Published November 28 2016
All of the minerals in the body are important for optimal health, but if I were to prioritize the importance of each mineral, magnesium might be on top of the list. This mineral is a cofactor in over 300 enzymatic reactions, and while many people with both hypothyroid and hyperthyroid conditions are deficient in magnesium, many other conditions are also associated with a magnesium deficiency. In this article I’m going to talk about the importance of magnesium with regards to thyroid health, as well as other conditions that are commonly associated with a magnesium deficiency. I’ll also discuss some of the different forms of magnesium, including magnesium oxide, magnesium citrate, magnesium glycinate, and a few other forms.
As I mentioned in the opening paragraph, magnesium plays a role in hundreds of enzymatic reactions. Although this may sound impressive, I still don’t think most people realize how critically important this mineral is. Here is a list of some of the more important roles of magnesium (1) :
- Adenosine triphosphate (ATP) metabolism
- DNA and RNA synthesis
- Protein synthesis
- Muscle contraction
- Blood pressure regulation
- Insulin metabolism and blood glucose control
- Vasomotor tone
- Nerve transmission
- Neuromuscular conduction
So for example, if you have elevated insulin levels on a blood test and eat a healthy diet with minimal carbohydrates and sugars, this very well might be due to a magnesium deficiency. Or if you have high blood pressure then this also can be due to a magnesium deficiency. Sure, there can be other causes, but a magnesium deficiency shouldn’t be overlooked. If someone has muscle spasms then one of the first things they should rule out is having a magnesium deficiency. Those people with insomnia should also rule out a magnesium deficiency. But how about if you are experiencing some of these issues and are already supplementing with magnesium? Well, perhaps you don’t have a magnesium deficiency, although it also is possible that you aren’t taking enough magnesium, or the correct form of magnesium, which I’ll discuss later in this article.
How Does Magnesium Relate To Thyroid Health?
Although both people with hyperthyroid and hypothyroid conditions commonly demonstrate a magnesium deficiency in clinical practice, the research shows that those with hyperthyroidism and Graves’ Disease are more likely to be deficient in magnesium. In fact, a few studies not only show that magnesium is lower in hyperthyroidism, but that treatment with the antithyroid medication Methimazole helped to increase the magnesium levels (2)  (3) . So while having patients with hyperthyroidism supplement with magnesium might be a good idea, correcting the thyroid hormone imbalance can result in normalization of the magnesium levels. Of course this assumes that the hyperthyroidism was solely responsible for the deficiency, as many people are deficient in magnesium due to other factors, such as eating a poor diet and/or having an unhealthy gut.
But how about those with hypothyroidism and Hashimoto’s Thyroiditis? Although the research doesn’t show a direct correlation between hypothyroidism and a magnesium deficiency, this doesn’t mean that people with hypothyroid conditions aren’t commonly deficient in magnesium. Remember that many people in general are deficient in magnesium, and so while having low or depressed thyroid hormone levels might not affect the magnesium status, many people with hypothyroidism and Hashimoto’s Thyroiditis are deficient in magnesium due to other factors.
What Other Conditions Are Commonly Associated With A Magnesium Deficiency?
Depression. There is evidence that low magnesium levels can cause depression. A recent study suggested that a low magnesium intake can increase the risk of developing depression (4) . A cross-sectional study involving 8,894 adults found a significant association between very low magnesium intake and depression, especially in younger adults (5) . Another study showed that a magnesium deficiency can cause depressive-like behavior by altering the microbiota-gut-brain axis (6) .
Migraines. A magnesium deficiency may play a role in some people with migraines. Magnesium concentrations have an effect on serotonin receptors, nitric oxide synthesis and release, NMDA receptors, and a variety of other migraine related receptors and neurotransmitters (7) . One journal article suggested that a magnesium deficiency may be present in up to half of migraine patients (8) . A meta-analysis looked to evaluate the effects of intravenous magnesium on acute migraine attacks and oral magnesium supplements on migraines (9) . The study showed that intravenous magnesium reduces acute migraine attacks, while oral magnesium reduces the frequency and intensity of migraines (9) .
Cardiovascular health. Magnesium can also benefit cardiovascular health. One study looked at the association of serum magnesium concentrations with risk of heart failure, and found that lower serum magnesium levels was associated with future risk of heart failure (10) . And since serum magnesium isn’t the best method of determining if someone has a magnesium deficiency, one can argue that more accurate testing methods might result in a stronger correlation. A meta-analysis looked at the effects of magnesium on blood pressure, and the findings indicated that magnesium supplementation can lower blood pressure in adults (11) . A 24 week, randomized, double-blind study involving 52 overweight and slightly obese individuals showed that supplementation with magnesium improves arterial stiffness (12) .
Diabetes and Prediabetes. Type 2 diabetes is frequently associated with both extracellular and intracellular magnesium deficits (13) . Intracellular magnesium plays a key role in regulating insulin action, insulin-mediated-glucose-uptake and vascular tone (13) . Magnesium can also play a positive role in gestational diabetes, as a randomized, double-blind study showed that magnesium supplementation among women with gestational diabetes had beneficial effects on the metabolic status and pregnancy outcomes (14) . Another study evaluated the effectiveness of oral magnesium supplements in the reduction of plasma glucose levels in adults with prediabetes and low magnesium levels (15) . The results showed that supplementing with magnesium reduces plasma glucose levels and improves the glycemic status of adults with prediabetes (15) .
