Chapter 4 – Magnesium: The Soothing Mineral
Did you know that mighty magnesium is responsible for over 300 biochemical reactions in your body? Some of the tasks magnesium does on a daily basis include maintenance of normal muscle and nerve function, steadying your heart rhythm and nerves, keeping your immune system strong and protective, and helping to maintain your bone density and strength, blood glucose control, and blood pressure regulation. (1)
You have almost a full ounce of magnesium in you, and half of that is in your bones, with the rest being in your soft tissues. Only a very small and specific amount (less than 1%) is in your blood.
Equilibrium is tightly controlled by the kidneys, and about 120 mg per day is excreted through urine. Amazingly, if you are low on magnesium your body headquarters will sense it and reduce excretion of it.
Though the amount of magnesium in your blood is very small compared to your bones, it is used as the gage to tell if you are getting enough, or too much. This makes the accuracy of such measurements questionable, as the majority of magnesium is in your cells and bones.
Other methods are also used such as measuring urine and saliva, but still there is uncertainty to the accuracy. This is why it is very important to self monitor for deficiency symptoms, which will be covered later.
|0 – 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|
*Adequate Intake (AI)
Foods Where Magnesium Lives
Generally speaking, foods that are high in fiber also contain magnesium. For the most part magnesium is found in many plants and animal products, and is added to things such as breakfast cereals and more – so it is readily available. Yet many still don’t get enough magnesium.
|Food||Milligrams (mg) per serving||Percent DV*|
|Almonds, dry roasted, 1 ounce||80||20|
|Spinach, boiled, ½ cup||78||20|
|Cashews, dry roasted, 1 ounce||74||19|
|Peanuts, oil roasted, ¼ cup||63||16|
|Cereal, shredded wheat, 2 large biscuits||61||15|
|Soymilk, plain or vanilla, 1 cup||61||15|
|Black beans, cooked, ½ cup||60||15|
|Edamame, shelled, cooked, ½ cup||50||13|
|Peanut butter, smooth, 2 tablespoons||49||12|
|Bread, whole wheat, 2 slices||46||12|
|Avocado, cubed, 1 cup||44||15|
|Potato, baked with skin, 3.5 ounces||43||11|
|Rice, brown, cooked, ½ cup||42||11|
|Yogurt, plain, low fat, 8 ounces||42||11|
|Breakfast cereals, fortified with 10% of the DV for magnesium||40||10|
|Kidney beans, canned, ½ cup||35||9|
|Banana, 1 medium||32||8|
|Salmon, Atlantic, farmed, cooked, 3 ounces||26||7|
|Milk, 1 cup||24-27||6-7|
|Halibut, cooked, 3 ounces||24||6|
|Raisins, ½ cup||23||6|
|Chicken breast, roasted, 3 ounces||22||6|
|Beef, ground, 90% lean, pan broiled, 3 ounces||20||5|
|Broccoli, chopped and cooked, ½ cup||12||3|
|Rice, white, cooked, ½ cup||10||3|
|Apple, 1 medium||9||2|
|Carrot, raw, 1 medium||7||2|
Could YOU Be Magnesium Deficient?
Magnesium deficiency is fairly uncommon because of the impressive ability of our body to deal with shortages. When you are consuming too little magnesium from your diet, as mentioned previously, your body chooses to excrete less of it through urine, as a method to conserve what it can. However, even this remarkable rationing system can only succeed for so long. Because chronic long term low intake of magnesium, or alcoholism or using certain medications leach minerals to a greater degree than your body can compensate for.
Magnesium deficiency is so dangerous, because the initial symptoms of appetite loss, nausea, vomiting lead to even greater deficiency. The next more serious stage is increased fatigue, weakness, personality changes, muscle contractions and cramps, numbness, tingling, seizures,abnormal heart rhythms, and coronary spasms.
- Dietary Reference Intakes: Calcium, Phosphorus, Magnesium, Vitamin D and Fluoride. Washington, DC: National Academy Press, 1997.
- U.S. Department of Agriculture, Agricultural Research Service. USDA National Nutrient Database for Standard Reference, Release 25. Nutrient Data Laboratory Home Page, 2012.