There is a good chance that you are taking vitamin D supplements. And if you have been diagnosed with a deficiency, it is typical most doctors prescribe dosages that are too high to effectively correct the issue. This over-prescription can then cause other health issues.
Vitamin D is good for your bones, but your calcium intake is useless if you have no vitamin D to help your body absorb it. Vitamin D deficiency causes joint pain, muscle weakness and fatigue among other symptoms. ideally, these symptoms should go away once you start taking your supplements, but what if they don’t? What if your vitamin D levels still come low on your blood test? Could it be an absorption issue?
Well, most experts recommend vitamin D without sparing a thought for magnesium, a mineral that is required for vitamin D activation and absorption. This is the reason why your vitamin D supplements, when taken without magnesium, may be causing harm rather than improving your bones, joints and muscle health.
Magnesium in Vitamin D metabolism
You need healthy amounts of Vitamin D to absorb calcium and phosphorus from the intestines. This is how it contributes towards building strong, healthy bones and muscles. Lack of vitamin D will lead to reduced bone mineral density that causes rickets in children and osteoporosis in adults. Osteoporosis is marked by weak, brittle bones that are prone to fracture.
It is now a well-known fact that we need vitamin D to prevent weak bones and improve symptoms like fatigue, muscle aches and joint pain. But what needs to be highlighted is that you also need magnesium to correctly use the vitamin D that your body is synthesising from sunlight or getting from supplements. This is not surprising as most nutrients don’t work in isolation. You need one to either make or activate the other. The iron and vitamin C partnership is a classic example of this. Another common example, of course, is the relationship between calcium and vitamin D.
So, how does the magnesium and vitamin D relationship work?
Magnesium is an important co-factor that makes hundreds and hundreds of biochemical reactions in the body. It activates more than 600 enzyme systems that are involved in carrying out these reactions and processes. We will discuss its overall functions and health benefits later in this blog, but first let’s look at its role in vitamin D metabolism.
Vitamin D is stored in an inactive form (25[OH]D) and it needs to be converted into an active form, called calcitriol (1,25[OH]2D) before your body can use it. It is the calcitriol that exerts all its biological functions. Now, you need magnesium to convert stored or inactive vitamin D into its active form. If not for magnesium, vitamin D would simply remain stored or inactive. In other words, your cells won’t be able to use vitamin D despite its abundance.
Magnesium also activates enzymes that are involved in vitamin D metabolism. Magnesium works as an essential co-factor in the enzymatic reactions in the liver and kidneys.
A 2018 study published in The Journal of the American Osteopathic Association showed that vitamin D is not effective in those with low magnesium status. The conclusion was that “Deficiency in either of these nutrients is reported to be associated with various disorders, such as skeletal deformities, cardiovascular diseases, and metabolic syndrome. It is therefore essential to ensure that the recommended amount of magnesium is consumed to obtain the optimal benefits of vitamin D.” 
Mohammad S. Razzaque, the co-author of this study, said that vitamin D without magnesium is not useful or even safe. Razzaque further explains vitamin D supplements can still increase a person’s level of calcium and phosphorus, which can lead to calcification in the blood vessels in the absence of enough magnesium. 
In fact, magnesium is an independent player when it comes to bone health. It is true that it helps in proper absorption and utilization of the sunshine vitamin. But studies show that magnesium also employs other mechanisms to maintain your bone health and even prevent the risk of fractures in the elderly.
More than half of the total magnesium in your body remains stored in bone tissue. This makes sense given magnesium is directly involved in bone formation. It increases the activity of osteoblasts - specialized cells that build bones.
Magnesium also regulates the levels of calcium in the body. When calcium levels rise in the bloodstream, magnesium triggers the thyroid gland to release calcitonin, a hormone that preserves bone structure and integrity. What calcitonin does is that it extracts excess calcium from the blood and soft tissues – and redirects it to the bones. This helps improve mineral density of the bones. You don’t want excess calcium build-up in these areas as it can lead to arthritis and osteoporosis.
A 2013 study published in Nutrients explains that, “Magnesium deficiency contributes to osteoporosis directly by acting on crystal formation and on bone cells and indirectly by impacting on the secretion and the activity of parathyroid hormone and by promoting low grade inflammation…. Overall, controlling and maintaining magnesium homeostasis represents a helpful intervention to maintain bone integrity.” 
In fact, build-up of calcium in soft tissues such as arteries and other blood vessels can lead to unwarranted side effects such as development of atherosclerosis (build-up of plaque in the arteries that eventually thickens and narrows the arteries, increasing the risk of blood clots, heart attack, angina pain and even stroke). Similarly, heavy accumulation of calcium in the intestines and kidneys can lead to constipation and kidneys stones.
So, lets now imagine a scenario where one is taking mega doses of vitamin D. In order to convert this vitamin D into a more usable form and to properly absorb vitamin D, you need magnesium. But what if the person has low levels of magnesium? The body will draw it from the areas where it is stored. And guess which are these sites? It is your muscles and bones. So, you body pulls out the magnesium stored in the bones, teeth and muscles, depleting your levels even some more. This is also when you begin to experience systems such as muscle pain, muscle cramps, twitching and tremors. Some people may even feel anxiety, fast heart-beat, headaches, insomnia and constipation. These are all signs that your need more magnesium in the body. In other words, you have a magnesium deficiency.
