Magnesium and arrhythmia

Because magnesium is removed during municipal water treatment and is absent from most bottled water, deficiency of this crucial mineral is a growing problem.

Magnesium deficiency can manifest itself in a wide variety of ways, from muscle cramps (usually calves, toes, and fingers), erratic blood sugars, higher blood pressure, to heart rhythm problems. The abnormal heart rhythms that can arise due to magnesium deficiency include premature atrial contractions, premature ventricular contractions, multifocal atrial tachycardia, atrial fibrillation, and even ventricular tachycardia, fibrillation, and Torsade de Pointes (all potentially fatal). Magnesium is important!

Magnesium supplementation is therefore necessary for just about everybody to maintain normal tissue levels. (The exception is people with kidney disorders, who should not take magnesium without supervision, since they retain magnesium.)

Here is a Heart Scan Blog reader's dramatic rhythm-correcting response to magnesium supplementation:

Dr. Davis,

A few months ago, I contacted you inquiring if you had written any articles on arrhythmia. You were generous enough to answer and guide me to an LEF article you'd written in which you stressed fish oil and magnesium. I had been suffering with bad PVCs [premature ventricular contractions] for over 20 years, and they had gotten so bad recently that I was told my next options were ablation or pacemaker!

I was already on fish oil and had not seen any difference, and so I researched the magnesium you suggested more thoroughly and found a huge body of studies supportng its effect on arrhythmia. I also read many posts on heart forums with people having success with it. After getting advice from various bloggers, I tried magnesium taurate in the morning and Natural Calm (an ionized form of mag citrate) in the afternoon and evening. Within three days the PVCs were quite diminished and by 2 weeks totally gone! As long as I keep taking it, they never return---not even one irregular blip---even when I drink strong coffee! The magnesium also cleared up my restless leg syndrome, my eye twitching, and insomnia. (Apparently, I was the poster-girl for magnesium deficiency.)

I am so angry that after all these years of suffering, trying various medications, and seeing at least 4 different cardiologists that NOT ONE ever even mentioned trying magnesium. The generosity of the few minutes you took to answer my email and steer me in a helpful direction brought me total relief.

Thank you SO MUCH!

Catherine C.

Comments (35) -

  • Emily

    2/11/2010 4:17:58 PM |

    are there not food sources of magnesium that are bio-available as well as the option of supplementing?

  • Mike

    2/11/2010 4:33:25 PM |

    I'll echo my thoughts on magnesium's anti-arrythmic properties; in my early 20's, I found I had intermittent episodes of frequent multi-focal PVC (premature ventricular contractions), exacerbated by stress and caffeine.  I saw a cardiologist for this, and had no subsequent treatment or follow up.

    In my 30's, I started supplementing with ZMA (zinc, magnesium and B6) to improve athletic recovery; I  noticed a nice, regular sinus rhythm on the cardiac monitor (I work as a firefighter/paramedic).  

    I have no doubt that a vast majority of people, especially athletes, are deficient in magnesium.  One of thee most important minerals!  Even with a solid diet, Mg is hard to come by, and excretion is enhanced through physical activity and sweating.  I like ZMA personally, but I have heard good things about Natural Calm.

  • davide

    2/11/2010 5:48:23 PM |

    ...three other very common results of magnesium deficiencies:

    1. Constipation
    2. Headaches
    3. Muscle tension/cramps

    I say this from first hand experience. I will not go a day without it. But it is important to use the right kind of magnesium. Magnesium oxide is the least preferred.

  • TedHutchinson

    2/11/2010 6:02:55 PM |

    68% of USA adults don't reach the current RDA intake for magnesium and most people who understand the issue would say, like the RDA for Vitamin D, the current magnesium RDA is woefully inadequate.
    KRISPIN has a useful  
    Formula to Calculate Magnesium Daily Requirement-  5 to 10 milligrams per day per kilo of ideal body weight or 2.5 to 4.5 milligrams per day per pound of ideal body weight.  

    Example: 70 kilos or 150 pounds= 350 mg. to 700 mg. daily.  

