magnesium and vitamin D

This is Why You Should Take Magnesium and Vitamin D Together

Magnesium is an important mineral for your health and metabolism. The role of magnesium on vitamin D metabolism has been largely studied.

Vitamin D deficiency is usually approached simply by vitamin D supplementation, but this will be a total 'nonsense' if your magnesium levels are not enough.

Why should you take magnesium and vitamin D together?

Scroll down to find out!!

Why is Magnesium Important?

Magnesium is the fourth most abundant minerals in your body.

Your body contains near 25g magnesium, out of 99% is stored in bone, muscle and non-muscular tissue (study). The other 1% is found in serum and red blood cell, in where there are three categories of magnesium; free/ionized, protein bound and complexed with anions.

Magnesium shows the highest bioavailability when complexed with anions (study)

Magnesium Distribution

Importance of Magnesium on the metabolism

Magnesium plays important roles in our metabolism and health. It acts in more than 300 reactions, playing a big role on your survival and development.

Magnesium is present in some of the most important metabolic reactions such as glycolytic pathway, protein synthesis, or the processes forming the Central Dogma (study).


Magnesium Acts as Cofactor for Biological Reactions

Due to its biochemical properties and electric charge (2+), magnesium helps stabilize enzyme complexes.

By stabilizing the enzyme complex, magnesium allows the reaction to proceed efficiently (study).

Certain enzymes need of a magnesium molecule in order to catalyse the reaction.

Analogy for Magnesium stabilization:

Think of a magnet being attracted by another magnet of opposite pole. In biochemistry, negative and positive charges attract each other by the called ionic interactions and other weak non-covalent interactions. The formation of these interactions will help stabilizing the complex under physiological conditions (study)

Magnesium Maintains Body Homeostasis

Magnesium regulates osmotic gradients (study).

This osmosis and water movement through internal tissues is crucial for maintaining a good cell environment and maintain pH levels in range for efficient metabolic rate (study)

magnesium meme

Magnesium Regulates Muscle Function

Magnesium has been linked to Ca2+ transport in/out the sarcoplasmic reticulum (study). Calcium will regulate muscle contraction (study).

Magnesium increases oxygen uptake and delivery on muscle cells. This will benefit muscle cell respiration and aerobic exercise (study). Magnesium also acts directly with muscle, enhancing nerve cells function and muscle contraction (study).

Its role as a cofactor will also optimize and enhance the glycolitic pathway, leading to a more efficient ATP production (study)

Functions of Magnesium

The Relation between Magnesium and Vitamin D

Vitamin D metabolism refers to the different biochemical conversions to form the active vitamin D molecule and following washout.

The efficiency of these conversions will determine how Vitamin D can help you improve your health.

Magnesium is a cofactor in almost all reactions involved in vitamin D metabolism (study).

Deficiency of magnesium may decrease the eficiency of vitamin D metabolism.

Vitamin D supplementation is not effective if you are magnesium deficient.

Magnesium and Vitamin D metabolism

Overview of the Vitamin D Metabolism

Vitamin D is synthesized from 7-dehydrocholesterol and UVB radiation (sunlight).

That forms an inactive prohormone, provitamin D3, which converts in vitamin D3 by means of temperature stabilization.

Once in your body, it's transported by VDBP through the plasma to the liver.


In the liver, vitamin D forms 25(OH)D, and it is transported by VDBP to the kidney, where its's converted to 1,25(OH)2D, the active form.

Vitamin D washout takes place in the liver. To be removed through urine, 1,25(OH)2D is converted into 1,24,25(OH)3D. Similarly, 25(OH)D can be converted to 24,25(OH)D for vitamin D washout.

