Magnesium is the fourth most abundant mineral in your body after potassium, calcium and sodium.
It’s one of the more common nutrient deficiencies in North American.
According to the Canadian Community Health Survey (CCHS), between 39 to 70% of men between the ages of 19 to 71 years and older, aren’t getting the recommended minimum daily amount (420 mg/day) of magnesium.
It’s not much better for women either. The CCHS also shows that about 41 to 55% of women, also between 19 and 71, are missing the mark (320 mg/day) when it comes to their magnesium intake as well.
Health concerns of low magnesium intake
Magnesium is involved in many different pathways that overlap, so there’s often several possible signs and symptoms of a chronic, sub-optimal magnesium intake.
It’s estimated that magnesium aids in over 300 different enzyme systems that regulate diverse biochemical reactions in your body, including protein synthesis, muscle and nerve function, blood glucose control, insulin production and function, and blood pressure regulation (1, 2, 3).
Magnesium is also involved in energy production. It helps your body use the energy it gets from the digestion of food to make the master energy molecule ATP (adenosine triphosphate). It’s also involved in bone development, and is needed for the synthesis of arguably THE most important information molecule(s) DNA and RNA (2, 3).
It also supports the electrical activity of your nervous system. By doing so, it’s involved in nerve impulse control; the cross-talk between your neurons, and is crucial for a healthy and strong heart beat and muscle contractions (4).
With that in mind, it’s no surprise how not getting enough magnesium can take its toll on your body and health. Common health problems associate with a chronic low magnesium intake are (1, 2, 3):
- Insulin resistance and diabetes
- Migraines
- Heightened impact of stress
- Osteopenia and osteoporosis
- Fibromyalgia
- High blood pressure
- Anxiety and depression
- Fatigue and muscle weakness
- Irregular heart beat
- Heart disease
- Increased stroke risk
- Muscle twitches and cramps
Nutrient interactions
We need about 25 vitamins and minerals per day to be healthy. That’s pretty amazing when you stop to think about it. Only 25 micronutrients are needed to support the metabolic activity of the some 33 TRILLION cells that make up your body.
Nutrients interact and support each other and there are a handful that stand out where magnesium is concerned including other nutrients that are neither a vitamin nor a mineral.
Vitamin D3 and calcium
The active form of vitamin D, calcitriol, may enhance the absorption of magnesium but it’s not clearly understood as calcitriol’s role in the absorption of calcium and phosphorus (5).
While maintaining optimal blood concentrations of both the inactive (calcidiol) and active (calcitriol) forms of vitamin D3 is crucial for health, a low blood concentration of calcitriol doesn’t seem to pose the same concern for magnesium absorption.
But, magnesium IS needed to activate the conversion of calcidiol into the active form calcitriol. You can increase your calcitriol simply by increasing your magnesium intake.
High calcium intake from food and supplements does not affect magnesium balance (what you consume versus what you excrete) in the vast majority of studies (6, 7).
But it’s generally accepted that most of us get too much calcium at the expense of magnesium though. Some experts suggest a ratio of 2:1 calcium to magnesium and others thing a 1:1 ratio is ideal.
Because we’ve be hit over the head for decades that there’s a calcium emergency, many are consuming lots of dairy and taking calcium supplements while missing the mark for magnesium. It’s not uncommon for people to only be getting about 225 mg of magnesium and 1000-1200 mg or more of calcium per day.
Fiber
Large intakes of fiber have been shown to reduce and decrease magnesium absorption and utilization (6, 7). This is because fiber, derived from plants, contain anti-nutrients which may interfere with mineral absorption.
The extent to which fiber can impede absorption isn’t clear cut. For those eating a variety of foods, both plant and animal, using a variety of preparation methods, zinc status isn’t usually a problem outside those in established zinc deficiency risk categories.
Protein
Sources of protein and protein quality influence magnesium absorptioin. Animal sources of nutrients are absorbed more efficiently versus those from plants (plants have lots of anti-nutrients such as phytates which inhibit absorption to a degree).
By eating a variety of foods, you’ll be in the best position to absorb nutrients including magnesium. One study found that magnesium absorption was related to protein intake. Magnesium absorption is lowest when total daily protein is low, e.g. 30 g or less per day (8).
A low protein intake isn’t typically a problem for most but can be in people who are at risk for poor protein intake including those with restrictive eating habits, or poor appetites. In these cases, supportive magnesium supplementation would be less effective.
Zinc
Zinc can interfere with magnesium absorption but this only applies to zinc from supplements, not food. Even then, it takes a lot of supplemental zinc for it to be a problem.
One study found that 142 mg/day of zinc supplements in healthy adult men interfered with magnesium absorption and threw off magnesium balance (the balance between how much magnesium is consumed versus what’s normally excreted (9).