    Magnesium is an incredibly safe mineral to supplement with and too much magnesium passes into the colon where it's hygroscopic properties means it attracts water and the result is loose stools. So you will be made aware when you have taken too much magnesium.
    Fellow misers may want to consider DEAD SEA SALTS magnesium chloride available in 25kg sacks from Equine  suppliers, Country Traders, suppliers to small farmers and livestock merchants. In the UK its pretty cheap £7ish a bag. Epsom Salts works as well if not better if you have arthritis. (Think Health Spa) but may be twice the price.Here's how to use it The advantage of having a soak in  magnesium rich bath water is your body won't absorb more than it needs transdermally.
    Do take note of the fact that magnesium calms nerves and relaxes muscle fibers.
    Soaking in a hot bath enriched with magnesium chloride (Dead Sea salts or magnesium sulphate (Epsom Salts) will leave you ready for bed and a good nights sleep. So later in the day, rather than morning.
    Lots of good magnesium info here MGWATER

    Don't try telling anyone on Diabetes forums of the relationship of magnesium to diabetes it's almost as provocative as trying to explain the Vitamin D Diabetes interrelation and will surely see you banned.

  • Anonymous

    2/11/2010 6:24:34 PM |

    The onset of PVC's in my mid-40's occurred about the same time as the onset of blindlingly painful nocturnal leg cramps of the calves and thighs.

    God only knows how many tests were ordered by the cardiologist I saw, or the other doctors that followed.  A lot of tests, not much to show for it except the threat of a statin prescription, a prescription for a "heart healthy" diet, a la the American Heart Association, and a pat on the head or two.

    Relief came several years later in the form of daily supplementation with magnesium glycinate ordered by a physician, whose practice is devoted to wellness... not sickness.


  • DancinPete

    2/11/2010 8:46:11 PM |

    Is there an easy/cheap way to find out if you're magnesium deficient without getting a blood test?

  • TedHutchinson

    2/11/2010 11:25:51 PM |

    @ DancinPete
    Is there an easy/cheap way to find out if you're magnesium deficient without getting a blood test?

    Magnesium supplementation is so cheap and safe it's probably worth assuming you are deficient, take an effective amount, and if or when you start to get loose stools, back down a bit so you don't have that problem.

    Least well absorbed form is magnesium oxide.

    I use magnesium malate but magnesium citrate is fine for those who need the laxative properties.

  • Anonymous

    2/11/2010 11:40:11 PM |

    On a  very low-carb diet with little vegetables and no fruit, is it important to supplement potassium as well as magnesium?  If so, how much potassium?

  • polyhex

    2/12/2010 12:10:33 AM |

    I have seen the same thing in myself.  

    I had leg cramps in pregnancy which I stopped cold with magnesium.  An unanticipated side effect was the total resolution of a minor but persistent arrhythmia.  Recently I was lax in taking the supplements and my arrhythmia came back, exacerbated by exhaustion (new baby) and caffeine (new baby.)  I started the magnesium again and it's gone!

  • Chloe

    2/12/2010 12:57:06 AM |

    On magnesium and calcium from my experience:  I increased my D3 supplementation (boosted 7 reading to 98, GrassRoots Health testing), but started to experience very high "fluttery" pulse, 140+ and I am in my 60s.  OMG how bad I felt.  Practically everywhere I searched said up the magnesium.  I did (magnesium taurate) but this problem continued.  I then changed on the following page and it has saved me:

    Calcium citrate powder in water with a little bit of vitamin C powder (read calcium better absorbed in acidic environment) would bring my pulse and blood pressure down within 30 minutes.  

    Since I am without health insurance or the means to see a doctor anyway, I can only deal with the symptoms and not know the official diagnosis.

    My pulse was high, weak, and "fluttery."  Now that I supplement with 2000 mg of calcium citrate and 1000 mg of magnesium taurate my heart problems have disappeared.

  • Mike

    2/12/2010 3:27:33 AM |

    Nice posts, Ted.  And excellent blog!

  • Anonymous

    2/12/2010 4:44:22 AM |

    I take Natures Calm at night (makes me sleep like a baby) and pop a few mg citrates during the day.  If I take Natures Calm during the day I get way too relaxed.

    Heart palpitations and leg cramps seems to go hand in hand with me. Extra mg knocks out both.

    However, one time I ran out of my citrate tabs and grabbed a container of a mag/cal supplement.   That combination did nothing for me, no matter how much I took.  The ratio of calcium to mg was way off favoring calcium.  Also, I notice if I take in too much yogurt and cheese the effects of my mg seems to wane.

    My only theory is that its true that if your calcium intake exceeds your mg intake by too much it can block the benefits. So far that has been my experience. Not a psychosomatic response, since I knew nothing of it until I looked it up after the cal/mg  blend didn't help me. Wow.

  • Barkeater

    2/12/2010 7:09:40 PM |

    I looked into blood tests, but concluded that that was not a very practical or accurate way to assess magnesium deficiency.  

