Vitamin D and Magnesium

The Most Important Co-factor For Vitamin D

Sure, vitamin D is a miracle nutrient, but what if we are missing an essential component that allows vitamin D to work its miracles?

Vitamin D

In 2008, as vitamin D research was kicking up, Dr.Cedric Garland, professor of preventive medicine at the University of California, San Diego, publicly stated, “I think vitamin D is introducing a golden age in medicine.” (Source)

Yet, to this day vitamin D deficiency is still a global health concern, as it has been determined to be an independent risk factor for overall mortality: “Our study supports a causal relationship between vitamin D deficiency and mortality. Additional research needs to identify strategies that meet the National Academy of Medicine’s guideline of greater than 50 nmol/L and that reduce the premature risk for death associated with low vitamin D levels.”   (Source)

In my endless blogs and newsletters on the subject of vitamin D, I have made it abundantly clear that having adequate vitamin D is the single most important thing we can ensure in order to live long and healthfully. Aside from vitamin D deficiency being linked to “diseases affecting the cardiovascular system, musculoskeletal system, and nervous system”, almost virtually any ailment or disease that you can think of has some relationship to vitamin D.

The sad thing is that on a regular basis I consult with people who are still only taking 1,000 IU of vitamin D daily. But, for my readers I’m sure this is not an issue; you are all well educated in the importance of vitamin D and most likely supplementing with a reasonable amount (I personally take 25,000 IU weekly, sometimes more if fighting a cold or flu, or feeling under the weather duing the winter).

When we make vitamin D in our skin, from sunlight exposure, or when we get it from food or natural supplements (D3 – cholecalciferol), it is in what is known as an “inactive” form.

“Vitamin D needs to be converted from its storage or inactive form (25[OH]D) to an active form (1,25[OH]2D) before exerting its biological functions. These various stages of vitamin D conversions are actively dependent on the bioavailability of magnesium.”

It has now become obvious to the scientific community that the endless health benefits of vitamin D, whether earned from sun-exposure or consumed in supplement form, is absolutely dependent on us having an adequate presence of magnesium in our body.


Magnesium is the fourth most common mineral in our bodies, after calcium, potassium and sodium. Essential for cell function stability and repair, and for RNA and DNA synthesis, magnesium also activates more than 300 enzymes and is required for regulating extracellular calcium levels. Bones, heart, skeletal muscles, teeth, and many of the organs rely on adequate magnesium to fullfill their biological functions properly. And this is just scratching the surface, as it has many other critical functions as well.

Unfortunately, like the widespread deficiency in vitamin D, magnesium deficiency is also quite common.

The magnesium consumption from natural foods has decreased in the past few decades, owing to industrialized agriculture and changes in dietary habits. The standard diet in the United States contains about 50% of the recommended daily allowance (RDA) for magnesium, and as much as three-quarters of the total population is estimated to be consuming a magnesium-deficient diet.

Those of us familiar with how vitamins, minerals, and other nutrients work, know that each individual nutrient requires certain cofactors for its absorption and utilization in the body. Zinc requires copper, calcium requires magnesium, single B-vitamins require that we take the other B-vitamins, vitamin E works better in the presence of selenium, iron requires vitamin A and copper in order to be stored as ferritin, etc. And, vitamin D requires that we have vitamin K2 and vitamin A available, but it appears that magnesium is the most important cofactor for vitamin D.

Magnesium assists in the activation of vitamin D, which helps regulate calcium and phosphate homeostasis to influence the growth and maintenance of bones. All of the enzymes that metabolize vitamin D seem to require magnesium, which acts as a cofactor in the enzymatic reactions in the liver and kidneys. It is therefore essential to ensure that the recommended amount of magnesium is consumed to obtain the optimal benefits of vitamin D.


In one study, 126 patients with type 2 diabetes (both men and women with an average age of 53) had their vitamin D and magnesium levels analyzed. Patients were given 2,000 IU of vitamin D3 for 6 months, and “a significant increase in serum levels of magnesium was found after they consumed vitamin D3 supplements”.

Other studies have found that the increase in mortality from vitamin D deficiency could be favorably altered simply by giving the subjects magnesium. In one telling study, giving a magnesium supplement to patients with rickets  “markedly reversed the resistance to vitamin D treatment”.

This link between vitamin D and magnesium is so solid that simply having a high intake of magnesium, “reduced the risks of vitamin D deficiency or insufficiency in the general population”.

When we examine mortality rates due to cardiovascular diseases, we find that the disease rates are reduced when subjects have an intake of magnesium that is above the average (from food or supplements).

No surprise there, as magnesium is essential to maintain a healthy heart: “it helps stabilize the rhythm of the heart and plays a role in preventing abnormal blood clotting in the heart. Magnesium also helps maintain healthy blood pressure levels, and studies have found that magnesium is highly effective in reducing the rate of heart attacks and strokes.”

The point here is that the association of vitamin D deficiency with increased risk of cardiovascular disease may be in part due to its relationship with magnesium.  Many studies have been done on providing supplemental calcium and vitamin D for the prevention of osteoporosis, many with mixed results. However, it has been clearly shown that dietary magnesium intake has a positive effect on bone mineral density.

One study showed “that persons who consumed the highest amount of magnesium (420 mg for males and 320 mg for females) had higher bone density and lower risk of osteoporosis. In a study conducted on a small number of osteoporotic postmenopausal women, biochemical features of suppressed bone turnover were seen in women who consumed oral magnesium citrate for 30 days.”


Magnesium is an essential cofactor for the synthesis and activation of vitamin D in our bodies, and a lack in either of these nutrients is “associated with various disorders, including skeletal deformities, cardiovascular disorders, and metabolic syndrome”.

(Source for above material: Role of Magnesium in Vitamin D Activation and Function)

Now, how much magnesium do we require?

“The Recommended Dietary Allowance (RDA) for adults 19-51+ years is 400-420 mg daily for men and 310-320 mg for women. Pregnancy requires about 350-360 mg daily.” (Source)

In our diet we find good amounts of magnesium in dark green leafy vegetables, legumes, nuts, seeds, and whole grains. It is also found in animal foods like beef, fish, and poultry, with the highest amounts found in “anchovy, crab meat, canned tuna, trout, turkey, chicken breast, chicken, salmon, pork and shrimp”.   (Source)

So, if you have a good, balanced diet that favors whole foods, I suggest taking only about 200 mg of elemental magnesium daily (an amount found in our NutriPods and Mineral Mix products).

If you have a less-than-ideal diet, I recommend one ingest about 400 mg of magnesium daily. Remember that, in most cases, anything over 300 mg of elemental magnesium at one time, or anything over 600 mg per day, may induce a laxative effect. The form of magnesium least likely to have a laxative effect is magnesium bisglycinate, and the form most likely is magnesium oxide. If one needs a laxative effect then magnesium is a safe, non-habit forming way to get this response.

For those showing symptoms of magnesium deficiency, such as leg cramps or “Charlie horses”, high blood pressure, migaines, irregular heart beat, sleep disorders, high stress levels, etc, I would suggest taking 300 mg of magnesium twice daily.

(As a related aside, read your labels when buying magnesium, particularly magnesium bisglycinate. Any product that claims to provide 200 mg of elemental magnesium per capsule in the byglycinate form, is always cut with a cheaper magnesium, usually oxide. The maxium amount of magnesium bisglycinate that can be fit into one capsule is 130 mg. If your product does contain oxide, it is important that it be taken at a meal so that it can be properly digested.)

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