Eating zinc-rich foods or taking supplements that contain less than 40 mg/day total will not be a problem.
Dealing with anti-nutrients
As stated, plants have compounds that can interfere with the absorption of their nutrients, especially minerals (10).
They are not a major concern for most people, but may become a problem during periods of malnutrition, or among people who base their diets almost solely on grains and legumes.
This isn’t to alarm you, the health benefits of eating certain foods with anti-nutrients outweigh any potential negative nutritional impact.
Anti-nutrients can be neutralized with a little effort. This is typically achieved without you even thinking about it. Preparation methods that help to reduce the impact of anti-nutrients include:
- Soaking (11, 12)
- Sprouting (13, 14)
- Fermentation (15, 16)
- Boiling (17, 18)
- Eating those foods with other foods at the same time that enhance nutrient absorption (code for “mixed meals”).
On a personal note, I routinely soak nuts and seeds to make them more digestible. I’ll use them chopped in salad or throw them into a smoothie; they blend very well once soaked.
Food sources of magnesium
No doubt, one reason so many of us are magnesium deficient is because we aren’t eating enough foods high in magnesium. Keeping in mind magnesium’s all-important role in health and wellness, I urge you to consider adding these magnesium-rich foods to your daily menu:
Pumpkin seeds
One of the best sources of magnesium are pumpkin seeds; they have whopping 185 mg per 1/4 cup. These are staple in my pantry. I add them to salads, eat them as a snack, at them to my smoothies or on top of Greek yogurt with berries.
Spinach
With a decent 157 mg per 1 cup cooked, cooked spinach is a stand out source of magnesium. Boiling the spinach will help to make the magnesium more absorbable over raw spinach. This isn’t to say raw spinach doesn’t have any value, it does. This is why it’s best to get a variety of cooked and raw foods. On a side note, spinach, like all leafy greens, are especially good for your gut bacteria.
Quinoa
Still popular. This so-called pseudo-grain is another good source of magnesium with a whopping 118 mg per 1 cup cooked. You can use quinoa as a side dish, add some cold cooked quinoa to a smoothie or cook it up like as a quinoa porridge.
Sunflower seeds
Like pumpkin seeds, sunflower seeds are another standout source with 1/4 cup has 113 mg. Include them anywhere you would other seeds; they’re also a staple of mine and get added to salads or tossed with cooked vegetables.
Almonds
Another decent source of magnesium, a 1 oz (23 almonds) serving has 80 mg. Whether it’s whole almonds or almond butter, these nuts are an easy and tasty way to sneak in more magnesium. These have a nice soft texture (at least I like it) but soaked overnight in the fridge. Soaking makes them easy to chopped to add to salads and allows them to be blended smoothly into shakes.
Avocado
This creamy delight has 58 mg per medium sized fruit. While this doesn’t sound like a lot, it’s about 13% of the recommended amount for men and 17% for women. As part of your daily tally, it all adds up. Beyond the usual avocado toast, or guacamole, or tossed in a salad, one of my favourite ways to use avocados in my daily smoothie/protein shake. It adds a smoothness and creaminess like no other.
Cacao powder
A staple for my peanut butter chocolate protein shake. Cacao powder, with 50 mg of magnesium per 2 Tbsp (30 ml) is one of the more delicious ways to snack in more magnesium. Try making your own hot chocolate with milk or mild alternative like organic soy beverage (made with whole soy beans versus with made with water and isolate soy protein), almond, or even coconut milk. For a unique hot chocolate, try this Maca Hot Chocolate version made with the adaptogen maca.
Bottom line
Magnesium deficiency is very common with potential consequences to health.
Some studies suggest between 50 to 75% of those in Western societies do not meet their dietary requirements for magnesium.
The symptoms of a functional magnesium deficiency are usually subtle unless your levels become severely low where an overt/clinical deficiency may occur. A functional deficiency may cause fatigue, muscle cramps, mental problems, irregular heartbeat and osteoporosis.
If you believe you may have a magnesium deficiency, you can have a test. But, blood tests are the least reliable even though they are the most popular. Testing the amount of magnesium in your red blood cells would be better, otherwise a nutrition professional can assess your intake, risk for deficiency and check for any symptoms.
For more on the different types of test, see my other post here.
To ensure you’re getting enough magnesium, be sure to eat plenty of magnesium-rich whole foods every day using a variety of preparation methods. You’ll likely benefit from magnesium supplements as well. Again a nutrition professional can determine the right dose for you.
Doug Cook RDN is a Toronto based integrative and functional nutritionist and dietitian with a focus on digestive, gut, mental health. Follow me on Facebook, Instagram and Twitter.