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Information on the latest vitamin D news and research.

Find out more information on deficiency, supplementation, sun exposure, and how vitamin D relates to your health.

Are we paying enough attention to magnesium?

If you don’t take a magnesium supplement, chances are you are magnesium deficient, unless you eat 6 or more servings of vegetables every day along with seeds and nuts. According to the Food and Nutrition Board, the RDA for magnesium varies with age but is approximately 400 mg for adult men and 320 mg for adult women, but almost no one gets that much from modern day diets.

Magnesium deficiency has been associated with cardiovascular disease, hyper tension, diabetes and osteoporosis.

Institute of Medicine (US) Standing Committee on the Scientific Evaluation of Dietary Reference Intakes. Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. Washington (DC): National Academies Press (US); 1997.

Repeated studies show the average American has inadequate intakes of magnesium.

Magnesium consumption is particularly low among adolescent females, adult females, and elderly men, with one study showing that 85%, 80%, and 75%, respectively, of the population groups having mean magnesium intakes below their respective RDA.

Morgan KJ, Stampley GL, Zabik ME, Fischer DR. Magnesium and calcium dietary intakes of the U.S. population. J Am Coll Nutr. 1985;4(2):195-206.

In one NHANES study, none of the African Americans studied met the RDA for magnesium.

Fulgoni V 3rd, Nicholls J, Reed A, Buckley R, Kafer K, Huth P, DiRienzo D, Miller GD.  Dairy consumption and related nutrient intake in African-American adults and children in the United States: continuing survey of food intakes by individuals 1994-1996, 1998, and the National Health And Nutrition Examination Survey 1999-2000. J Am Diet Assoc. 2007 Feb;107(2):256-64.

In another study, the actual intakes of magnesium were 202 mg/day for children from 1 to 5 years old, 228 mg/day for women and 331 mg/day for men, well below the RDA for all the groups.

Lichton IJ.  Dietary intake levels and requirements of Mg and Ca for different segments of the U.S. population. Magnesium. 1989;8(3-4):117-23. Review.

For older Americans, a study showed that both men and women had median diet intakes below the RDA for magnesium. That is, less than half had adequate intakes.

Hallfrisch J, Muller DC.  Does diet provide adequate amounts of calcium, iron, magnesium, and zinc in a well-educated adult population? Exp Gerontol. 1993 Jul-Oct;28(4-5):473-83.

According to the last Food and Nutrition Board’s review of magnesium, “Magnesium is a required cofactor for over 300 enzyme systems. It is required for both anaerobic and aerobic energy generation and for glycolysis, either indirectly as a part of the Mg-ATP complex or directly as an enzyme activator. Magnesium has also been shown to be required for mitochondria to carry out oxidative phosphorylation. The mitochondrial enzymes utilize the magnesium chelate of ATP and ADP as the actual substrates for phosphate transfer reactions.”

In other words, adequate magnesium is crucial.

As there is no magnesium guru in the world, no one person who is the magnesium expert, magnesium is what Professor Robert Heaney calls an “orphaned mineral.” No one is studying magnesium exclusively and thus there is no world expert on magnesium. Magnesium is involved in the metabolism of vitamin D and has complicated interactions with vitamin D and calcium.

Fatemi S, Ryzen E, Flores J, Endres DB, Rude RK. Effect of experimental human magnesium depletion on parathyroid hormone secretion and 1,25-dihydroxyvitamin D metabolism. J Clin Endocrinol Metab. 1991 Nov;73(5):1067-72.

Doctors mistakenly think that a blood magnesium level will assess magnesium stores in the body. However, serum magnesium is homostatically controlled, so assessing serum magnesium to assess total body magnesium stores makes about as much sense as measuring a serum calcium level to assess total body calcium stores. Measuring either tells you nothing unless total body stores are extremely low.

In my opinion, everyone should take a magnesium supplement with their vitamin D, at least 300 mg/day for men and 200 mg/day for women. While you may be one of the few with adequate dietary intake of magnesium (such as those who eat a lot of vegetables and seeds and nuts), it is more likely you are magnesium deficient. I believe magnesium supports vitamin D by acting as a cofactor in the enzymes that metabolize vitamin D.

If you are a graduate student interested in vitamin D, consider specializing in magnesium. You could eventually become the world’s magnesium guru like Professor Robert Heaney is the world’s calcium guru.

  About: John Cannell, MD

Dr. John Cannell is founder of the Vitamin D Council. He has written many peer-reviewed papers on vitamin D and speaks frequently across the United States on the subject. Dr. Cannell holds an M.D. and has served the medical field as a general practitioner, emergency physician, and psychiatrist.

