Magnesium and you-Part I

If this were 10,000 B.C., you'd get your drinking water from streams, rivers, and lakes, all rich in mineral content. Humans became reliant on obtaining a considerable proportion of daily mineral needs from natural water sources.

21st century: We obtain drinking water from a spigot or plastic bottle. Pesticides and other chemicals seep into the water supply. Municipal water purification facilities have intensified water purification in most communities to remove contaminants like lead, pesticide residues, and nitrates. (For a really neat listing of the water quality of various cities, the University of Cincinnati makes this data available.)

But intensive water treatment also removes minerals like calcium and magnesium.

Many people have added water filters or purifiers to their homes,, like reverse osmosis and distillation, that are efficient at extracting any remaining minerals, converting “hard” into “soft” water. In fact, manufacturers of such devices boast of their power to yield pure water free of any “contaminant,” minerals like magnesium included. The magnesium content of water after passing through most commercial filters is zero.

Modern enthusiasm for bottled water has compounded the problem. Americans consumed a lot of bottled water, nearly 8 billion gallons last year. In the U.S., nearly all bottled water has little or no magnesium.

The result is that we can no longer rely on drinking water to provide magnesium. The Recommended Daily Allowance (RDA)—the amount required to prevent severe deficiency—for magnesium is 420 mg per day for men, 320 mg/day for women. In cities with the highest magnesium water content, only 30% of the RDA can be obtained by drinking two liters of tap water per day. In most cities, only a meager 10–20% of the daily requirement can be obtained. That leaves between 70–90% that needs to come from other sources. As a result, the average American ingests substantially less than the RDA.

Comments (11) -

  • Anonymous

    5/15/2009 4:24:00 PM |

    I would just love to drink my tap water for necessary minerals but my city has deemed it necessary to forcefully medicate it's inhabitants by adding fluoride to it so I go to my local water store and get my drinking water.

    I have hashi's so I must avoid flouride (except for having to bathe in the citywater)as much as possible.  Sometimes I get distilled and sometimes I get the reverse osmosis for my drinking water.  I add Himalayan 'sea' salt to the water to add back in the minerals but I really have no clue if that is adequatly providing the minerals my body needs so I also take vit/min supplement and additional magnesium(sometimes before going to bed - it seems to allow a more restful sleep and makes me calmer overall).

    Some of the proponents of distilled water drinking say that absorption of minerals from water is negligible.  I don't know if there are any studies out there to prove if this is so.  My guess is that it would depend on the gut health of the individual.

    I also give my pets the bottled water with the sea salt added to it.  they don't need no steenkin fluoridated tap water either.

    Growing up we had well water and it was delicious.  I don't know if anyone ever tested the water for it's mineral content, though.  


  • Ares Vista

    5/15/2009 9:41:00 PM |

    Most people would do well to take a vitamin/mineral supplement each day. It's simple to do, and relatively inexpensive. Relying on our diets to provide us with the right nutrients can leave out important ones.

  • mongander

    5/16/2009 12:53:00 AM |

    Fortunately, I live in Hot Springs, Arkansas where I have free access to 140° thermal spring water, with 4.9 ppm Mg.  Don't know if that's sufficient but that's all I drink.

  • Jeremy Fox

    5/16/2009 1:02:00 AM |

    There are many types of magnesium available in vitamin stores. Which is the best type to buy? I am curious about absorption by the body and not including a lot of potentially unhealthy ingredients?.

  • Dennis Mangan

    5/16/2009 2:53:00 PM |

    Magnesium oxide has been shown to be poorly absorbed, while magnesium aspartate releases aspartate, which *might* cause some excitotoxicity. Your best bet is probably magnesium citrate or malate.

  • Steve

    5/16/2009 4:38:00 PM |

    Jeremy Fox,

    Read the first comment from this post by Dr. Eades for what kind to buy:

  • Kismet

    5/16/2009 5:25:00 PM |

    Actually, no one should take a multi vitamin (= the shotgun approach) without talking to a knowledgable doctor and/or doing a lot of research.

    And NO ONE should take a cheap generic multi. That's suicidal and I'm serious.
    The evidence conclusively proves that generic multis (badly formulated, over-/underdosed, etc) are a waste of money at best and dangerous at worst. (1, 2)

    There are two *vastly* superior approaches:
    A. fix your diet (check nutrient intake using CRON-o-meter) and supplement whatever you are lacking (i.e. single nutrients).
    B. take a well-formulated *low dose* multi á la AOR orthocore (although, it's too high in folic acid in my opinion)

    (1) Cochrane Database Syst Rev. 2008 Apr 16;(2):CD007176.
    Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases. Bjelakovic G, Nikolova D, Gluud LL, Simonetti RG, Gluud C.
    (2) Multivitamin use and risk of cancer and cardiovascular disease in the Women's Health Initiative cohorts.
    Neuhouser ML, Wassertheil-Smoller S, Thomson C, Aragaki A, Anderson GL, Manson JE, Patterson RE, Rohan TE, van Horn L, Shikany JM, Thomas A, LaCroix A, Prentice RL.

  • Nameless

    5/17/2009 1:25:00 AM |

    I'm curious what Dr. Davis recommends regarding magnesium intake and what specific form.

    Magnesium glycinate (Albion), orotate or a taurate may be preferred. The Albion's have good absorption studies. And for orotate there is little bit of evidence is can reduce cholesterol (maybe), and some decent studies on improving heart health.

  • Anna

    5/18/2009 3:24:00 PM |

    I enjoyed two books on magnesium, The Magnesium Factor and The Magnesium Miracle.  They complement each other well, as the first one is more about magnesium's role and the second has more practical info about supplementing.

    We used to take magnesium oxide, but it is the magnesium salt with the lowest absorbability (only 4% I think), so the dose must be higher.  Consequently it also has more of a laxative effect than some other magnesium preparations.  We're taking a magnesium complex (oxide, aspartate, citrate, and taurate) or magnesium taurate now, though I do keep the magensium oxide around for the times when a mild laxative is useful (esp with travel).

    The Magnesium Miracle frequently mentions magnesium oil (magnesium chloride?) which isn't really an oil, but feels like one when applied topically.  I haven't found it in local stores (no one has heard of it), but it is available online.  Has anyone used magnesium oil?

  • billye

    11/17/2009 4:10:15 AM |

    I have bought on line and used used Swanson's magnesium oil topically-5 short sprays on each arm prior to bedtime on a daily basis.  I have used about 40% of 8fluid ounces and I just got my blood test results.  normal range 1.5 to 2.5.  My result was slightly high at 2.7.  By applying it topically, you get full absorption.  Dr. T from " put me on this system.