How To Tell If You Need Magnesium

by in Blog August 8, 2020

You might hear and read a lot about magnesium, because it’s such an important nutrient! It participates in over 300 reactions within the body, helping to power your body and metabolism. Yet it’s harder than ever to get sufficient amounts. The food we eat has lower levels than it used to (due to soil, farming practices, and processing), and our medications and lifestyles deplete our body’s stores. So how do you know if you need magnesium, and if you should consider supplementing it?

Prevalence of Deficiency

Studies show that many, if not most, of us have insufficient stores of magnesium. 90% is in bone and muscle, and only 1% of it is in the blood. This means the body’s stores can become low before it’s detected in the blood. Therefore, prevalence of deficiency is underestimated. Even so, here’s what studies have found (1):

  • 48% of the general US population under consumes for their body’s requirements
  • 84% of postmenopausal women with osteoporosis are deficient
  • 30% of youth have insufficient magnesium intake 
  • 42% of teenagers have low magnesium based on retention during a loading test
  • Around 20% of the general population has low levels in blood

How do you know if you should be counted in the portion that’s deficient? Read below for some common associations between deficiency and conditions.

You Need Magnesium for Muscle Health

Magnesium is an electrolyte. As such, it helps with muscle relaxation, and is released in sweat. Our arteries and heart are also made up of muscle cells. Hence, when magnesium is low, the vessels become strict and lead to high blood pressure. In addition, the heart struggles to function regularly, and risk of arrhythmia and cardiovascular disease increases. (1)

Of course, this means that you can get muscle cramps when magnesium is low, as well as restless legs syndrome. Increasing magnesium can lead to muscle relaxation. This release of tension can decrease the effects of anxiety, stress, and insomnia.

You Need Magnesium for Blood Sugar Control

Insufficient magnesium can lead to insulin resistance. This means you’ll be more likely to have hypoglycemia (low blood sugar) after eating carbohydrates. Eventually, it may develop into chronically elevated blood sugar or prediabetes, and then diabetes. Research shows that for each 50mg increase in magnesium, there was a 3% decrease in fasting glucose. (2)

A study of those with low magnesium status and prediabetes revealed that supplementation of 380mg per day reversed the prediabetes in 51% of those taking it, vs 7% taking placebo. (3)

The difference becomes most significant when taken for 4 months or longer. (4) Supplementation can even reduce inflammatory markers in the blood in this patient population. (5)

Other Uses For Magnesium

  • Allows for normal bowel function, improving constipation
  • Improves bone health and keeps calcium in the bones (6)
  • Protects against hearing loss and tinnitus (7, 8, 9)
  • Participates in the production of neurotransmitters to decrease depression and anxiety and improve sleep (10, 11, 12, 13, 14).
  • Alleviates symptoms associated with women’s menstrual cycles (15)
  • Reduces headaches, migraines, and incidence of asthma (15)

So How Can You Tell You May Need It?

1. Symptoms: you may need magnesium if you’re experiencing muscle cramps, anxiety, depression, trouble sleeping, fatigue, constipation, PMS, headaches or migraines, or abnormal bone density.

2. Lifestyle factors: you may be at higher risk for deficiency and need magnesium if you have high stress, use steroid medications (oral, inhaler, injections), take a PPI or other antacid, use several medications, sweat often, drink several cups of coffee, regularly consume alcohol, or have GI issues.

3. Test Your Blood; the most common test is serum magnesium. If the test shows your level is low, then you definitely have a deficiency. However, if it’s normal, you may still need it. Remember, only 1% is in the blood, and the serum draws from the red blood cells (RBC). Therefore, a RBC magnesium is more accurate, but still does not give the complete picture. If it’s normal, but you’re having the symptoms above, then it’s best to self-test. Start supplementing, and see if any symptoms improve.

How To Meet Your Magnesium Needs

A healthy person without the risk factors listed above needs 300-400mg of magnesium per day. See below for how to get this.

  • Food: As mentioned earlier, it is getting more difficult to meet magnesium needs because of greater usage by the body and lower amounts in food. However, in general, these foods will be decent sources: nuts, seeds, beans, leafy greens, and whole grains. Specifically, seeds have the highest amount, in this order: hemp, pumpkin, sesame, and sunflower. Moderate amounts (50-100mg) can be found in chocolate, avocado, black beans, and chickpeas.
  • Supplements: One thing is for sure: do not use magnesium oxide, the form typically found in grocery stores, if you’re trying to get more magnesium in your body. Studies have found no meaningful increase when supplementing with it compared to placebo. (16) Much better absorption can be achieved with magnesium citrate, while still leaving some unabsorbed magnesium leftover in the intestines to loosen the stool. If you’re going for best absorption (and therefore minimal stool-loosening), then choose magnesium malate or glycinate. I’m partial to malate because it’s used for energy production, and we can get sufficient glycine from bone broth or collagen powder, which I recommend to my patients. Finally, magnesium threonate uniquely has the ability to carry magnesium into the brain. This can be great for migraines, anxiety, insomnia, and memory loss. To get the ones we use in our practice, go here.

Summary: If your symptoms, lifestyle, or tests suggest insufficient magnesium, then increase your intake and watch your health improve!

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  1. Subclinical magnesium deficiency: a principal driver of cardiovascular disease and a public health crisis. 2018.
  2. Effect of Magnesium Supplementation on Insulin Resistance in Humans: A Systematic Review. 2017.
  3. Oral magnesium supplementation improves glycaemic status in subjects with prediabetes and hypomagnesaemia. 2015.
  4. A Systematic Review and Meta-Analysis on the Effects of Magnesium Supplementation on Insulin Sensitivity and Glucose Control. 2016.
  5. Oral Magnesium Supplementation Decreases C-reactive Protein Levels in Subjects With Prediabetes and Hypomagnesemia. 2014.
  6. Magnesium and Osteoporosis: Current State of Knowledge and Future Research Directions. 2013.
  7. Phase Two Study Examining Magnesium Dependent Tinnitus. 2012.
  8. Oral magnesium intake reduces permanent hearing loss induced by noise exposure. 1994.
  9. Relationship between serum magnesium level and subjective tinnitus. 2016.
  10. Association Between Magnesium Intake and Depression and Anxiety: The Hordaland Health Study. 2009.
  11. The association between dietary intake of magnesium and psychiatric disorders among Iranian adults. 2018.
  12. Rapid recovery from major depression using magnesium treatment. 2006.
  13. Effect of Magnesium Supplementation on Mental Health in Elderly Subjects with Insomnia. 2013.
  14. The effect of magnesium supplementation on primary insomnia in elderly. 2012.
  15. Therapeutic Uses of Magnesium. 2009.
  16. Intestinal Absorption and Factors Influencing Bioavailability of Magnesium-An Update. 2017.

  1. What specific oral magnesium do you suggest?

    • Good question, not easy to answer! It depends on the needs of the person consuming. Mag malate is great for energy production and muscle health, mag glycinate for sleep, and mag citrate or oxide for constipation. Often I use a combination. I’ve got my favorites in the Nutrients section of the catalog in Fullscript here.

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