I wrote here on the difference between a vitamin and a mineral – while vitamins are more complex molecules, minerals are single elements on the periodic table, almost always bound to something else for the purpose of delivery.  Magnesium is a mineral, and it’s a critical one.  Here’s why.

Magnesium is a cofactor for about 300 reactions in your body (meaning it’s required for the reaction to proceed).  These include making, transporting, and using energy, making DNA and proteins (and all of your body tissues are made of proteins, so this is a big one), controlling nerve signals, relaxing muscles, and responding adequately to stress.

Reasons You Might Be Low

  1. You might not be eating enough of the foods that contain magnesium.  Magnesium is found in whole grains, nuts, beans, green leafy veggies, fish, and (clean) meat.  But few of us consume primarily whole foods these days – much of what passes for food has been so processed that it contains little to no nutritional value.  (Here’s a good overview of how you should be eating, compared to some of the fad diets out there).
  2. Even if you’re consuming plenty of these foods, a bunch of pharmaceuticals also block the absorption of magnesium or increase its excretion, including laxatives, diuretics, proton pump inhibitors (like Nexium), antibiotics, colchicine, and corticosteroids (like prednisone).
  3. You can also deplete magnesium by consuming too much alcohol or too many phosphates (from soda!)
  4. If you have a hard time absorbing nutrients in general (a malabsorption syndrome, such as Crohn’s, celiac sprue, or enteritis), then you are likely to be deficient also.
  5. You might be deficient if you have Type 2 Diabetes, especially if it isn’t well controlled, because high blood sugar leads to increased urination, and magnesium reabsorption happens in the kidneys.

How You Know If You’re Low

The test for magnesium in your bloodstream (serum magnesium) isn’t reliable, because most magnesium stays inside your cells and your bones.  Red blood cell (rbc) magnesium is a better test, because that’s testing the magnesium concentration inside the red blood cells.

However, often clinical signs and symptoms (below), combined with knowledge of one of the five causes listed above is the best way to determine deficiency.  Low magnesium can lead to:

  • Problems with memory and concentration
  • Depression and apathy
  • Emotional lability (you get upset easily)
  • Irritability, nervousness, and anxiety
  • Insomnia
  • Constipation (magnesium is the active ingredient in many laxatives)
  • Migraines
  • PMS and cramping
  • Fibromyalgia and muscle pain
  • Fatigue
  • ADHD

What to Do About It

If you’re not getting enough from your diet, drinking too much alcohol or too much soda, the solution is obvious. 🙂

If you have a malabsorption syndrome, the solution is of course to address the underlying cause.  Or if you have Type 2 Diabetes, the solution is to regulate your blood sugar adequately.

If you’re on magnesium-wasting drugs, the question becomes whether you really need them.  In many cases, it’s possible to correct the underlying issue and render the need for the drug superfluous.  If this isn’t possible or practical, supplementation becomes appropriate.  Make sure you get an absorbable form, though – the most common magnesium supplements are complexed with carbonate, chloride, and oxide, which are not well absorbed.  You want to look instead for magnesium citrate, taurate, orotate, or a chelated combination.