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Magnesium optimizes the level and effect of vitamin D

Magnesium optimizes the level and effect of vitamin DWe need plenty of vitamin D for our bones and immune defense, for preventing cancer and so on, but if we lack magnesium, vitamin D does not work as expected. This is because magnesium is needed for activating vitamin D and enabling it to benefit the body’s cells and tissues. Magnesium also regulates blood levels of vitamin D, more specifically by increasing them if they are too low and lowering them if they are too high. This was demonstrated in a recent study from Vanderbilt University, the United States. The scientists call this highly important information, as there has been conflicting results from studies that compared blood levels of vitamin D in relation to colon cancer and various other diseases. Because magnesium deficiency is a widespread and overlooked problem, there is reason to believe that many people have difficulty with regulating levels of vitamin D in their blood. Also, they risk that their vitamin D does not have the desired effect in terms of preventing a host of different diseases.

It turns out that vitamin D and magnesium work closely together, which is of vital importance in the prevention of osteoporosis, infections, cancer, and a host of other diseases. It is therefore crucial to get the right amount of the two nutrients and in the right balance. The new randomized study from Vanderbilt University Cancer Center studied 250 people at increased risk of developing colon cancer because of having a high-risk adenoma (polyp) removed or showing signs of other risk factors. It is already known that lack of vitamin D increases the risk of colon cancer, and the scientists therefore wanted to look at magnesium’s role.
The new study confirmed an earlier study that had linked low magnesium levels with low levels of vitamin D. As something entirely new, the study showed that magnesium has the potential to optimize levels of vitamin D in people with low levels of the nutrient and lower levels in people, who have high vitamin D levels.

Lack of magnesium inhibits the effect of vitamin D

According to Professor Qi Dai, who headed the study, the ideal blood level of vitamin D for preventing cardiovascular disease lies somewhere between the minimum and maximum reference intake level. Nonetheless, studies like the VITAL study (Vitamin D and Omega-3 trial) failed to show a link between vitamin D and cardiovascular disease, and there is reason to believe that magnesium may explain the conflicting study results. The scientists from Vanderbilt University set out to study what role magnesium combined with vitamin D plays in the prevention of colon cancer. The researchers suddenly became interested in magnesium’s role because they discovered that people synthesize vitamin D differently, and in some individuals, levels of the nutrient do not increase even if they are given high-dosed supplements.

Lack of vitamin D and magnesium is rather common

The scientist behind the new study explain that lack of vitamin D has been recognized as a serious health problem in the United States, and many people are advised to take a vitamin D supplement to raise their blood levels of the nutrient. However, this is no guarantee that they are able to utilize the vitamin. Magnesium deficiencies are underestimated, and the researchers point to the fact that as much as 80 percent of the American population fails to get the recommended amount of magnesium from the diet. In light of this, there was a widespread magnesium deficiency among the participants in the new study. The scientists therefore advised the study participants to increase their intake of magnesium-containing foods such as broccoli and other green vegetables, beans, whole grain, oily fish, avocado, and dark chocolate.

Lack of vitamin D is also rather common in Denmark, and many people take vitamin D supplements in the winter period to prevent influenza and other diseases. A vitamin D supplement does not work optimally, however, unless you have enough magnesium in your blood.

How magnesium activates vitamin D

The sun is our primary source of vitamin D, but it is only during the summer period that the sun sits sufficiently high in the sky to allow us to synthesize vitamin D in our skin. The first step in the synthesis is that we produce a prohormone called cholecalciferol, which is converted into 25-hydroxycholecalciferol D3 in our liver by means of magnesium-containing enzymes. This is the form of vitamin D that is measured in the blood
When the body needs vitamin D, a parathyroid hormone converts vitamin D into 25-dihydroxycholecalcifrerol D3 in our kidneys with help from other magnesium-containing enzymes.

Source Type of vitamin D and enzyme activity
Diet and supplements Cholecalciferol
Skin Cholecalciferol
Synthesized from 7-dihydroxycholesterol and UVB rays from the sun
Liver 25-hydroxycholecalciferol D3
Made with help from the enzyme 25-hydroxylase
(requires magnesium)
Kidneys 1,25-dihydroxycholecalciferol D3
Made with help from the enzyme 1-alfa-hydroxylase
(requires magnesium)

Why magnesium deficiency is so common

Lack of magnesium is a result of many things, including modern farming methods and eating a diet that is not very balanced and contains too many refined foods. A large consumption of alcohol and other stimulants, taking birth control pills, using diuretics and antacids, engaging in intensive training, and being stressed can also inhibit the body’s magnesium uptake or deplete levels of the essential mineral.
Insulin resistance and type 2 diabetes can also leech the body’s magnesium stores, and it is often a combination of the different factors that has a reinforcing impact. For that reason, our magnesium requirement may very well be larger than the recommended intake level.

Magnesium measurements are often misleading

It is rather difficult to measure the body’s magnesium status, as only approximately 1% of the body’s magnesium is found in the blood. The most accurate way of measuring magnesium levels is a so-called whole blood analysis that also measures magnesium inside the blood cells. Still, this does not take into account that 60% of our magnesium is stored in bone tissue.


Qi Dai et al. Magnesium status and supplementation influence vitamin D status and metabolism; results from a randomized trial. The American Journal of Clinical Nutrition 2018

Vanderbilt University Medical Center. Magnesium optimizes vitamin D status, study shows. ScienceDaily 2018

Anne Marie Uwitonze, Mohammed S Razzaque. Role of magnesium in Vitamin D Activation and Function. The Journal of the American Osteopathic Association. 2018

American Osteopathic Association. Low magnesium levels make D-vitamin ineffective. ScienceDaily. 2018

Mario Barbagallo and Ligia j Dominquez. Magnesium and type 2 diabetes. World Journal Diabetes. 2015

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