Call to Learn About our 10% Discount
(615) 721-8008‬

What are Magnesium Supplements Good For? Taking the Mystery out of Magnesium.

Holistic Health

As of late, magnesium is the supplement that I’m asked the most about. But, because there are so many forms of magnesium it can be quite a mysterious nutrient. How do you know what form of magnesium to take and for what conditions? 

I promised you answers and in this article, I’m going to answer your burning questions. 

I’ll unlock the mystery of magnesium and you’ll learn:

What Is Magnesium Good For? What Does Magnesium Do? 

Let’s start with some facts. Magnesium is an essential mineral in the body with a role in the physiological function of the brain, heart, and skeletal muscle. It goes beyond that; magnesium plays over 800 different essential biochemical roles in the body! 

As the fourth most abundant cation (charged mineral) in the body, magnesium acts as a cofactor for more than 300 enzymatic processes responsible for regulating diverse biochemical reactions including, energy metabolism, protein synthesis, muscle and nerve function, blood glucose, and blood pressure control. Magnesium is a major player! 

While we obviously need magnesium to maintain homeostasis, or balance, throughout the body, deficiencies are very common. Dr. Martha Shrubsole PhD, a research professor in the Department of Medicine at Vanderbilt University, who has led a research portfolio investigating the role that magnesium may play with cancer as part of the Personalized Prevention of Colorectal Cancer Trial was quoted saying; 

“Magnesium deficiency is an under-recognized issue with up to 80 percent of people not consuming enough magnesium in a day to meet the minimum recommended dietary allowance (RDA).” 

When you think about this, it’s not surprising that 50% of the US population is deficient in magnesium!

Magnesium deficiencies have big implications in our health. Neurologist Dr. Norman Shealy stated, “Every known illness is associated with a magnesium deficiency.” He pointed out that magnesium is not only required for the electrical stability of every cell in the body, it’s the most critical mineral in this process. Dr. Shealy believed that magnesium deficiency was potentially responsible for more diseases than any other nutrient. There is no doubt magnesium plays an important role. 

On a side note, without sufficient levels of magnesium we cannot metabolize Vitamin D. So, while Vitamin D deficiencies are far more recognized, all the supplementation in the world will not be sufficient if low magnesium levels are causing Vitamin D to be stored and inactive. And to further complicate things, Vitamin D supplements can increase calcium and phosphate levels (while they remain Vitamin D deficient) which can in turn lead to vascular calcification due to magnesium levels not being high enough to metabolize the Vitamin D. I tell people all the time… “It’s never one thing.”

How Much Magnesium Do You Need?

The RDA for magnesium is based upon age, life stage and sex. This chart is from The Linus Pauling Institute at Oregon State University

Table 1. Recommended Dietary Allowance (RDA) for Magnesium

Life Stage


Males (mg/day)

Females (mg/day)
Infants 0-6 months 30 (Al*) 30 (AI)
Infants 7-12 months 75 (AI) 75 (AI)
Children 1-3 years 80 80
Children 4-8 years 130 130
Children 9-13 years 240 240
Adolescents 14-18 years 410 360
Adults 19-30 years 400 310
Adults 31 years and older 420 320
Pregnancy 18 years and younger - 400
Pregnancy 19-30 years - 350
Pregnancy 31 years and older - 360
Breast-feeding 18 years and younger - 360
Breast-feeding 19-30 years - 310
Breast-feeding 31 years and older - 320

*Adequate Intake

In theory, we should be able to get these levels on a daily basis by eating a variety of whole foods. Good sources of magnesium include leafy green vegetables, legumes, nuts and seeds. However, even with these plant foods in abundance in the diet, we may not be getting enough. The reason has to do with the soil. The magnesium we get from food is first in the soil where the food is grown. As industrial agriculture expanded, soil fertility has decreased and as a result magnesium-rich foods do not contain as much magnesium as they once did. 

For this reason, I find that most people benefit from additional supplementation, given the widespread needs for magnesium throughout the body. 

But, before supplementing, let’s talk about testing. 

Why Guess When You Can Test – Magnesium Testing

I always recommend that before you begin supplementing with anything you get micronutrient levels tested so that you aren’t giving yourself more of something than you need… we don’t want to create a problem where there is none. Testing for magnesium deficiency has traditionally been performed using serum levels, however, since only 1% of magnesium in the body is detected the blood, this is not the most accurate or reliable method of testing. In order to understand this, you need to understand magnesium regulation and storage in the body. 

Interestingly, even though we absorb about 30% of our magnesium from ingesting food or supplements, the main site of regulation is the kidneys. 95% of the magnesium secreted is reabsorbed, meaning it is recycled and used again in the body. Any excess magnesium in the blood is sent to be excreted via the kidneys. 

Magnesium is primarily stored in the bone, muscle and soft tissue. Since the body self-regulates magnesium levels by pulling it from the bones or other tissue when blood levels are low, looking at blood levels alone are likely to look normal when problems may exist. And since it is hard to test the bone or tissues for magnesium levels, we need another method. 