    I concur with those that say if you have symptoms that might be magnesium deficiency, go ahead and supplement because your probably are deficient and there is no harm in it.  I had a lifetime pattern of getting severe leg cramps any time I exercised hard (like playing soccer) for more than say 80 minutes.  That was a very good hint.

    But, I was not content to leave it at that.  I looked at my diet, the reported mg content of food in it, and the RDA for me of 420mg of magnesium per day.  It was totally obvious that, even with my pretty healthy diet, I must be below 300mg of mg per day.  IT IS SO EASY TO GUESTIMATE YOUR NUTRIENT INTAKE THIS WAY, but nobody seems to suggest it.  Instead you see mindless blather about eating a few other foods that are high in mg -- go ahead and do the math and you will see that you need to be really dedicated to make that work.

    This kind of a self-assessment of the nutrient content of your normal diet, in many cases, will show that you don't take in recommended levels of iodine, potassium, and selenium, either.  Like mg, these are involved in countless ways in our biology.  Potassium is the one of these that is trickier to supplement - that you probably need to correct by shifting salt use to mixed salts (or no-salt) that have potassium chloride.  It turns out that my cramping issue needs both mg and potassium to be kept at bay, but together they work.  (Getting salt-potassium in better balance is good for blood pressure, too.  My systolic and diastolic dropped 10 points each since joining TYP a year ago.)

    I supplement mg with mag water, per the TYP web site.  Cheap and absorbable, no side effects, easy to incorporate into your regimen, and nice not to take one more pill.

  • Dr. William Davis

    2/12/2010 7:41:41 PM |

    The only way to truly know your magnesium status, short of waiting for clear-cut evidence of deficiency (muscle cramps, heart rhythm disorders, etc) is to check a blood level, preferably an RBC level, not a serum level. The RBC level is a rough approximation of tissue levels.

  • DrStrange

    2/14/2010 6:49:56 PM |

    If you hunt around you can also get magnesium ascorbate which gives a nice two-fer.  I get mine from Intensive Nutrition, one tablet contains 100mg magnesium and 1000 mg vit C as ascorbate.  Also, NOW brand makes a powdered one and Source Naturals also...

  • Anonymous

    2/16/2010 7:23:15 AM |

    Magnesium is one of the essential components necessary for the body to function normally. It is not just necessary for human; rather, it is essential for all living organisms as magnesium ions are a part of the nucleic acid chemistry of all living cells and things. Because it is so vital, you can imagine what should happen if someone were to be magnesium deficient. It is not a pretty picture, indeed.

    More Info: Sign and Symptoms of Magnesium

  • chris

    2/16/2010 4:56:50 PM |

    Theres no need to supplement if you are eating several servings of legumes and nuts every day.

    I have replaced most grain use in recipes with legumes, and nuts are a good food on the go.

  • Mike

    2/16/2010 11:55:59 PM |

    "Several serving s of legumes and nuts" will effectively increase your intake of inflammatory lectins and omega-6s.

    I'll stick to supplementing.

  • Anonymous

    2/24/2010 11:47:52 PM |

    My leg cramps were also resolved by magnesium supplementation. Many people don't realize that eating grains will severely inhibit the absorption of minerals, due to their phytate content (an "anti-nutrient") and will therefore contribute to magnesium and other mineral deficiencies. The phytates in grains can be mostly eliminated by soaking and/or sprouting them before consumption.

  • L. Cramp

    3/16/2010 7:52:39 PM |

    I have always been fascinated by the question ,why some people can and others cant. I spent years trying to figure this out. At first it was mainly for myself. I remember growing up with little confidence and under the impression that others were more capable than I was. The fact was that this impression was true. It was true because i believed it.

  • Helena

    4/15/2010 6:54:29 PM |

    Hi Dr Davis,

    I just had my first experience, at least I think so, of arrhythmia on Tuesday night... My heart was beating really, really fast for about a minute or two and then it all just stopped and went back to normal.

    I try to take 150 mg of magnesium every day (on Tuesday I forgot to take all my supplements). What is your recommendation on how much I should take each day? Does it matter what kind, should I spread it out over the day or is once a day dose ok?

    The whole experience was a bit overwhelming for me and I want to make sure it does not happen again! If it however does, should I go to a doctor? What can I requests as far as 'safe' tests?

    My experiences with tests are usually pretty bad as I always end up in the 'normal' range... whatever that means. And I get the "You are just a crazy hypochondriac, go home" look from the doctors.

    Appreciate your comment on this. Thank you.

