Low levels of magnesium and osteoporosis are linked - the evidence proves it. Although magnesium is not typically one of the minerals we hear about (like calcium and Vitamin D)
in discussions of osteoporosis, it turns out that magnesium is very important in helping to prevent this disease. So, what exactly is this relationship between magnesium and
osteoporosis all about?
Magnesium is a chemical element and one of the basic building blocks of matter. It is a soft, silvery-white alkaline earth metal, in the same chemical family as calcium and strontium (to learn more about these two elements, both of which play major roles in bone health, please refer to my pages on calcium and osteoporosis and strontium for osteoporosis). Magnesium is the fourth most common mineral in our bodies, and is found in compounds that comprise the earth's crust. Weathering of the earth's crust releases these magnesium compounds into the soil. Many plants then readily absorb these compounds from the soil - when we consume these magnesium-containing plants, our digestive systems absorb the mineral for use by our bodies.
The majority of magnesium in our bodies is stored in our bones (somewhere between 50 and 67%), with a small amount present in our blood (about 1%) and the rest stored in our cells. Magnesium is important to many cellular functions and is vital to proper functioning of our nerves, muscles and heart. It also makes our bones strong when incorporated into our bone structure (along with much larger amounts of calcium and phosphorus). Although it is only a small portion of our bone content (approximately 1%), it is vital. It appears to improve the quality and density of the bone matrix. If the content of magnesium in our bones gets too low, we end up with brittle bones - and brittle bones are more susceptible to fracture.
A number of studies have been done in an attempt to understand what role magnesium plays in healthy bone formation. Below are three such studies:
Although the cause (low magnesium intake) and effect (resulting in low levels of calcitriol) was implied in several studies, I could not find a satisfactory explanation for the mechanism by which it occurs (if I do, I'll update this). I'll admit that there does not appear to be conclusive evidence that a magnesium deficiency directly causes lower production of the biologically active form of Vitamin D (calcitriol).
There does appear, however, to be sufficient evidence that low magnesium levels in turn lower parathyroid hormone levels. Parathyroid hormone controls calcium levels in the blood by several different mechanisms, one of which is activating calcitriol formation in the kidneys. And, since calcitriol is critical to absorption of calcium, low levels of it due to a magnesium deficiency would adversely affect the amount of calcium available for building healthy bones. Make sense?
The role magnesium plays in preventing and treating osteoporosis is complicated - and not completely understood. But, based on studies that have been done, it appears that an adequate daily intake of magnesium is important in reducing the incidence of osteoporosis.
For adults, the USDA recommended daily allowance for men over the age of 31 is 420mg. For women the same age it's 320mg. Most people, especially those of us who live in the western countries, simply are not getting these amounts through diet (4). Our ancestors consumed far more whole grains than we do, and got much of their daily requirement for magnesium.
Sadly, the grains consumed today are highly refined. This refining process strips the outer hull off the grain, where many nutrients, including magnesium are stored. Additionally, most of us today just don't eat as many magnesium-containing foods, especially fresh green vegetables, as our ancestors did. To read so much more about healthy eating, please check out my healthy eating guidelines!
Okay, so the magnesium and osteoporosis connection is real. So, what can you do to ensure you get enough magnesium to lower your chances of getting osteoporosis? Eat a healthy diet which includes the following magnesium-rich foods (magnesium is also found in drinking water, but content varies greatly from city to city).
For most of us, just eating a varied diet high in whole grains, nuts and green vegetables will give us enough magnesium. But, for people with osteoporosis risk factors (post-menopausal women, men over 65, and anyone with secondary osteoporosis risk factors), supplementation with magnesium may be beneficial. If you are in one of these higher risk groups, discussing magnesium supplementation with your health care provider may be worthwhile. The link between low levels of magnesium and osteoporosis should be taken seriously!
If you're already consuming a diet high in (or supplementing with) calcium, something to consider is the best calcium to magnesium ratio. Some experts believe that ingesting too
much calcium relative to magnesium will lead to calcium being deposited in unwanted areas, such as joints and organs, leading to other health issues.
Some experts say that the correct ratio of calcium to magnesium is 1:1. They firmly believe that this is the ratio that was present in our ancient ancestors' diets. Another group of experts believe that a 2:1 calcium to magnesium ratio is best. Our modern diets tend to be higher in calcium yet lower in magnesium than our ancestors'. People taking calcium supplements for osteoporosis, and not getting adequate magnesium, may have ratios as high as 15:1!
Based on a calcium to magnesium ratio of 2:1, if you take 1,200mg of calcium, then 600mg of magnesium would be appropriate. There is no need to take higher dosages of magnesium - and be forewarned that magnesium acts as a laxative (think Milk of Magnesia)!
Magnesium is critical to good overall health. And the link between low levels of magnesium and osteoporosis is strong. For me, that's enough to convince me that eating magnesium-rich foods is a critical part of nutrition for osteoporosis prevention. For optimal health, as well as osteoporosis prevention, healthy eating and healthy exercise go a long way!

References:
Return from Magnesium and Osteoporosis to Natural Treatment for Osteoporosis.
Strontium for Osteoporosis - An Effective Osteoporosis Treatment.
Strontium Supplements - The Best Information On Treating Osteoporosis With Natural Strontium!
Strontium Ranelate - An Alternative Treatment for Osteoporosis.
Calcium and Osteoporosis - Learn How Calcium Affects Your Bones.
Supplements for Osteoporosis - Calcium and Vitamin D Supplements are Vital To Bone Health!
The Vitamin D Osteoporosis Connection - What You Need To Know About How Vitamin D Affects Your Bones.
Whole Body Vibration Therapy. - An Effective Natural Treatment for Osteoporosis!
Return from Magnesium and Osteoporosis to Natural Treatment for Osteoporosis.