Cancer. Having sufficient magnesium levels might prevent the formation of certain types of cancers. One study I came across showed that there was a significant preventive effect of dietary magnesium for colorectal cancer (16) . Another study confirmed this, as it mentioned that magnesium intake around 400 mg/day from both dietary and supplemental sources is associated with a lower incidence of colorectal cancer in postmenopausal women (17) . Another study I came across showed that magnesium may be beneficial in terms of preventing pancreatic cancer (18) .
Signs of a Magnesium Deficiency
Some of the early signs of a magnesium deficiency include loss of appetite, lethargy, nausea, vomiting, fatigue, and weakness. If someone has a moderate to severe magnesium deficiency then this may result in tremors, muscle cramps, tetany and generalized seizures, and even cardiac arrhythmias (19) . Conditions that may directly lead to a magnesium deficiency include chronic alcohol consumption, inflammatory bowel disease, Celiac disease, hyperthyroidism, and renal disease (20) .
Food Sources of Magnesium
Although correcting a magnesium deficiency might require magnesium supplementation, you of course want to make sure you are consuming foods rich in magnesium as well. Green leafy vegetables are an excellent source of magnesium. Nuts, seeds, and legumes are also good sources, although these foods are excluded from an autoimmune paleo diet. You can also get some magnesium through the water, although this won’t be the case if you are drinking distilled or reverse osmosis water. On the other hand, a good quality spring water is a source of magnesium, along with calcium and potassium.
Different Types of Magnesium Supplements
I usually recommend magnesium citrate or magnesium glycinate/malate to my patients. Other forms include magnesium oxide, magnesium taurate, magnesium lactate, and magnesium orotate. All of these can be beneficial, although I would try to avoid magnesium oxide due to its low bioavailability. In fact, if you take a multivitamin, one way to find out quickly if it is of low quality is to see if it uses magnesium oxide as the form of magnesium. Let’s take a look at some of the more common forms of magnesium supplements:
Magnesium oxide. This is a non-chelated form of magnesium, and while magnesium oxide is commonly used in research studies, it has low bioavailability when compared to other forms of magnesium (21) .
Magnesium citrate. This consists of magnesium with citric acid, and it’s commonly recommended to help with constipation, although it can be beneficial in other conditions as well. One study I came across showed that magnesium citrate didn’t only show greater bioavailability over magnesium oxide, but also over a magnesium amino-acid chelate supplement (22) .
Magnesium glycinate. This is a chelated form of magnesium that has a high level of absorption and bioavailability.
Magnesium malate. This consists of magnesium with malic acid, which in turn supports energy production and lactic acid clearance.
Magnesium taurate. This consists of magnesium combined with taurine, and can help to provide more of a calming effect. One study shows that the combination of magnesium and taurine may improve insulin sensitivity, and may also reduce the risk for developing vascular complications associated with diabetes (23) . Another study suggested that magnesium taurate might be beneficial for the prevention of treatment of eclampsia and pre-eclampsia (24).
Magnesium orotate. Magnesium is a complex of magnesium plus orotic acid. There is some evidence that magnesium orotate might offer protection to the nervous tissue, along with the muscles of the heart (25) . Another study showed that it can benefit those with severe congestive heart failure (26) .
Magnesium lactate. There doesn’t seem to be too many studies on this form of magnesium, although one study I came across showed that magnesium lactate can benefit people with osteoporosis (27) .
Checking Magnesium Status
Assessing magnesium status is challenging, and the reason for this is because most magnesium is located inside of the cells or in the bone. Serum magnesium is commonly used for evaluating magnesium status, although this isn’t a reliable indicator for a few reasons. First of all, only 0.3% of total body magnesium is found in the serum (28) . Second, like calcium, the body will do everything it can to maintain healthy serum magnesium levels. RBC magnesium is a better indicator of magnesium status, although something called the magnesium loading test also seems to be pretty accurate. With this test, the percentage of magnesium retained after parenteral administration of magnesium is determined (28) . The problem is that most labs don’t offer the magnesium loading test, and so an RBC magnesium test is more commonly ordered.
What Causes Excessive Magnesium Levels?
Every now and then someone will have high magnesium levels. Elevated magnesium levels in the blood usually is due to excessive intake of magnesium. It can be caused by taking high doses of magnesium supplements, although something else to keep in mind is that magnesium containing medications are commonly used as laxatives, antacids, and rectal enemas (29) . Other potential causes of elevated magnesium levels in the blood include renal failure, lithium therapy, and Addison’s disease (29) . Elevated magnesium levels on a hair mineral analysis are common, and usually indicates that magnesium is biounavailable.
In summary, magnesium is a cofactor in over 300 enzymatic reactions, and has many important roles. The research shows that those with hyperthyroidism and Graves’ Disease are more likely to be deficient in magnesium, although many people with hypothyroid conditions are deficient as well. Some other conditions which are commonly associated with a magnesium deficiency include depression, migraines, cardiovascular conditions, diabetes, and cancer. Some of the different forms of magnesium supplements include magnesium citrate, magnesium glycinate, magnesium malate, magnesium taurate, magnesium orotate, magnesium lactate, and magnesium oxide.