  • TedHutchinson

    4/16/2010 9:25:42 AM |

    @ Helena
    150mg magnesium daily probably isn't sufficient.
    Krispin's formula suggests someone 70 kilos = 150 pounds should have a  total intake between 350mg to 700mg daily.
    The current magnesium RDA of 420mg/men, 320mg/(non-pregnant) women but average US female intake is just 228mg/daily.

    You also do not state the form of magnesium supplement you take.
    Many of the magnesium blends available include magnesium oxide. It's likely, where percentages are not stated, this cheapest (least effective) form constitutes the bulk present. Only 4% of magnesium oxide is absorbed.

    Magnesium is best absorbed (like calcium) from small amounts, through the day, with meals. I find it easier to take magnesium with each meal of the day and before bed.

    Does a higher ratio of serum calcium to magnesium increase the risk for postmenopausal breast cancer?
    This paper hypothesizes that low levels of magnesium  increase calcium retention, higher calcium levels further depress magnesium absorption and the resulting cellular imbalance leads to cancer initiation. Magnesium intake is an extremely important aspect of Vitamin D supplementation that is often overlooked.

  • Dave, RN

    5/14/2010 4:25:51 AM |

    TEedHutchison, I've been there with the diabetes forum. When I suggested a  paleo very low carb diet to a confused person who was just diagnosed, I was called a "dangerous extremest" by who I believe was the moderator. All of my suggestions about magnesium and D3 were poo-pood by him, and besides an extremest, I was brushed of as "one of those people who occasionally shows up here".

  • Helena

    5/27/2010 3:05:03 PM |

    Thank you Ted.
    I will look at what type of Mg I am taking... and also increase the dose. If not I will order the magnesium you suggested. I have not had an event since that one time but I have had some slight feelings of dizziness and fluctuations in pulse. This is all due to coming off of a birth control pill that was killing me I am sure, it just takes time getting to know your body once again after years on synthetic hormones. Thank you again.

  • Anonymous

    5/28/2010 3:54:24 PM |

    Just want to say what a great blog you got here!
    I've been around for quite a lot of time, but finally decided to show my appreciation of your work!

    Thumbs up, and keep it going!


  • Anonymous

    6/7/2010 2:49:32 AM |

    Dr. Davis, I stumbled across The Heart Scan Blog after months and months of being frustrated with a heart arrhythmia that appeared out of the blue after a period of high stress and anxiety attacks late last fall.  I was feeling a lot of "skipped heartbeats" and immediately went to a cardiologist who ordered a stress echo and 24 hr holter monitor.  He told me it was a benign premature heartbeat which I was relieved about but after months of getting 20-30 a day, it was all I could think about.  Reading your blog and the discussion regarding magnesium has given me hope.  A few weeks ago, due to ease, I  was eating large quantities of quinoa which is rich in magnesium and noticed that the skipped beats subsided a bit to 5x a day.  I didnt know if there was a link but I am hopeful that there is a link and willing to give magnesium a try.  I've already purchased the magnesium taurate - what do you recommend in dosage? Please note, I am always worried about taking any supplements....are there negative side effects. Could it make my heart arrhythmia worse?  Thanks so much!! I am desperate to get back to a life where the skipped beats are not on my mind 24/7.

  • Phyllis

    6/9/2010 5:37:37 PM |

    I have had an annoying arrythmia for a very long time. Its worse at times, better at times. I have seen a cardiologist. He did an ekg which said that I had had a heart attack. Echo was done and Doc said I had not had a heart attack, but have PAC's and a leaky tri-cuspid valve. He also did a 24 hour holter monitor. Basically he said there wasn't anything bad wrong, but he put me on sotalol to try and clear up the palpitations and rapid-ish heart rate. Also, my BP was in the 100's range for the lower number.
    I have not noticed much difference as far as the palpitations go, after over a year on the sotalol.
    I have however gotten my eating/health under control, with low carb, I have lost around 45 pounds and am within 10 pounds of my goal weight. My blood pressure is running around 117/75 most mornings, I feel like a new person, now if these annoying palpitations would just go away...
    To that end, after reading this post I have just recieved my bottle of magnesium taurate and plan on adding it to me list of supplements which includes 5000 units of vitamin D per day for about the last 6 months.
    My reason for posting this here is I hope to be posting soon that the palpitations have cleared up.
    LOVE this blog, its one of the very few that I have discovered and gone back and read many of the older posts.
    God Bless you, Doc, for taking the time to really help people!

