Magnesium is the 4th most abundant mineral in the body. It is required for over 300 enzymatic reactions in the body and can support deep sleep, muscle relaxation, and proper elimination. Unfortunately, most of us are deficient in this important mineral!
Why We Are Deficient
It’s estimated that 75-80% of Americans are deficient in magnesium. There are several reasons why deficiencies are so common:
Magnesium depletion in the soil — the food grown today does not contain the same levels of magnesium as it did 50 years ago due to monoculture farming.
Poor digestion — if you aren’t properly digesting the food you eat, you aren’t absorbing the nutrients in the food. Poor digestion can also impacts your ability to absorb magnesium supplements.
A diet high in processed food — A diet high in processed foods predisposes you to magnesium deficiency.
Over consuming grains + nuts — grains and nuts contain compounds like phytate that bind to certain nutrients, including magnesium. If your diet focuses heavily on grains, your ability to get magnesium through food could be limited. Soaking and sprouting nuts and seeds degrades the phytate, increasing mineral absorption AND making them easier to digest.
Excess alcohol/caffeine consumption — alcohol and caffeine act as diuretics, causing the body to excrete magnesium and other electrolytes through the kidneys
Certain medications — antacids (shutting down digestion), anti-inflammatory meds, antibiotics, birth control, cardiovascular meds, and diuretics all deplete magnesium in the body. Click here for a more extensive list.
High stress — the body uses magnesium in several ways to counteract high cortisol and adrenaline (hormones involved in the stress response). If you are already low in magnesium, you may have an even harder time reacting to stress.
Consuming too much calcium, phosphorus, and/or vitamin D (often supplemental forms) in relation to magnesium. All three of these work synergistically in the body, so low/high levels of one will affect the others. They need to be in balance with one another.
Calcium - high calcium intake increases the need for magnesium. While calcium is stored or recycled in the body, magnesium is either used or excreted. Consuming too much calcium and not enough magnesium can lead to deficiency as well as toxic levels of calcium in the body.
Phosphorus - phosphorus intake increases magnesium need. Phosphoric acid, which is found in soft drinks, binds to magnesium in the gut making it very difficult to absorb dietary magnesium. Phosphorus also works inversely with calcium — when calcium levels rise in the blood, phosphate (an ion that contains phosphorus) levels fall.
Vitamin D - Vitamin D requires magnesium for its conversion into its active form. Over supplementing without ensuring adequate magnesium can lead to deficiency.
Testing For Magnesium Deficiency
Most magnesium in the body is stored in the bones, cells, and tissues. An estimated 1% of magnesium is found in the blood.
A common test for magnesium deficiency is serum (blood) testing. Subclinical magnesium deficiency is hard to diagnose with this test because the blood doesn’t give you a full picture of your current magnesium levels. Subclinical means that you aren’t showing any measurable symptoms of a present deficiency, but deficiency can predispose you to chronic negative health outcomes.
The abstract from this article highlights the issues surrounding testing for magnesium deficiency and why magnesium deficiencies are so common:
“Because serum magnesium does not reflect intracellular magnesium, the latter making up more than 99% of total body magnesium, most cases of magnesium deficiency are undiagnosed. Furthermore, because of chronic diseases, medications, decreases in food crop magnesium contents, and the availability of refined and processed foods, the vast majority of people in modern societies are at risk for magnesium deficiency. Certain individuals will need to supplement with magnesium in order to prevent suboptimal magnesium deficiency, especially if trying to obtain an optimal magnesium status to prevent chronic disease.”
The RBC magnesium test is the best way to test for potential magnesium deficiency. This test looks at how much magnesium is in your red blood cells instead of just looking at blood levels.
Hair Tissue Mineral Analysis (HTMA) is a tool you can use to assess the mineral content of tissues by testing hair samples. It also provides insight to other deficiencies, heavy metals, energy production and metabolism.
Signs of Magnesium Deficiency
Magnesium deficiency can show up as mild symptoms or more severe symptoms if chronically deficient.
Severe symptoms can include:
Mild symptoms can include:
Mood imbalances
Poor memory
Migraines
PMS
Insomnia
Heart irregularities
Hyperglycemia/hypoglycemia
Insulin resistance
Anxiety
Depression
Lack of appetite
Irritability
Excessive craving for sweets
Fatigue
Muscle cramps/spasms
Twitching of the face
Constipation
Dizziness
Headaches
The Importance of Magnesium
Think of magnesium as the relaxation mineral. It is supportive for people with anxiety, high stress, muscle tension, and poor sleep. Magnesium is an important cofactor needed to start over 300 biochemical processes in the body. Unlike calcium, magnesium is either used by the body or excreted through the kidneys, so it is so important that we get enough magnesium in our diet on a daily basis.
Here are a few of the important processes that require magnesium:
Energy production
Helps muscles contract and relax
Bone and teeth formation
Facilitates cell growth and repair
RNA and DNA synthesis
Promotes proper elimination
Production of sex hormones
Regulating insulin and glucose
Protein synthesis
Regulating sleep
Vitamin D metabolism
Getting Enough Magnesium Each Day
The Recommended Dietary Allowance (RDA) of magnesium for adults is 310-320 mg for females and 400-410 for males. Pregnant or lactating women require slightly different amounts. Use the chart below to see where you fall.
Chart from the National Institute of Health website.
