is a product we now manufactruing in the form of Magnesium Bisglycinate.
Calcium, magnesium, iron, zinc, selenium, chromium and manganese absorption are all affected by phytates (found in cereals and nuts) which are dietary ligands or bonds that bind to the mineral making it harder for the mineral to free itself when absorption is imminent. This is why it is better to take these minerals away from phytate and oxalate containing foods to maximise absorption, what ever is the preferred form.
Amino acid chelates such as Magnesium bisglycinate, bind the magnesium and the glycine together protecting the Magnesium from making stronger attachments to other binding agents such as phytates. It is believed that this weaker binding energy allows the magnesium to disassociate from the double glycine attachment when absorption is about to occur.
To date I cannot find any scientific studies relating to the absorption and nutritional value of amino acid chelates, except on one – Ferrochel, the Albion patented amino acid complex that you mention. These studies compared absorption with ferrous sulphate and were carried out by mixing the iron compounds with different foods, in order to test the value of the compounds as ingredients of fortified grain products and infant formulas.
The published research showed Ferrochel absorption to be twice that of ferrous sulphate when given to iron deficient adults in bread (Pineda, 2003), and 4x better absorbed when given to adult males in cornmeal porridge, although this appeared to be contentious (Hallberg & Hulthén 2000). No difference was found between Iron bisglycinate and Iron sulphate absorption in 9 month old weaning infants (Fox, Eagles et al. 1998).
It appears that the evidence of improved absorption of mineral acid chelates occurs when the mineral compounds are taken with foods containing absorption inhibitors such as phytates and oxalates. This problem can be resolved by taking mineral supplements away from these foods. Unfortunately there is no published research on absorption involving tablets or capsules of chelates (in this case iron bisglycinate) taken away from meals.
However, all this said, I think Magnesium bisglycinate is an excellent capsule supplement, especially as most people take supplements with breakfast which may contain phytate containing foods. I am looking in to producing this as part of our range of Magnesium products. Incidentally we already do supply Zinc bisglycinate for this reason in our Zinc Formula, designed for long term zinc supplementation.
References
Piovesan, D., Profiti, G., Martelli, P. L., Casadio, R., 2012. The Human “Magnesome”: Detecting Magnesium Binding Sites on Human Proteins. BMC Bioinformatics. 13(14):S10 Hardwick, L.L, Jones, M.R, Brautbar, N, Lee, D.B 1991. Magnesium Absorption: Mechanisms And The Influence of Vitamin D, Calcium and Phosphate. The Journal of Nutrition. 121(1), p.14.
Starobrat-Hermelin, B., Kozielec T., 1997. The effects of Magnesium physiological supplementation on hyperactivity in children with attention deficit hyperactivity disorder (ADHD). Positive response to Magnesium oral loading test. Magnesium Research. 10(2). pp.149-56.
Huss, M., Völp, A., Stauss-Grabo, M., 2010. Supplementation of Polyunsaturated Fatty Acids, Magnesium and Zinc in Children Seeking Medical Advice for Attention-Deficit/Hyperactivity Problems – An Observational Cohort Study. Lipids in Health and Disease. 9(105).
Stephenson, E.W., Podolsky, R.J., 1977. Regulation by Magnesium of Intracellular Calcium Movement in Skinned Muscle Fibers. Journal of General Physiology. 69(1). pp.1-16.
Nechifor M. 2009. Magnesium in major depression. Magnesium research: official organ of the International Society for the Development of Research on Magnesium.22(3).
Spasov AA, Iezhitsa IN, Kharitonova MV, Kravchenko MS. 2008. Depression-like and anxiety-related behaviour of rats fed with Magnesium-deficient diets. Zh Vyssh Nerv Deiat Im I P Pavlova.58(4):476-85.
Eby GA 3rd, Eby KL. 2010. Magnesium for treatment-resistant depression: a review and hypothesis. Medical Hypotheses. 74(4):649-60.
Stendig-Lindberg G, Tepper R, Leichter I. 1993. Trabecular bone density in a two year controlled trial of peroral Magnesium in osteoporosis. Magnesium research: official organ of the International Society for the Development of Research on Magnesium. 6(2):155-63.
Meisel P, Schwahn C, et al. (2005). Magnesium deficiency is associated with periodontal disease. Journal of dental research. 84 (10): 937-41.
Wolf FI, Trapani V, Simonacci M, Boninsegna A, Mazur A, Maier JA. 2009. Magnesium deficiency affects mammary epithelial cell proliferation: involvement of oxidative stress. Nutrition and Cancer. 61(1):131-6.
Federica I Wolf, Valentina Trapani, Achille Cittadini. 2008. Magnesium and the control of cell proliferation: looking for a needle in a haystack. Magnesium Research. 21(2):83-91.
Guerrero-Romero F, Rodríguez-Morán M. 2011. Magnesium improves the beta-cell function to compensate variation of insulin sensitivity: double-blind, randomized clinical trial. European journal of clinical investigation. 41(4):405-10.
E L Tso and R A Barish. 1992. Magnesium: clinical considerations. The Journal of Emergency Medicine. 10(6):735.
Thomas E. Furia. 1972. Handbook of Food Additives. Second Edition. Palo Alto, California. CRC Press.
Lindberg JS, Zobitz MM, Poindexter JR, Pak CY. 1990. Magnesium bioavailability from Magnesium citrate and Magnesium oxide. Journal of the American college of nutrition. 9(1):48-55.
Morris ME, LeRoy S, Sutton SC. 1987. Absorption of Magnesium from orally administered Magnesium sulfate in man.Journal of toxicology. Clinical toxicology. 25(5):371-82.
C Coudray, M Rambeau, C Feillet-Coudray, E Gueux, JC Tressol, A Mazur, Y Rayssiguier. 2005. Study of Magnesium bioavailability from ten organic and inorganic Mg salts in Mg-depleted rats using a stable isotope approach. Magnesium Research. 18(4):215-23.
Russell, IJ., Michalek, JE., Flechas, JD., Abraham, GE. 1995. Treatment of fibromyalgia syndrome with Super Malic: a randomized, double blind, placebo controlled, crossover pilot study. The Journal of Rheumatology.22(5).
Fox, C., Ramsoomair, D., Carter, C. 2001. Magnesium: its proven and potential clinical significance. Southern Medical Journal.94(12).
Mathers, TW., Beckstrand, RL. 2009. Oral Magnesium supplementation in adults with coronary heart disease or coronary heart disease risk. Journal of The American Academy of Nurse Practitioners.21(12).
Swaminathan, R. 2009. Magnesium Metabolism and its Disorders. The Clinical Biochemist Reviews.24(2).
Oscar Pinead. 2003. Iron bis-glycine chelate competes for the nonheme-iron absorption pathway. American Society for Clinical Nutrition. vol.78 no.3 495-496.
Leif Hallberg and Lena Hulthén. 2000. No advantage of using ferrous bisglycinate as an iron fortificant. American Society for Clinical Nutrition. Vol.72 no.6 1592-1593.
Tom E Fox, John Eagles, and Susan J Fairweather-Tait. 1998. Bioavailability of iron glycine as a fortificant in infant foods. American Journal of Clinical Nutrition. 67:664-8.