How to get your calcium and magnesium balance right

© Kristina. Avocado: 29 mg magnesium per 100 g
© Kristina. Avocado: 29 mg magnesium per 100 g. Avocados are also a super source of vitamin E and folate.

Your calcium to magnesium ratio is a very big deal indeed, and over the long term, will affect your health in dramatic ways — for your heart, your bones, your energy, and your mind.

Nearly everyone is magnesium deficient

Magnesium is critical, and yet nearly everyone is deficient. It’s hard to get optimal amounts in your diet unless you carefully plan it. And our food has less than it should because of intensive farming and the use of herbicides like glyphosate that bind to magnesium and other minerals in soil. 

We need magnesium for over 700 enzymes, we need it to make energy, DNA, RNA and proteins. and it’s a structural part of healthy bone. Muscle energy in your body is solely in the form of Mg2-ATP — magnesium-adenosine triphosphate.

I believe in getting nutrients from food, because nutrients come with their natural cofactors, other elements that help the body use them, but magnesium is one nutrient that may be wise to supplement.

A hundred years ago, our diet might have had around 500 mg of magnesium a day. These days, it could be as low as 200 mg. And magnesium is so easily lost in sweat if you train hard, it’s lost if you’re stressed, take drugs, drink alcohol or caffeine, smoke and so on. Hard to get and easily lost.

Deficiency of magnesium can cause a whole array of symptoms… anxiety and panic attacks, irritability, agoraphobia, depression, fatigue, sensitivity to bright light and loud noise, cramps, restless legs syndrome, constipation, high blood pressure, heart palpitations and arrhythmias and insomnia — tired and wired. These are the most common symptoms but there is hardly a disease state that magnesium deficiency isn’t implicated as a causal factor.

Balance is critical to health

To add to the problem, magnesium needs to be in balance with calcium. They have opposite functions — for example calcium contracts muscles, magnesium relaxes muscles. The ideal ratio of calcium to magnesium is thought to be 1:1 to 2:1 so if you’re getting say 800 mg calcium, you’d need 400 – 800 mg magnesium. That’s a whole lot more than 200 mg. Most people’s ratio is 5:1 or higher and that’s a major problem over the long term.

A lot of people take calcium supplements because they believe it’s good for bones. The truth is that calcium supplementation is now clearly understood to have been a serious error. The real culprits in osteoporosis are deficiencies in magnesium and vitamins D and K2. Our diets and lifestyles have become unbalanced, our bodies aren’t getting what they need — not enough sun for example, and the wrong foods, that mean our bodies lose the ability to maintain the best health over the long term.

What troubles me most is the excessive calcium recommendations in the US — above 1000 mg a day for adults, because high calcium is dangerous when magnesium and vitamin K2 is low, and people aren’t stopping at 1000 mg. It’s quite easy to be getting 2000 mg a day with a combination of a dairy rich diet, fortified foods like orange juice and coconut milk, and supplements.

Harvard School of Public Health agree:

“Currently, there’s no good evidence that consuming more than one serving of milk per day in addition to a reasonable diet (which typically provides about 300 milligrams of calcium per day from non-dairy sources) will reduce fracture risk. Because of unresolved concerns about the risk of ovarian and prostate cancer, it may be prudent to avoid higher intakes of dairy products.”

Compare and contrast the US recommendations to the UK (700 mg) and the World Health Organization (WHO) (500 – 700 mg). The high calcium recommendations appear to be a reflection of poor lifestyles, e.g. poor vitamin D status, magnesium deficiency, acid load diet, lack of exercise, high sodium intakes etc, but upping the calcium is not the answer, getting all lifestyle factors working together naturally, is.

It’s calcium balance that is a critical factor for bone health. The acid-base status of the total diet rather than calcium intake or excretion determines calcium balance.1 When the diet has an overall net acidic load, the body breaks down bone as a calcium buffer for blood.2

In a healthy diet where there is a net base load from lots of fruits and vegetables, less calcium is desirable. It seems to me that the UK and WHO recommendations in the context of a healthy lifestyle are about right.