  • Tiza

    8/30/2010 6:37:32 PM |

    Nice blog. Basically, I couldn't do without my magnesium malate. If it wasn't for the magnesium, I probably would not be able to walk, or at least not very good because of my back.

    I noticed that someone asked about having their magnesium tested. First, blood tests are really worthless for testing magnesium. I've never had mine tested, but there is a test that Dr. Dean talks about.  It's here at this link, and it's a non-evasive test:

  • blogblog

    10/31/2010 8:42:09 AM |

    The cheapest and simplest magnesium supplement is Epsom Salts (magnesium sulphate). It only costs about $1/year. It is also extremely safe and is widely used in medicine. About 1/10th of a teaspoon dissolved in 1L water will do the trick. It is also an extraordinarily effective laxative in higher doses.

  • buy jeans

    11/2/2010 8:41:18 PM |

    Magnesium supplementation is therefore necessary for just about everybody to maintain normal tissue levels. (The exception is people with kidney disorders, who should not take magnesium without supervision, since they retain magnesium.)

  • Drew

    1/6/2011 7:04:43 PM |

    Magnesium truly is the body's "master mineral." Without it, so many other minerals cannot be properly used in the body.

    Most people have a hard time with taking oral magnesium supplements and don't get the results their body needs.

    I was fortunate enough to come across "Transdermal Magnesium" or better know to me now as "Magnesium Oil."

    Magnesium Oil is simply a magnesium rich mineral solution that has been sourced from some body of salt water.

    Since the minerals in sea water are constantly being subjected to sunlight, it in turn makes the minerals ionic (ready for the body to use).

    It is as simple as spraying the solution on your skin and the body absorbs it directly into the cell. No digesting needed!!

    There are some concerns to be aware of however. Where are they sourcing their raw materials from? Is it clean of pollution and heavy metals?

    I have researched about every brand out there and a lot of them can be misleading.

    My favorite, by far, is Magnesoothe! They can be found at They handle there product in the very best manor from start to finish. They have the most helpful customer service. And their source goes unsurpassed!

    Their source is the Dead Sea and there is no other body of salt water like it on the  face of the planet! You can read more on the Dead Sea here at

    If you want to know more on the purity of Magnesoothe, you can read that here at

    I hope that my 2 cent will be helpful to someone.

    Best of Health!
    The Magnesium Man

  • Hal

    4/26/2011 8:51:32 PM |

    About 1 1/2 years ago I started having arrhythmia issues which were diagnosed as atrial fibrillation.  I had my atenolol increased and this did help some but I was still having (mostly short) episodes on an almost daily basis a month later.  Looking around the net I found a paper that talked about how using preoperative Mg for open heart surgery reduced the incidence of AFib after surgery.  So I decided to try Mg.

    I started taking it to tolerance (IE. increased dose until I had loose stools and then back off a little) and in about a week the AFib episodes had gone away.  Now I only have AFib episodes if I forget taking Mg for a few weeks and it goes away in a few days if I start taking Mg again.

    What I find most distressing about this is that none of my doctors even considered recommending giving Mg a try as far as I can tell.   Why wouldn't it be one of the first things they try if there is no other apparent cause (like high/low potassium, for example).  In those cases where I told the doctor that Mg had helped their reaction was mostly along the lines of Mg can't cause too many issues so go ahead and take it.  But nothing about how it should be considered for treating arrhythmia.

  • kend

    11/21/2011 2:57:24 AM |

    A few yrs. back, I read a very interesting article written by a cardiologist concerning his having successfully treated a patient with arrythmia  with an intravenous solution of magnesium.

  • Ray

    2/9/2012 8:30:57 PM |

    I have had arrythmia for a few years now, I have been to two different consultants and both say "it''s benign and won''t do any harm" I however could not stand the horrible fluttery feeling when it happened so they put me on 2.5mg  of bisopronol. I found this was making me dizzy and so after getting the all clear from my angiogram with the doctors ok stopped taking them. I had read about the successful results of taking mangnesium and so at the start of this new year started taking 1000 mg a day and started a diary of taking my blood pressure and heart rate three times a day (I have a good home blood pressure meter that shows up arrythmia as well)  So far it seems to have cleared the arrythmia apart from the odd reading.
    I forgot to mention that where I differ from everyone elses posts is that I have a very slow pulse, 40-45 sitting and only 65 when I fast walk to work but it will go up to 120 if I do a hard session on the treadmill.  I am 61 and did have a slow heart rate when I did long distance jogging up to the age of forty.
    I would be interested to hear from anyone else that has a slow pulse.