13 Responses to Are we paying enough attention to magnesium?

  1. Rita and Misty says:

    Salutations and greetings!

    Dr. Cannell, what a wonderful piece on the necessity of magnesium–thank you!

    You have written it at an appropriate time, as several VDC members have contacted me regarding changes to the co-factors section on the new website. It appears that the language regarding magnesium has changed a bit.

    But, here you’ve addressed our need for magnesium so nicely.

    I have heard of vitamin d deficient individuals experiencing aches and pains similar to a low grade flu upon supplementing with high amounts of d3. I’ve often wondered if these symptoms were directly related to magnesium deficiency.

    Magnesium is certainly crucial–especially since the standard American diet does not include tons of veggies, seeds and nuts.

    However, I would like to stress that (from my personal experience) adequate magnesium intake doesn’t replace the need to supplement with d3.

    I am one of those few (weird?) people, whose diet has always included tons of veggies, seeds and nuts…PLUS, I have (since forever) taken 600 mg magnesium daily (also adequate boron and zinc–and, 6,000 iu d3 daily).

    Yet, (and I am so sorry for being repetitive) when my 25(OH)D level was tested 8 years ago, it was only 32 ng/ml.

    Thank goodness for this website.

    (if I were younger, I would pursue the vitamin d/mag connection, for sure)

  2. Edd says:

    Hi All–
    Vitamin D, Magnesium, and…(don’t forget) Vitamin K2 (see the vitamin K2 research by Cees Vermeer and Leon Schurgers, for example, on PubMed). I think of these three as always going together.

  3. Rita and Misty says:


    You are absolutely correct about K2. I didn’t add this supplement to my protocol until 2 years ago, after reading about the benefits here on Dr. Cannell’s website. But now I wouldn’t be without it.

    K2 controls where calcium ends up in our bodies. It ensures that the calcium goes into our bones and blood, rather than our arteries or muscles, or other organs. If you are deficient in K2 (which many of us are), you may end up with hardening of the arteries and age-related brain diseases like Alzheimer`s disease, or certain cancers (like liver cancer in women and prostate cancer) and bone loss. K2 has also shown to protect nerve cells from oxidative stress.

    I do take a mixed K supplement daily, and recommend this to my friends as well.

    I would say that my favorite go to supplements are:

    1. D3
    2. Magnesium
    3. Mixed K supplement
    4. Boron (I love my Boron–very underrated imo)
    5. Zinc
    6. Iodine
    7. Selenium (important if you do take Iodine)

  4. Rebecca Oshiro says:

    I have seen dramatic results in myself and others taking 1-2 tsp per day of the magnesium citrate supplement Calm (best prize on amazon.com).

  5. Ian says:

    Rebecca, what are the dramatic results you speak of after taking the MgCitrate?

    I too take magnesium citrate 300mg twice daily. I did this to alleviate severe muscle cramps, twitching and essential tremor as a result of cervical and lumbar spine stenosis. (possibly causing what they call fibromyalgia, although I am very dubious of that diagnosis) The lumbar stenosis also causing calf swelling. After advice from Prof. Julia Newton of Newcastle University UK. I started on magnesium (nothing else I was prescribed worked). The magnesium stopped about 90% of the cramps in a short time. The twitches and the tremor stopped completely. Interestingly my right calf normalized but the left calf is still fairly enlarged. This also makes me think the calf swelling is due to the lumbar stenosis which is slightly worse on the left.

  6. WisdomWellness says:

    I don’t believe anyone has commented that there IS a blood test that looks at body sufficiency of magnesium. Order a red blood cell (RBC) magnesium test. 98% of our patients come back low. The reference range from Quest is 4.0-6.4 mg/dL. We like our patients up over 6.0. When oral magnesium bowel tolerance is an issue, or when patients are very low, we recommend using a topical magnesium product. Love the one from Xymogen, but a quick internet search will show you several other options.

    Cheryl Wisdom MS RN FAARFM

  7. Logene says:

    Carolyn Dean, M.D., N.D. has researched magnesium, and has written, THE MAGNESIUM MIRACLE.

  8. Holly says:

    Another possibility is to make a “magnesium oil” and spritz on your skin multiple times a day. It’s readily absorbed (can sting initially), some say it’s better than an oral magnesium supplement. Recipe is simple and inexpensive relative to purchased prepared magnesium oil. Here’s one recipe of many out on the web: http://www.foodrenegade.com/how-make-magnesium-oil/?utm_source=feedly

  9. logan_n@q.com says:

    In Medline one can find a fair number of hits on bioavailability, such as —
    Magnes Res. 2005 Dec;18(4):215-23.
    Bioavailability is a point to include in articles about magnesium, since the common Mg oxide is not very available. In the Magnesium Research article of 2005, Coudray et. al. found that the gluconate was best in rats. One can get the gluconate from PureBulk.