This is why testing methods are so important to get an accurate picture of not only magnesium, but any nutrient of interest. Therefore, we test the levels of magnesium found in the erythrocytes, or red blood cells (RBC). While references ranges vary from lab to lab what is typically considered to be the normal for magnesium in the RBC range from 4.0 to 6.8mg/dL. 

It’s important to keep in mind that these are simply reference ranges and part of the whole picture about magnesium. You’ll need to work with your functional medicine provider to determine what is necessary for you because we are all unique individuals. 

However, if you determine you are low in magnesium based on a full clinical picture of lab testing, symptoms, diagnoses and other factors, supplementation is a wonderful solution for improving magnesium status. 

Magnesium Supplements

What’s up with all the different forms of magnesium and what is the best kind to take? 

Very simply the best kind to take is the one that will be best utilized by your body! And that is going to be determined by the form, quality, absorbability, solubility and bioavailability. What does all that mean? Let’s break it down.

For a substance to be absorbed or diffused through a membrane it has to first be dissolved into a medium where it is permeable in order to be bioavailable… in other words it has to get into the body in a form that is readily accepted to be used by the body. Keep in mind that minerals are helped or hurt by what’s in your stomach and intestines when you consume them. For instance, fat increases absorption while fiber decreases absorption of minerals. So, take them with a little fat and your Vitamin D! 

Here are some of the most common forms of magnesium supplements:

The benefits of magnesium are many: this is a nutrient to consider and optimize as needed. Since magnesium deficiency is epidemic, I recommend testing for most people. Please work with your functional medicine provider to determine the best way to optimize your levels and what form of magnesium to use in order to do so. Interested in micronutrient testing? Please make an appointment to get started.

You Can Check Out Our Favorite Magnesium Supplements Here:

I like this Reacted Magnesium by Ortho Molecular which is a combination of malate, citrate, and glycinate because often we need various levels of approach.

And this is my favorite… magnesium citrate as Natural Calm (Raspberry Lemon flavor) is my go to form many times.

If you are looking for pure glycinate this is my choice – Pure Encapsulations Magnesium glycinate

My choice for magnesium threonate is Metagenics Mag L Threonate

When using magnesium malate, I prefer Designs for Health’s Magnesium Malate

One magnesium product line that I have not personally used but am excited about trying is the Ancient Minerals line. They came highly recommended to me. 

Ancient Minerals has magnesium oil, flakes, gel, and lotion. 

And if you try them or have used them let me know your thoughts! I’m super excited to get them in and try them myself! Let us know if you are interested and we can ship them to you. 


Alawi, A. M. A., Majoni, S. W., & Falhammar, H. (2018). Magnesium and Human Health: Perspectives and Research Directions. International Journal of Endocrinology, 2018, 1–17. doi: 10.1155/2018/9041694

Blancquaert, L., Vervaet, C., & Derave, W. (2019). Predicting and Testing Bioavailability of Magnesium Supplements. Nutrients, 11(7), 1663. doi: 10.3390/nu11071663

Does magnesium hold the key to vitamin D benefits? (n.d.). Retrieved from

Ghabriel, M. N., & Vink, R. (n.d.). Magnesium transport across the blood-brain barriers. Magnesium in the Central Nervous System, 59–74. doi: 10.1017/upo9780987073051.004

Gröber, U., Werner, T., Vormann, J., & Kisters, K. (2017). Myth or Reality—Transdermal Magnesium? Nutrients, 9(8), 813. doi: 10.3390/nu9080813

Kass, L., Rosanoff, A., Tanner, A., Sullivan, K., Mcauley, W., & Plesset, M. (2017). Effect of transdermal magnesium cream on serum and urinary magnesium levels in humans: A pilot study. Plos One, 12(4). doi: 10.1371/journal.pone.0174817

Low magnesium levels make vitamin D ineffective. (2018, February 26). Retrieved from

Magnesium Citrate vs. Magnesium Glycinate. (2020, January 20). Retrieved from

Perlmutter, D. (2015, February). Retrieved from

Rosanoff, A., Weaver, C. M., & Rude, R. K. (2012). Suboptimal magnesium status in the United States: are the health consequences underestimated? Nutrition Reviews, 70(3), 153–164. doi: 10.1111/j.1753-4887.2011.00465.x

Watts, D. L. (1988). The Nutritional relationships of magnesium. Journal of Orthomolecular Medicine, 3(4), 197–201. Retrieved from


The Fork Functional Medicine
110 3rd Ave N.
Franklin, TN 37069

Phone: (615) 721-8008
Fax: (615) 237-8331‬

Hours of operation

Monday: 9am - 5pm
Tuesday: 9am - 5pm
Wednesday: 9am - 5pm
Thursday: 9am - 5pm
Friday: 9am-5pm
Saturday-Sunday: CLOSED

By appointment only

Telemedicine visits are available to patients in the State of Tennessee. See further information under patient info.