The majority of people do not consume adequate (according to the RDA) amounts of magnesium from the food we eat. When it comes to our bodies, we are really referring to the magnesium ion (written Mg++) which has 2 positive charges (similar to calcium). On this page, you will learn

  • Role of Magnesium in our bodies
  • Why people supplement with magnesium (including how much)
  • Different forms of Magnesium supplement
  • How to maximize absorption of magnesium without interfering with calcium absorption

Role of Magnesium in our bodies

Magnesium plays many vital roles in the human body (as well as all life). We can view these roles at two levels:

  • the bodily functions (such as muscle contraction) that it regulates
  • at the molecular level - how it effects the function of the cells in our bodies

Bodily functions regulated by magnesium

  • Muscle and nerve support: Helps muscles relax after contracting and eases cramps.

  • Sleep and relaxation: Supports calming brain chemicals like GABA to promote rest.

  • Digestion: Relieves occasional constipation.

  • Blood sugar: helps move blood sugar out of your blood and into your muscles where the sugar can be used as fuel

  • Blood pressure: Assists in keeping glucose and blood pressure levels steady

  • Bone health: 50% to 60% of the total magnesium in the human body is found in bones. The magnesium is found on the surface of hydroxyapatite crystals in bone where it provides a structural role. It prevents the crystals from growing too large and becoming brittle. It also helps synthesize the collagen framework that calcium and phosphate bind to. As with calcium, it is also a reserve supply when serum levels dips too low.

Cellular/Molecular functions regulated by magnesium

  • as a cofactor in many enzymes (enzymes are proteins with catalytic activity, meaning they speed up chemical reactions). In fact, approximately 70% of the enzymes in the human body require magnesium for their activity
  • binding to ATP (adenosine triphosphate) - the small molecule which provides energy for the reactions occuring in our bodies. The binding of Mg stabilizes the ATP molecule and also neutralizes it so that it can interact efficiently with many enzymes. Similarly, Mg++ binds to GTP, CTP and UTP which also play roles in enzyme activity
  • structurally. It is part of our bones. Mg is part of the bone matrix. At the cellular level, it helps proteins to fold properly and helps our DNA and RNA to be in appropriate conformations.

Why people supplement with magnesium

There are two existing (and somewhat conflicting) goals for dietary magnesium.

Many people find it difficult to reach the RDA for magnesium by diet alone - hence the supplementation. Food processing such as refining grains strips away the nutrient rich germ and bran which contains much of the inherent magnesium. Some good dietary sources:

  • seeds and nuts
    • pumpkin seeds: 156 mg/ounce
    • chia seeds: 111 mg/ounce
    • almonds: 80 mg per ounce (but note they are also high in oxalates)
    • cashews: 74 mg per ounce
  • Vegetables and legumes
    • spinach: 78 mg per 1/2 cup of boiled spinach - but note extremely high oxalate content
    • black beans: 60 mg per 1/2 cup of cooked beans
    • edamame: 50 mg per 1/2 of cooked, shelled beans
    • baked potato: 43 mg for a 3/5 ounce potato
  • Whole grain
    • brown rice: 42 mg per 1/2 cup of cooked rice
    • plain yogurt (dairy): 42 mg per 8 ounces

Different forms of magnesium supplement

  • Magnesium (bis) Glycinate: highly absorbed. This supplement is mostly absorbed by intestinal receptors for amino acids and dipeptides (meaning 2 amino acids in a chain). It is absorbed at a higher efficiency than other forms, and most importantly, doesn't compete with calcium or iron for absorption. It is gently on the stomach and is used for sleep, anxiety and stress relief
  • Magnesium Citrate: Well abosrbed and frequently used to treat constipation due to its mild laxative effect. Need to be careful not to overdo it! The citrate can also inhibit kidney stone formation by competing with oxalate for calcium binding. Consult your physician if you are prone to kidney stones.
  • Magnesium Malate: easily absorbed. Said to provide energy support and ease muscle discomfort
  • Magnesium L-Threonate: able to cross the blood-brain barrier. It has been studies for possible benefits to cognitive health and memory
  • Magnesium Oxide: Poorly absorbed. Primarily used to treat indigestion, heartburn and constipation
  • Magnesium Sulfate: also known as Epsom salt. It is used topically in warm baths to soothe sore muscles. It does not provide systemic magnesium.
  • Magnesium Taurate: targetted toward hearth health and blood pressure

How to maximize absorption of both calcium and magnesium

Unless using magnesium glycinate or taking a minimal amount of calcium, try to separate magnesium and calcium by at least 2 hours so that receptors can regenerate. Since magnesium glycinate uses a different pathway for absorption (it is absorbed as an amino acid), it can be taken at the same time as calcium without compromising the absorption of either one.

Both magnesium and calcium absorption are diminished by the presence of phytates in your food. Unless specifically taking a supplement to help with sleep, spread the supplements throughout the day. Smaller quantities are absorbed more efficiently.

Digestive issues like celiac disease or chronic inflammation can decrease levels of absorption.

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