  10. Rita and Misty says:


    Thank you for this information regarding vitamin d/magnesium. I’ve suspected as much. Individuals have reported to me that upon commencing high dose vitamin D supplementation they feel like the have a low grade flu…I’ve thought that this might have to do with a corresponding magnesium deficiency…and it appears from your words that this is true.

    Be well,

    (and thanks for posting your name!) :)

  11. Mark Haymond says:

    Rita and Misty,
    You should add Vitamin C to your favorite supplements. Most people think they know about Vitamin C (ascorbic acid), however, I believe that most people don’t know what they need to know.

    Humans are among five living things that do not make ascorbic acid internally (i.e. primates – i.e. monkeys, gorillas etc; guinea pigs; a fruit eating bat in India; one kind of fish; and humans). All other animals on earth make ascorbic acid internally from glucose and they make large amounts of it every day. A 150 pound goat, for example, makes about 15 grams (15,000 mg) every day. If the goat is under stress it can make up to 100 grams (100,000 mg) in a day. Compare that amount to the RDA of 60 mg for humans.

    So, are humans different than all other living things on earth so that we don’t need ascorbic acid and every other living thing on earth needs it, in massive amounts? The answer is, no. We are not different. Humans need ascorbic acid every day also, yet we don’t make it internally like all other animals. If we are deprived of all ascorbic acid in our diet we will die of a deficiency condition called scurvy within about four months.

    Dr Cannell likes to explain that Vitamin D is a seco steroid hormone. We need it in much larger amounts than a simple vitamin. Similarly, ascorbic acid is a stress hormone. We need it in much larger amounts than the RDA. Any kind of stress (mental, emotional, or physica) uses up ascorbic acid. This is why a person under a lot of stress will get sick. Their ascorbic acid stores are minimal to begin with. With added stress their ascorbic acid is all used up. They are then sitting ducks for any pathogen that they pick up easily in their daily contacts. Without ascorbic acid many components of our immune system, such as white blood cells, are simply not made or are not sufficient to handle the pathogen. Without white blood cells constantly coming to our rescue we get sick.

    Immune function is only one body process that requires ascorbic acid. There are 4,000 body processes that require ascorbic acid. Collagen maintenance is another one of those processes, a very important process. The making of collagen requires ascorbic acid. Collagen makes up about 33% of all of the protein in our body. Collagen is the glue that holds together all of our tissues, bones, muscles, skin, organs etc. Without collagen we would fall apart. Since we are living organisms we are constantly wearing out and sloughing off old tissues and making new tissues to replace the old. Without at least some ascorbic acid everything in our body will begin to break down because there is no collagen maintenance. This is what happens in scurvy. Bones, muscles, joints and organs begin to break down, stop functioning completely, and become painful. Gums start to bleed. Teeth become loose or fall out. Blood vessels, capillaries, veins, arteries breakdown because there is no collagen maintenance to maintain them. Without collagen maintenance the blood vessels will start to leak blood. Bruises will develop easily. Eventually the person will bleed to death internally. This is what happens in scurvy. The person will simply die because they don’t have the ascorbic acid necessary to maintain the processes of life. If you read about sailors who developed scurvy for lack of ascorbic acid you will find that in addition to all the signs mentioned above, they could die suddenly, mid sentence, while talking to a fellow sailor.

    A small amount of ascorbic acid will prevent the overt signs of scurvy. The RDA of 60 mg was established to prevent the overt signs of scurvy. But, the overt signs of scurvy is the last sign of a deficiency of ascorbic acid, not the first sign. Many of the 4,000 body processes stop functioning before the overt signs of scurvy appear. Our goal is not to maintain our health just above the level of death from scurvy. Our goal is to maintain our health in a robust manner.

    The researchers of ascorbic acid explain that most people, by taking 60 to 100 mgs per day, keep their ascorbic acid levels just above the level of the overt signs of scurvy. They call this condition “chronic subclinical scurvy.” They look healthy, but the processes of life that require ascorbic acid are not maintained adequately, just like with Vitamin D, and therefore many body processes and body tissues begin to breakdown or stop functioning properly (we have many different names for the breakdown of body processes that may stem from a deficiency of ascorbic acid). Some people even exhibit the signs of scurvy but they don’t recognize them as such, such as bleeding gums, nose bleeds, loose teeth, easy bruising, tissues failing to heal. We have modern names for all these things. Try an old name: scurvy or a deficiency of Vitamin C.

