On Magnesium

Posted by on May 15, 2013 in Supplement Shelf


 Magnesium Crystals

(Photo – Creative commons license by Warut Roonguthai)

Magnesium is a metallic (alkali earth)  element and one of the most important mineral micronutrients  in our bodies. It plays a vital role  as a cofactor in many critical metabolic processes in our physiology, especially related to energy metabolism as well as protein and nucleic acid synthesis.   Every cell in our body requires magnesium. One of my mentors used to say that “magnesium is the bringer of light”. This partly refers to its role in plants is found at the heart of the chlorophyll molecule, rather like iron is at the heart of heme (oglobin) in animals. I like to add that it is yin to Calcium’s yang, it is calming, and relaxing as opposed to excitatory and stimulating like calcium. Magnesium’s role was extensively researched, and some might say discovered, by Dr Mildred Seelig, who published tens of dozens of reseach papers and several popular books on magnesium before her death in 2005.

Dr Mildred Seelig

mildred seelig

 (photo ©  J.AM.Coll. Nutr)

Magnesium’s role was extensively researched, and some might even say discovered, by Dr Mildred Seelig, who published tens of dozens of reseach papers and several popular books on magnesium before her death in 2005.  Over 40 years, Seelig unravelled the role of magnesium in cardiac, renal and skeletal disease, and her name is inseperable from our current understanding of the material.

Forms of Magnesium

Traditional Epsom Salts are Magnesium sulfate, this is also the form used when Magnesium is given as an IV. In modern nutritional therapeutics, there is a strong preference for covalent or chelated forms of magnesium as opposed to the “inorganic” forms such a Magnesium Carbonate or  Magnesium  oxide.

Orally,  Magnesium is taken as a powder or a capsule. For nerve related issues, Mg Glycinate is favored, and is available as powder. For cardiovascular issues, Mag Taurate is often preferred, and is available in capsules. Other  salts of magnesium are available, such as Magnesium citrate or malate;  in our practice we tend to use glycinate or taurate. Another powder form is Buffered Vitamin C as magnesium ascorbate. This is especially useful if magnesium is also being employed as a “stool softener” because both Vitamin C and Magnesium orally can lead to bowel loosening; both C and magnesium are important micronutrients so this is a great form of first line laxative eg for opioid induced constipation.

A recent development is “magnesium oil” – a liquid preparation for topical application to the skin. This is not a real “oil” but an anhydrous Magnesium chloride which deliquesces (absorbs moisture) to form a thick viscous liquid. This is usually dissolved in Magnesium sulfate, and then sold as Magnesium oil for skin use. It is good for cramps, (Charly horse type) and also for absorbing more extra  magnesium if bowel tolerance becomes a dose limiting issue because dermal absorption bypasses the GI system.


There is no standard dose level for magnesium. Daily requirements for normal healthy adults range from 300+-400+ mg (female lower than male).  Dietary sources are primarily dark green leafy vegetables and nuts, as well as legumes, avocados and some fruits like apricots and bananas. Supplemental levels  should be based on therapeutic intention, but range from 350-1000mg per day in divided doses to reduce the risk of bowel intolerance (unless that is actually a desired side effect!). Magnesium, when taken for bone support should be in a 1:1 ratio with Calcium rather than 1:2 which is the common commercial preparation. Magnesium  helps calcium absorption!  True deficiency is not  common, however chronic insufficiency is very common, especially in green vegetable poor diets such as the S.A.D (standard American). Also, as we age, our  kidneys whose job is to retain vital  electrolytes, become less efficient which leads to a chronic  renal “wasting” of magnesium.


Testing Magnesium Levels

Our body magnesium levels are important for many reasons, but testing them is not so simple.  Although serum magnesium is sometimes checked in bloodwork (it is not part of a regular metabolic panel) the serum values are  inaccurate representations of cellular levels of Mg: – less than 1% of magnesium is in the blood. Recently , there have been intracellular tests for magnesium developed using  buccal tissue samples – these are very  accurate indicators. An example is the EXA test from Intracellular diagnostics Inc in Oregon. Old school clinicians might remember Chovstek’s Sign – a physical diagnostic test for latent tetany which actually, if positive, is a good indicator of deficient magnesium levels.


 21st Century magnesium “oil”  supplement – Magnagel by Designs For Health – Contrasted to top photo- vapor deposited magnesium crystals