Food Sources of Magnesium
Just because magnesium levels are lower than they used to be doesn’t mean we should avoid consuming magnesium rich foods! Here is a list of food sources of magnesium.
Spinach (cooked)
Collard greens
Potato
Almonds
Cashews
Pumpkin seeds
Black beans
Brown rice
Dark chocolate (70% or higher)
Avocados
Halibut
Salmon
Mackerel
Nutritive herbs like oat straw and nettle contain high amounts of easily absorbed magnesium and other vitamins and minerals. You can make an infusion of oat straw to drink or a tea of dried nettle leaves. Use this guide to learn how to make an oat straw infusion which is different than making a tea.
Magnesium Supplementation
Chronic digestive issues make it harder for you to get your daily intake of magnesium because if you aren’t digesting well, you aren’t absorbing nutrients. HCl levels (your stomach acid) are much lower in older adults since levels naturally decline as you age. High stress, caffeine intake, and common medications can deplete your magnesium levels, so dietary sources may not be enough to meet your daily need.
Magnesium comes in a wide variety of supplemental forms. You can take magnesium orally by tablets, powders, or liquid drops, or through the skin (transdermal). The type of magnesium will also dictate how it is absorbed and how it works in the body. For example, some types of magnesium (oxide and citrate) affect the bowels while others do not. Choose the form of magnesium that best suits your needs. As always, contact your doctor before starting any supplementation, especially if you have kidney disease, are pregnant, or breastfeeding.
Here are the most common types of magnesium and how they work in the body.
Magnesium Citrate — This form is calming and can provide muscle relaxation and reduce cramping. This form has a laxative effect as it pulls water into the colon, softening your stool. It is much more gentle than magnesium oxide, so I would start with this form for acute constipation. You’ve probably seen Natural Vitality Calm powder in your local grocery store. If you use this brand, I recommend the Original flavor. The flavored ones contain stevia, a sweetener that can cause GI discomfort.
Magnesium Oxide — this form is not easily absorbed (around 4%), so if you have low magnesium levels you will want to skip this one. This form is often used for constipation as it has a laxative effect. This form is stronger than magnesium citrate so it can cause diarrhea if too much is taken.
Magnesium Chloride — this form is used in sprays for absorption through the skin. Since this form bypasses the GI tract, it is optimal for people with chronic digestive issues and older adults who may have lower stomach acid levels. I recommend Ancient Minerals or Life-Flo magnesium spray. Some people feel a tingling sensation when first using, this can go away once magnesium levels have gone up.
Magnesium Sulfate — this is another form of magnesium absorbed through the skin. Commonly known as epsom salt, can be used in baths or foot baths. Absorption rate is pretty low for this form, but it can be helpful for muscle relaxation. I recommend Ancient Minerals or Dr. Teal’s fragrance free for epsom salt baths.
Magnesium Glycinate — this form is highly absorbable and does not cause digestive upset. It is a very calming form of magnesium and is helpful for anxiety and stress. It also supports good sleep and muscle recovery.
Magnesium Gluconate - this form is often used for people who are taking medications that interact with magnesium to correct deficiencies. In large doses it can also cause a laxative effect.
Magnesium Threonate — this form is great for enhancing learning and memory. It can be taken in the morning to improve cognitive function. This is the only form that has been shown to cross the blood brain barrier, causing an increase in brain magnesium levels.
Magnesium Malate — this form is good for energy production. It is also gentle on the stomach and helps soothe muscles.
You can supplement with single forms or find brands that combine a few different forms of magnesium into one tablet or powder. My favorite blends are Empirica and Biotics Research — avoid buying this supplement from Amazon, Biotics does not officially sell its products there.
How Much Should I Take?
The magnesium you get from food sources is easily balanced by the kidneys but you want to be careful of overusing supplemental forms. Too much supplemental magnesium can lead to nausea, diarrhea, and even toxicity Follow the recommendations listed on the bottle to know how much to take. I would not recommend exceeding 400 mg of supplemental magnesium per day. Talk with your doctor to figure out what amount is best for you.
Mineral Relationships
The mineral wheel below shows which minerals work synergistically together. If a mineral has an arrow pointing to another mineral, it means that a deficiency of that mineral or interference with its metabolism may be caused by an excess of the mineral from where the arrow originates.
I think its very important to understand that you can’t just take one mineral in isolation because it will affect levels of other minerals it is connected to.
Final Words
While supplemental magnesium can be super helpful for most people, I wouldn’t recommend taking magnesium in isolation long term. Taking one mineral in excess can lower levels of other minerals.
Magnesium, potassium, calcium, sodium, and chloride are all electrolytes that are needed for proper water absorption, cell function, and more. Taking a multi-mineral supplement may be more beneficial once a magnesium deficiency is corrected. I use Biotics Multi-Mins Fe/Cu Free. Again, the best thing to do is talk with your doctor and have them order tests to check your vitamin and mineral status.
I also would caution against focusing on magnesium oxide or citrate as a long-term solution to chronic constipation. While a laxative form can loosen stools and help produce a bowel movement, it is truly a band aid. You need to get to the root cause of why you are constipated in the first place.
Common causes of constipation are low fiber intake, poor hydration, and poor HCl (stomach acid) secretion. Dairy is a constipating food so try taking it out of your diet for 2-3 weeks to see how your body reacts. Increasing levels of progesterone during ovulation can also cause constipation. Try increasing your fiber intake a few weeks before your period. You can also use magnesium to help soften stools in acute situations.