    Nobel prize winning chemist Dr Linus Pauling explained that cardiovascular disease is a sign of chronic subclinical scurvy where the arteries around the heart are not maintained properly. Without adequate collagen maintenance the arteries begin to breakdown. The body senses that there is not enough ascorbic acid and the body sends a healing response to patch the arteries, a substance called Lipoprotein A (a form of cholesterol). The sticky LpA sticks to the damaged arteries around the heart and builds up until it causes a heart attack. The body’s healing response causes the heart attack. If the blood vessels and veins throughout the body are maintenained by providing adequate ascorbic acid for collagen maintenance to carry on properly, there is no heart disease. Have you ever heard of an animal having a heart attack or stroke? Why don’t animals have heart attacks? Because they make ascorbic acid internally and their arteries don’t break down and need to be patched (the five animals mentioned above that don’t make ascorbic acid internally can die of a heart attack). Dr Pauling also explained that adequate amounts of ascorbic acid and the two amino acids L-lysine and L-proline can reverse cardiovascular disease by healing the arteries.

    If you would like to read a simple explanation of the Linus Pauling therapy for heart disease, read the article at the following link:

    A Simple Natural Therapy for Cardiovascular Disease

    Or you can go here for a lot more information about the Pauling Therapy for heart disease:

    So, how much ascorbic acid do you need each day to prevent chronic subclinical scurvy? A lot more than 60 mgs. Dr Frederick Klenner, Irwin Stone and others say that the keys to proper amounts of ascorbic acid is dose, frequency and duration. Most studies dealing with ascorbic acid use a much too small dose, way too infrequently, for a much too short duration. Then when the study comes to the conclusion that ascorbic acid has “no appreciable impact,” they are correct. At that dose, frequency, and duration it will have no appreciable impact. But, if we provide a large enough dose, frequently enough, for a long enough period of time it can have a huge impact. Dr Robert Cathcart called it The Ascorbate Effect. What much research considers a mega dose, Drs Klenner, Stone and others consider a small dose. I take at least 10 grams (10,000 mgs) every day, throughout the day, more when I am under stress or are sick or injured (remember how much animals make internally). I recommend two grams at breakfast, lunch, dinner, and bedtime (eight grams each day). Don’t take multiple grams all at once in the morning. It will cause a quick case of loose bowels. Your body needs what it needs when it needs it (depending on your stress level). If you take more than your body needs at that moment your body will tell you with a quick case of loose bowels. You are not sick. You just need to go once. If you would like to read more about titrating to bowel tollerance read the following article:

    Vitamin C: How to Use The Great Missing Vitamin Supplement to The Art of Getting Well

    Dr Robert Cathcart MD developed the concept of titrating to bowel tollerance. If you would like to read his article where he explains this, read here:


    If you want to read more about ascorbic acid just google any of the following and read their own writings:

    Irwin Stone
    Thomas Levy
    Steve Hickey – Manchester England
    Hillary Roberts – Manchester England
    Robert Cathcart
    Linus Pauling
    Frederick Klenner

    If you want to read about Dr Archie Kalokerinos’s discovery of the cause and prevention for Sudden Infant Death Syndrome (SIDS) read this and share it with everyone you know:

    Eradicate Sudden Infant Death Syndrome (SIDS) Now

    Or get a copy of Dr Kalikerinos’ book, “Every Second Child” (if you can get a copy).

    Get a copy of the book, Vitamin C, The Real Story, or read this review of the book:

    If you really want to learn more about ascorbic acid (Vitamin C) go to the Vitamin C Foundation web site:


    You can also find a lot about Vitamin C on the doctoryourself.com web site. You’ll have to scroll down and find what you want about Vitamin C:

    Vitamin C needs to be added to your list of favorite supplements.

  12. Rita and Misty says:

    @Mark Haymond~~

    You are talking to a gal reared on Robert Rodale, Adele Davis, and LINUS PAULING.

    I am the Queen of healthy living and good exercise…plus good sleep habits, to boot!

    Regarding Vitamin C, it has been on my favorite supplement list for almost 49 years. My mom was addicted to Linus Pauling’s research. And, I knew his name probably before I knew some of my own relatives’ names. I think my mom still has a shrine to Linus Pauling in her home.

    I take 2 grams of Vitamin C daily. I used to take more. I never have taken less.

    But, Vitamin D3 is supplement NUMERO UNO in my book, because our indoor lifestyles make it impossible to get D the way nature intended, by SUNSHINE; and as we all know, there are absolutely no food sources which will provide us with 5,000 iu d3 daily.

    Be well,