Supplements After 50: Magnesium

Almonds contain magnesium

This article is part of a series called “Supplements After 50”. The first two posts are here and here.

Magnesium is a recent addition to my supplement regimen. If you’re like me, you mindlessly take a daily multi-vitamin, expecting that your “recommended daily allowances” are in that horse pill. Just like we discovered with vitamin D, if you’re over 50, you may not be getting all the magnesium you need, even in one of those “Silver” multi-vitamins.

Why Take Magnesium?

I had heard lots of folks online talk about magnesium (and you know everything you read on the Internet is true!). But it wasn’t until my chiropractor suggested I take it that I took it seriously. At the time I was recovering from a particularly nasty shoulder injury after a tough week of rugby. My muscles were in knots, and we were trying to get them to release some of the tension they were holding. That’s when he suggested I take a supplement. As it turns out, magnesium plays a major role in muscle function, including its ability to contract and relax. Theoretically, then, supplementing an deficient athlete’s magnesium intake could affect performance and recovery.

Magnesium plays a role in plenty of bodily functions, but here are some reasons why I take it:

  • Exercise recovery – A 2006 study[1] stated “Magnesium supplementation or increased dietary intake of magnesium will have beneficial effects on exercise performance in magnesium-deficient individuals”. See comments, above.
  • Better sleep – I struggle with sleep quality, and have for years. Although the reasons aren’t entirely known, magnesium improves several indicators of good sleep. A double-blind, placebo-controlled study (the gold standard) in 2012 by the Faculty of Nutrition and Food Technology, Tehran, Iran [2] concluded that supplementation improved “sleep efficiency, sleep time and sleep onset latency, early morning awakening, and likewise, insomnia objective measures such as concentration of serum renin, melatonin, and serum cortisol, in elderly people”.
  • Increased testosterone – I’ve mentioned this in previous posts, but testosterone production decreases in men as they age. Yet it’s one of those elements that makes men – well – men! Although many of my peers have decided to start hormone therapy, I’m holding off as long as possible. Magnesium seems to affect testosterone levels. A 2010 study “show[ed] that supplementation with magnesium increases free and total testosterone values in sedentary and in athletes”[3]. Add that to my regimen!
  • Insulin sensitivity – Again, I’ve written about this before. In a family where both sides are passing me an inclination towards diabetes, I’ll try anything to stave it off as long as I can. A randomized double-blind study by the Medical Research Unit in Clinical Epidemiology in Mexico determined that insulin sensitivity was improved with oral magnesium supplementation.[4]
  • Other – Other conditions magnesium is known for improving include inflammation (in adults older than 51), depression (especially in younger adults), and bone health (by increasing the efficiency of calcium uptake).

Update (September 21, 2018) The journal Open Heart published a very long and detailed report on hypomagnesemia (low magnesium) in its January 13, 2018 issue. It goes far beyond what I can cover. Download the PDF here.

Natural Sources of Magnesium

First of all, let me say that before trying to supplement with magnesium that you should consult your doctor. As always in life, too much of a good thing can turn out to be bad.

The US RDA for magnesium is 420 mg/day for men 31 years old and up.

Natural sources of magnesium include green, leafy vegetables (like spinach or chard), nuts (a cup of sliced almonds has around 250 mg), yogurt or kefir, and black beans.

My Experience

If you go the oral supplementation route, you have several choices, but let me share my experience in hunting down the best I could find and afford.

Off the shelf at your local grocery or pharmacy you’ll find two main magnesium supplements available: magnesium citrate and magnesium oxide. I had a terrible time tolerating these. If you don’t recognize it, magnesium citrate is the stuff you get before having a colonoscopy. It induces explosive diarrhea. Most people don’t want that.

Magnesium oxide is better absorbed by your body than magnesium citrate, but it’s still not an incredibly efficient source of magnesium. In addition, I still had considerable stomach issues taking it. It’s probably the cheapest magnesium supplement on the shelf, however, so some people may opt for this based on price.

I finally landed on magnesium glycinate. Because of the way the magnesium is combined with the amino acid glycinate, it is easily absorbed and also gentle on the stomach. However, it’s also the most expensive formulation I found. My first batch was from Metagenics ($25.95 for 120 100 mg tablets). I am now testing Doctor’s Best High Absorption Magnesium (Amazon affiliate link). It’s a little different formulation, but is still easy on my stomach at this point, and it’s a bit less expensive than the Metagenics ($14.60 for 240 200 mg tablets).

Are you taking a magnesium supplement? Why? Which one? Chime in below and let us know.


[1] “Update on the relationship between magnesium and exercise”,
[2] “The effect of magnesium supplementation on primary insomnia in elderly: A double-blind placebo-controlled clinical trial”,
[3] “Effects of Magnesium Supplementation on Testosterone Levels of Athletes and Sedentary Subjects at Rest and after Exhaustion”,
[4] “Oral Magnesium Supplementation Improves Insulin Sensitivity and Metabolic Control in Type 2 Diabetic Subjects”,

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