- How much magnesium should we be getting daily?
- Recommended Dietary Allowances for Magnesium
- Popular food sources of magnesium
- Benefits of magnesium supplements
- Are there any side effects of taking magnesium?
- Who should consider magnesium supplements?
- My magnesium take-away
Since calcium plays an important role in skeletal and smooth muscle contraction, a state of magnesium depletion may result in muscle cramps, hypertension, and coronary and cerebral vasospasms. Magnesium depletion is found in a number of diseases of cardiovascular and neuromuscular function, in malabsorption syndromes, in diabetes mellitus, in renal wasting syndromes, and in alcoholism.Yikes.
How much magnesium should we be getting daily?An adult body contains about 25 grams of magnesium at any given time, 60% of which is in the bones, and nearly all the rest in soft tissue. 3 Less than 1% of magnesium is found in the blood, which makes it difficult to test for a magnesium deficiency; however, dietary surveys have shown that most people don’t get enough of this essential mineral through their food alone. 4 Dietary Reference Intakes developed by the FNB based on age and sex suggest the following recommended intakes.
Recommended Dietary Allowances for Magnesium
|Birth to 6 months||30 mg||30 mg|
|7-12 months||75 mg||75 mg|
|1-3 years||80 mg||80 mg|
|4-8 years||130 mg||130 mg|
|9-13 years||240 mg||240 mg|
|14-18 years||410 mg||360 mg||400 mg||360 mg|
|19-30 years||400 mg||310 mg||350 mg||310 mg|
|31-50 years||420 mg||320 mg||360 mg||320 mg|
|51+ years||420 mg||320 mg|
Popular food sources of magnesium
|Food||Milligrams (mg) per serving||Percent DV|
|Almonds (dry roasted), 1 ounce||80||20|
|Spinach (boiled), 1/2 cup||78||20|
|Cashews (dry roasted), 1 ounce||74||19|
|Peanuts (oil roasted), 1/4 cup||63||16|
|Soy milk (plain or vanilla), 1 cup||61||15|
|Black beans (cooked), 1/2 cup||60||15|
|Edamame (shelled, cooked), 1/2 cup||50||13|
|Peanut butter (smooth), 2 tablespoons||49||12|
|Bread (whole wheat), 2 slices||46||12|
|Avocado (cubed), 1 cup||44||11|
|Potato (baked, with skin), 3.5 ounces||43||11|
|Rice (brown, cooked), 1/2 cup||42||11|
|Yogurt (plain, low fat), 8 ounces||42||11|
|Breakfast cereals, fortified with 10% of the DV for magnesium||40||10|
|Oatmeal (instant), 1 packet||36||9|
|Kidney beans (canned), 1/2 cup||35||9|
|Banana, 1 medium||32||8|
|Salmon (cooked), 3 ounces||24||6|
|Milk, 1 cup||24-27||6-7|
|Halibut (cooked), 3 ounces||24||6|
Benefits of magnesium supplements
#1: Exercise and recoveryAs a dietitian, it is commonly heard from patients who are work out enthusiasts that they feel great post workout, but they cannot understand why they feel sluggish the day after. Well, it may have to do with their magnesium levels. One study of 23 competitive triathletes who were given magnesium supplements over four weeks found their swim, bike, and run times had improved versus those given just a placebo, and they also had a reduced stress response. 6 Our founder John experimented with magnesium supplements for a few weeks and noticed some improvements in mood and athletic performance. Though far from a competitive athlete, he did notice that he had less general aches and pains post-workout when supplementing with magnesium versus when he was not. Why might this be happening? In a study in rats (so take with a grain of salt) Magnesium has been shown to help dispose of the number one culprit of post workout soreness: lactic acid. 7 Exercise redistributes the magnesium in the body in order for it to be more effectively used during this period of oxidative stress. The body tends to excrete more magnesium through sweat and urine during physically active states, which may increase magnesium requirements by 10-20%
#2: Mood boosterWhile John doesn’t suffer from depression, magnesium seemed to give him a mood boost. He noted that his mood felt pretty uplifted during his three week experience using magnesium, with the exception of days he forgot to take it. Was this just a placebo? Maybe, there are studies which indicate magnesium can be a mood booster. Because magnesium is critical to brain health, researchers think it may have a big effect on those with depression — in fact, they’ve known this for 100 years or longer. 9 Adults with depression have been found to be low on the intake of magnesium. 10 One study of two dozen older adults with depression and a magnesium deficiency found that magnesium supplements worked just as well for treatment as an antidepressant. 11 Definitely something to be said for a potential natural alternative to medications that can come with a wide range of unpleasant side effects.
#3: Relieve PMS symptomsMagnesium has been shown to reduce some of the symptoms of premenstrual syndrome (PMS), including irritability, cramps, bloating, and general fatigue. One study of women (24-39) found that after taking magnesium supplements for 2 months and two menstrual cycles, the women recorded fewer mood changes, 12 while another two-cycle study showed reduced weight gain, fluid retention, and breast tenderness among participants who took 200 mg of magnesium daily. 13
#4: Reduces anxiety and promotes sleepMagnesium can help reduce anxiety, calm you down, and in general help you get to sleep. If you don’t feel refreshed after waking up, it typically means something is going wrong while you sleep. Maybe you’re not getting enough of the good stuff, like REM or deep sleep, or you’re not sticking to a schedule to help your body’s circadian rhythm. Whatever it may be, nutrient intake can affect sleep. Sleep efficiency, sleep time, and melatonin production have all been shown to increase as we take in more magnesium. 14
#5: Can relieve constipationWhen you’re constipated, you’d think that fiber has everything to do with it. Not true. It could be magnesium and how much you’re getting. In a study of nearly 4,000 Japanese women (ages 18 to 20 and dietetic students), more than 1 in 4 were found to have functional constipation — constipation without a physical cause. Their dietary fiber and water intake were not associated with this condition, but low magnesium intake was. 15 A healthy microbiome can have a big effect on overall health. In addition to constipation, magnesium deficiencies also have been shown to alter gut microbiota in mice, inducing anxiety and depressive behavior — tying a few of these top five benefits together. 16 While we generally don’t bring bathroom talk onto Gene Food, John noticed his gut has felt in tip-top shape the past 3 weeks. Probably partly diet, but maybe thanks to magnesium!
Are there any side effects of taking magnesium?In a word, yes. Magnesium is the primary ingredient in some laxatives, and also used in some medicines that relieve heartburn and indigestion symptoms. So it’s natural that, if you are getting a lot of magnesium from your food and taking supplements, to pass the recommended daily amount. may feel some side effects, including:
- Stomach discomfort
Who should consider magnesium supplements?Generally, if you’re otherwise healthy, you won’t experience any real symptoms of a magnesium deficiency other than loss of appetite, nausea, vomiting, fatigue, weakness .People with certain health conditions or chronic alcoholism may have more serious symptoms such as, muscle cramps, seizures, coronary spasms, and even personality changes. So for a person like John , magnesium supplements were an extra “feel-good” added into his daily routine that helped him feel better while exercising and sleeping. People at risk of a magnesium deficiency who may want to consider supplements after speaking with a doctor include: 17
- Those with gastrointestinal diseases, including Crohn’s disease and celiac disease;
- Those with type 2 diabetes or who are insulin-resistant;
- Those with alcohol dependence;
- Those who are older, as our gut absorbs less magnesium as we age while our kidneys also excrete more. 18