Vitamin D status is a major factor when it comes to calcium needs. People don’t get enough sun and are deficient, but with normal blood levels of 25-hydroxyvitamin D above 30 ng/ml, calcium intakes of 600 mg a day maximize bone health.3 So vitamin D status is far more important for bones than overdosing on calcium, which has negative effects for heart and vascular health. Vitamin D improves calcium absorption by activating calcium-binding proteins in our intestinal cells and regulates the vitamin K2-dependent proteins osteocalcin and matrix gla which are essential to get calcium into bones and out of arteries. So calcium and vitamin D are intimately connected, and calcium needs depend on vitamin D status.

BUT trying to correct vitamin D deficiency in a magnesium deficient state will make matters worse because magnesium is needed in vitamin D metabolism. And without adequate vitamin K2 to get calcium in the right places, it leads to calcification of soft tissues and arteries. The clear answer is to optimize calcium, magnesium, vitamin D and vitamin K2 together.

Getting your ratio right with support from vitamins A, D and K2

All nutrients work synergistically. People with bone health issues need a holistic approach that might look something like this:

  • Net base diet. Lots of fruits and vegetables. Human food.
  • Calcium intake around 700 mg a day. For people who eat some dairy products, this is easy to get from food. E.g. just 1 cup milk and 2 oz Brie (rich in K2) is 380 mg calcium, and will mean overall daily calcium at around 700 mg where we want it. So you see how easy it is to get too much.
  • Magnesium intake 700 mg a day, from a good diet and 300 – 400 mg magnesium supplement — magnesium citrate, glycinate or threonate. I think it’s a good idea to vary the type. Take with meals 2 or 3 times a day e.g. 2 x 200 mg, or 3 x 100 mg.
  • Vitamin A as retinol from animal source foods, also called preformed vitamin A, is very important e.g. for removing excess calcium but needs to be limited for balance e.g. 4 oz liver once a week or liver pâté (I add ½ oz to my salad most days instead of having liver) and pastured eggs. Liver and eggs are also great sources of choline and B12, which most people are deficient in so it’s good to get these in your diet habitually. Vitamin A precursors like carotenoids which your body can convert to retinol come from fruits and vegetables and don’t need to be limited. Don’t take supplements with retinol/preformed vitamin A, or take into account in your overall plan.
  • Vitamin D (actually a hormone) through summer sun exposure, 30 minutes if you have fair skin with as much skin exposed as possible. Darker skin will need longer. Close to noon is best, but between 10 a.m. and 3 p.m. when UVB is strongest. There’s an app called D minder, that estimates how much vitamin D you make outside depending on where you are, skin type, time of year, time of day etc.  In winter, I suggest supplementing vitamin D3 2000 IU a day based on the latest advice from endocrinologist Michael Holick who’s been researching vitamin D for 40 years. Another option for winter, and probably the best one is to use a safe tanning bed, which have electronic ballasts. Ideally, test your blood 25 hydroxy D levels every 3 to 6 months and aim for 40-50 ng/ml (100-125 nmol/l). This appears to be the natural level for humans e.g. the Hadza in Tanzania were tested at 43.6 ng/ml.5 Each 100 IU of oral vitamin D3 raises blood levels by approximately 1 ng/ml. If you have any symptoms of magnesium deficiency when changing your D habits by sun or supplements, like palpitations or anxiety, you need to correct magnesium first.
  • Vitamin K2. Optimal dose hasn’t been established but I suggest 5 mg menaquinone-4 (MK-4, menatetrenone) as an initial therapeutic dose. Vitamin K2 comes in MK-4 and MK-7 forms in supplements, needed to get calcium in the body where it needs to be, in bones and teeth, not arteries, and it protects against vitamin D toxicity. Like magnesium, nearly everyone is deficient, because our eggs and butter and other natural sources are either missing from the diet or come from industrially raised animals not fed on grass. The MK-7 K2 derived from natto can build up in the system in some people and cause heart palpitations. It also stays in the blood longer than MK-4 and some experts believe that’s because the MK-4 K2 is getting into tissues where it needs to be. MK-4 is the form found naturally in the diet in animal products like pastured butter, eggs, liver, and meat. MK-4 is the type used in studies showing great benefit of K2 for bone health — it’s been more thoroughly studied. For these 4 reasons I recommend MK-4. Vitamin K2 supplementation dramatically reduces fracture rates5 and even reverses arterial calcification.6 I’ve even read reports of varicose veins disappearing with K2 supplementation. I like Thorne Research MK-4 drops — each drop has 1 mg MK-4. 1 mg a few times a week seems like a good maintenance dose.
  • Exercise. Stressed bones get stronger.
  • Homemade bone broth if you have the time and inclination, to use in sauces, soups and stews — rich in collagen and extracellular matrix. What I do is use the bones from roast chicken, in a pot with carrot, onion, celery, sea salt and pepper. Boil for 2-6 hours (6 is best) making sure the bones and veg are covered at all times. Strain and freeze in ice cube trays, then put the cubes in a bag to save freezer space. Then you have real “stock cubes” to make a quick sauce with butter and garlic, add to stews etc. If you want to go the extra mile, you can get bones and joints from your butcher.