Did you notice what is going on in here? On one hand, most of your existing magnesium reserves are quickly getting used up when you are taking high doses of Vitamin D. On the other hand, you won’t be able to use vitamin D without sufficient magnesium.
A 2017 study found that elderly men with low levels of magnesium could be at an increased risk of fractures. It concluded “Low serum magnesium concentrations is independently associated with an increased risk of total and femoral fractures in middle-aged Caucasian men. Further research is needed to replicate these results in women and other populations as well as assess the potential relevance of serum magnesium in fracture prevention.” 
- You need magnesium to convert inactive vitamin D into its active form, which can be now utilized by the cells. Without healthy levels of magnesium, vitamin D would remain inactive and unutilized.
- You need magnesium to activate nearly all enzymes involved in vitamin D metabolism in liver and kidneys.
A lot of credible research suggests that the role of vitamin D goes beyond bone and muscle health. You have vitamin D receptors on almost every cell of the body and that includes cells of the immune system, heart, brain, intestines, lungs and thyroid gland. This means vitamin D plays an important role in keeping your heart, brain, thyroid and immune system healthy.
- Helps in building strong bones and reduces the risk of osteoporosis
- Reduces inflammation
- Boosts natural immunity and reduces the risk of infections like flu and other respiratory tract infections
- Reduces the risk of allergies, asthma and inflammatory skin disorders
- Reduces the risk of autoimmune disorders including thyroid disorder, rheumatoid arthritis and inflammatory bowel disease
- May reduce the risk of autism in children
- Supports heart health and reduces the risk of arterial calcification, atherosclerosis, peripheral artery disease (PAD), stroke and heart attack
- Improves energy levels
And what about magnesium?
After calcium, potassium and sodium, magnesium is the fourth most abundant mineral you have in your body. As we mentioned early in this blog, magnesium fires up many bio-chemical reactions in the body, each needed for healthy cellular and organ functions.
You need magnesium for:
- Regulating calcium levels
- RNA and DNA synthesis
- DNA repair
- Producing glutathione - the mother of all antioxidants
- Activating a large number of transporters and enzymes
- Improving the antioxidant status of the body, and reducing the oxidative damage caused by free radicals
- Making vitamin D and B6 more available to the cells
- Regulating various hormones and neurotransmitters
- Muscle cramps
- Heart failure and heart disease
- Preeclampsia and pre-term labour
- Fibromyalgia and chronic fatigue
- Premenstrual symptoms (PMS)
- Radiation exposure
- Poor sleep and poor mood
- High stress levels
- Hearing loss and tinnitus
Poor gastrointestinal health and conditions like Chron’s and Celiac disease may lead to impaired absorption of magnesium in the intestines, causing low levels or deficiency. Chronic stress, infections and antibiotics also deplete magnesium.
How to correct magnesium deficiency?
You can increase your intake of magnesium rich foods that include most nuts and seeds, broccoli, egg yolk, green leafy vegetables and whole grains. You can also take magnesium supplements.
Do you take oral magnesium in the form of powder or pills? Chances are you may experience symptoms like bloating, diarrhea and cramps in abdomen. You can prevent this by either using a magnesium oil spray or taking a liposomal magnesium supplement.
You can spray magnesium oil on to your skin. This can effectively increase your magnesium levels without the expected side effects. Another way to reverse magnesium deficiency is to take a high-quality liposomal supplement, which helps in improving the amount of mineral that reaches your cells and tissues. Liposomal supplements are very effective in improving the bio-availability and absorption of a nutrient by your cells.
And remember, your vitamin D supplements are of no use if your magnesium doesn’t lie in a healthy range. What is challenging is that you can’t diagnose a magnesium deficiency simply by getting a blood test done. That is because most of the magnesium is stored in the muscles and bones. More specifically, 40% of total magnesium in the body is present within the cells and nearly 60% of magnesium is present in bone and teeth. Less than 1% of the magnesium is found circulating in the blood stream, making it difficult to detect a deficiency with mere a blood work.
It is important that you maintain your magnesium levels, especially when you are taking vitamin D supplements. Here, it is extremely important to mention that vitamin K2 also plays an important role in this entire calcium-vitamin D-magnesium equation. Vitamin K2 is another under-appreciated nutrient. But you must know that both Vitamins K2 and D3 work together to regulate calcium levels. While you need vitamin D to absorb calcium and increase its levels in the body, vitamin K2 directs this calcium towards the bones while keeping it away from soft tissues, where it can create various health issues. In this way, you need a healthy balance of vitamin D, magnesium and vitamin K2 for healthy bones and healthy heart. Clearly, it is not the calcium that is the problem as mostly believed, but rather the imbalance in other nutrients that cause excessive calcification and associated health issues.
- Uwitonze et al. Role of Magnesium in Vitamin D Activation and Function. The Journal of the American Osteopathic Association. 2018
- American Osteopathic Association. "Low magnesium levels make vitamin D ineffective: Up to 50 percent of US population is magnesium deficient." ScienceDaily. 2018.
- Castiglioni et al. Magnesium and osteoporosis: current state of knowledge and future research directions. Nutrients. 2013.
- Kunutsor et al. Low serum magnesium levels are associated with increased risk of fractures: a long-term prospective cohort study. European Journal of Epidemiology. 2017