Vitamin D Metabolism

  1. Synthesis from 7-dehydrocholesterol
  2. Transport by VDBP to the liver
  3. Conversion to 25(OH)D
  4. Transport by VDBP to the kidneys
  5. Conversion to 1,25(OH)2D or 24,25(OH)2D
  6. Conversion to 1,24,25(OH)3D for washout

Magnesium on Vitamin D Metabolism

Magnesium is required in almost all reactions of vitamin D metabolism (study). The reactions in where Magnesium needs to be present are:

  • Conversion of vitamin D3 to 25(OH)D
  • Conversion of 25(OH)D to 1,25(OH)2
  • Conversion of 25(OH)D to 24,25(OH)2D
  • Conversion of 1,25(OH)2D to 1,24,25(OH)3D
  • Conversion of 24,25(OH)2D to 1,24,25(OH)3D

Magnesium is also needed for the synthesis of VDBP (study) and synthesis and secretion of parathyroid hormone.

These two molecules regulate the activity of the enzyme catalysing the conversion of 25(OH)D into 1,25(OH)2D, the active form of vitamin D (study).


Vitamin D on Magnesium Metabolism

Vitamin D also affects magnesium metabolism.

This interplay between vitamin D and magnesium regulate your metabolism and lower the risk of breaking body homeostasis.

Vitamin D  improves intestinal absorption of magnesium by nearly 30% (study), while maintaining retention of magnesium constant (study).


Vitamin D serum levels  affects magnesium metabolism. Vitamin D deficiency can lead to inefficient magnesium metabolism.

Combined supplementation of vitamin D and magnesium can prevent deficiencies of any of these substances.

How to Supplement with Magnesium and Vitamin-D

Magnesium influences vitamin D metabolism by acting as a cofactor in all conversions to get the active form and washout of vitamin D. Not only that, but it's also required for the synthesis of VDBP and Parathyroid Hormone.

On the other hand, Vitamin D improves intestinal absorption of magnesium and the retention in your organism.

But what doses do you need of each to prevent deficiencies?


Vitamin D Supplementation

Vitamin D supplementation is the most efficient way to avoid deficiency.

Due to limited sun exposure and low content on dietary sources, supplementation is the only way to achieve high doses of vitamin D.

There´s a wide range of doses being used in research and clinical uses:

  • Doses of 1500-3000 UI/day were more effective than lower dosis at increasing magnesium absorption (study).
  • When it comes to avoiding vitamin D deficiency, however, doses ranging from 1000 to 4000UI are used (study).

For now, 2000-4000UI seem to be appropriate and effective at both improving magnesium absorption and increasing vitamin D serum levels.

Timing of Vitamin D

Vitamin D in the morning could bring you extra benefits. It may help you regulate your Circadian Rhythms by simulating sunlight exposure.

However, it is more important to make sure you take vitamin D, than trying to optimize it by taking it in the morning... first comes first!

circadian rhythms

Magnesium Supplementation

The recommended Magnesium serum levels lay between 0.75-0.95mmol/L(study).

Eating magnesium-rich foods can help you achieve those levels. These include spinach, seeds, nuts, cocoa, whole grains, avocado, potato, rice and salmon.

However, human hand on different foods has lowered the magnesium content by nearly 80% (study). This increases the risk of hypomagnesemia, and magnesium supplementation could be the solution.

Official institutions recommend 400-420mg and 310-320mg for men and women (source).

Doses of 200-400mg magnesium oxide increases magnesium serum levels.

Types of Magnesium Supplements

There are different formulations for magnesium supplements.

With different pharmacokinetics and bioavailability, it's important that you choose the right one.

Inorganic formulations have a higher content of essential magnesium, but lower bioavailability. Organic salts of magnesium, contain less essential magnesium, but with a higher bioavailability (study).

Magnesium oxide seems to be the best formulation to increase magnesium serum levels and avoid deficiency(study)


Combined Supplementation

Combined Vitamin and Magnesium supplements are rare.

With different biochemical properties, solubility and pharmacokinetics, it is a big challenge to formulate this supplement.

This supplement provides the right doses of magnesium and vitamin D to prevent deficiencies and increase serum levels.


Magnesium and Vitamin D influence each other to potentiate the other's action. While magnesium is required for all conversion on vitamin D metabolism, vitamin D increases magnesium absorption and retention in our body.

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