And really, it’s going to be a similar program for everyone, because we want to prevent bone problems, and calcium and magnesium are not only about bones, they are involved in countless biochemical functions. Understanding the synergy of nutrients is the answer to the calcium paradox, the fact that people in developing countries and Asia, where calcium intakes are low, have low rates of osteoporosis. The fact is that other factors in their lifestyles are protecting them, like plenty of sunshine or traditional use of fermented foods like natto that provide lots of vitamin K2. It was never just about calcium.

The diet in Happy Guide will typically give you 350 to 450 mg magnesium a day for 2000 to 2500 calorie intakes. If you’re not stressed, or have any other lifestyle depleters of magnesium, and you limit dairy to the recommended types and get roughly the right amount of calcium, all is well.

BUT if you’re currently not having an optimal diet, exercising hard, stressed, OR have any symptoms of magnesium deficiency, then I recommend taking 200 to 400 mg a day of magnesium in the citrate or chelated form.

For chronic health issues, test and optimize

If you have chronic health issues, it’s imperative to get this right. I recommend tracking your diet on Cronometer and see how much calcium and magnesium you are getting. Some types of dairy like milk, yogurt and cheese are very rich in calcium and it doesn’t take that much to push your intake way too high. It’s also a good idea to test your 25 hydroxy D levels and get a magnesium RBC test every 3 months and optimize. Optimal vitamin D levels to aim for are 40-50 ng/ml (100-125 nmol/l) and optimal magnesium RBC is 6.0 – 6.5 mg/dl in a normal range of 4.2 – 6.8 mg/dl.

For everyone

I like to get and recommend all nutrients from food, but I think magnesium is a special case. Most people will benefit from a 200 mg insurance of magnesium a day. That’s my current thinking. So say you normally have around 2000 calories, and shoot for 700 mg calcium a day, then you’d be getting around 350 mg magnesium on a healthy diet plus 200 mg supplement. 700 mg Ca : 550 mg Mg. These numbers feel very good to me for the long term.

Magnesium is certainly one nutrient we need to be aware of because it’s so important to get right, and get in balance with calcium, A, D and K2, and of course everything else, because everything affects everything else.


  • If you have kidney disease, be sure to talk to your healthcare provider before taking magnesium supplements.
  • If you are taking Warfarin, please click here to read about Warfarin and vitamin K, and talk to your healthcare provider before altering your vitamin K2 (or vitamin K1) habits.
  • All data in this article refers to adults not pregnant or breast-feeding.


1. Barzel US. The skeleton as an ion exchange: implications for the role of acid-base imbalance in the genesis of osteoporosis. J Bone Miner Res. 1995; 10: 1431-36

2. Barzel US, Massey LK Excess dietary protein can adversely affect bone. J Nutr 1998; 128:1051-53

3. Bischoff-Ferrari HA et al. Dietary calcium and serum 25-hydroxyvitamin D status in relation to BMD among U.S. adults. Journal of Bone and Mineral Research 2009 May;24(5):935–42. doi:10.1359/jbmr.081242

4. Luxwolda MF et al. Traditionally living populations in East Africa have a mean serum 25-hydroxyvitamin D concentration of 115 nmol/l. British Journal of Nutrition 2012 Jan 23:1–5, [epub ahead of print]. doi:10.1017/S0007114511007161

5. Cockayne S et al. Vitamin K and the prevention of fractures: systematic review and meta-analysis of randomized controlled trials. Archives of Internal Medicine 2006 Jun 26;166(12):1256–61,

6. Schurgers LJ et al. Regression of warfarin-induced medial elastocalcinosis by high intake of vitamin K in rats. Blood 2007 Apr 1;109(7):2823–31,

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Michael Kinnaird is the author of Happy Guide, the result of a 20 year exploration into what works for health and happiness.

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