Move Over Calcium—Here Comes Magnesium for Bone Health
Everybody knows by now that calcium is one of the most important building blocks of our bones and teeth. It’s well established that bones need calcium. After all, the bone remodeling process continually removes small amounts of calcium from bones that then need to be replaced with new calcium. While calcium is important, nonetheless, our bones are made up of many more components other than calcium. A very important one is and people are often deficient. Most of the magnesium in the body is actually found in bones (approximately 60%).
We also know that bone health relies heavily on which helps regulate calcium and phosphate balance to maintain healthy bone function. But guess what? Magnesium is needed to activate vitamin D. Calcium, magnesium and vitamin D all work together to support . Calcium homeostasis is regulated in part by magnesium.
When it comes to calcium and in the human body, it’s like a dance. The key is to make sure neither one is stepping on the other one’s toes! As with any good dance, it’s all about balance. When the ratio is right between these two, there is physiological harmony. But when the ratio is off, the process may fall out of step.
Studies have found that calcium directly or indirectly competes with magnesium for intestinal absorption and transport, especially if calcium intake is much higher than magnesium intake. For example, if the gut has more magnesium than calcium, the magnesium will be absorbed but if there is a much higher amount of calcium, the magnesium will not be absorbed. This is big information with a big impact. High dose calcium supplementation is common, and we also know the dramatic necessity of adequate magnesium for optimal physiological function.
In a 1997 study published in the American Journal of Clinical Nutrition, children who consumed even the Recommended Dietary Allowance of magnesium were in negative magnesium balance if their calcium intake was high. The body of current evidence supports taking more frequent, lower doses of calcium (with meals if using calcium carbonate), and avoiding high doses above 250 mg at a time. If you take magnesium supplements separately, take them at a different time than your calcium supplements, for example, just before bed. This helps ensure both better magnesium absorption, and calcium absorption.
A 2013 population-based cohort based on the Shanghai Women’s Health Study and the Shanghai Men’s Health Study that was published in the journal BMJ Open eloquently illustrated that the amount of calcium and magnesium absorbed is dependent on the dietary ratio of calcium to magnesium. The two Shanghai studies that were featured in the cohort took place over a four-year period involving nearly 75,000 women and more than 61,000 men ages 40 to 74. Calcium and magnesium intake was validated by food questionnaires and the follow-up rate for both of these studies was nearly 100%.
This 2013 BMJ Open study clearly demonstrated that calcium intake alone was not nearly as important as the calcium to magnesium ratio. The calcium to magnesium intake ratio among this Chinese population was on average 1.7 versus approximately 3.0 in the United States. In this study, intakes of magnesium greater than the US RDA of 320 mg/day for women and 420 mg/day for men was associated with poor health. Poor health was also associated with a calcium to magnesium ratio of greater than 1.7 for the men and greater than or equal to 1.7 for the women. Because this study was done on a population with a lower calcium to magnesium ratio compared to the United States, we are not sure how this can be applied to US populations. However, it does illustrate the importance of striking in both food and dietary supplements in clinical practice.
According to the Nutritional Magnesium Association, the 2:1 calcium-to-magnesium ratio was first discussed by French magnesium researcher Jean Durlach in an effort to help prevent excessive calcium intake, which can damage health. “It is important to note that this ratio is for weights of elemental calcium and elemental magnesium, not the weights of their compounds,” stresses the Nutritional Magnesium Association. “It is also for all sources of calcium and magnesium intakes including food, water and supplements.”
In dietary supplements the ratio of calcium to magnesium can vary with some manufacturers having an approximate 2:1 ratio and some having a 1:1 ratio. Practitioners typically have a preference of products they recommended based on the patients they are treating. But more practitioners are now choosing to dose calcium and magnesium separately, for optimal absorption of each. Especially since calcium may interact with certain medications, thyroid replacement for example, magnesium can be dosed in the morning and calcium later in the day, reducing the competition for absorption.
In light of the body of research, now is a good time for all practitioners to re-examine their own beliefs and practices regarding calcium and magnesium supplementation, especially with regard to bone and heart health. High doses may do more harm than good. More is not better. Dietary intake is not insignificant – it must be assessed and considered before supplementation. Medication interactions must be considered to determine timing of dosing. And, they don’t need to be taken together at the same time. But, with a little extra effort, maintaining a physiologically healthy, 2:1 ratio of daily calcium intake to magnesium intake overall, is a very attainable goal.