Magnesium keeps us moving, thinking and behaving normally. Magnesium is a cofactor for more than 300 enzymes involved in the metabolism of food components and many products such as protein synthesis. It balances calcium in the body to maintain normal muscle and nerve function and works in concert with calcium to keep bones strong. It keeps heart rhythm steady and supports a healthy immune system. Magnesium is required for parathyroid hormone secretion, helps regulate blood sugar levels and promotes normal blood pressure.1
Studies show that magnesium deficiency is common in those with celiac disease. One study found that magnesium deficiency was present in all patients with classical celiac disease, 1/5th of persons with silent celiac disease and 1/5th of persons with celiac disease on a gluten-free diet. Another study found that deficiency was present in all patients with asymptomatic celiac disease and that bone mass was reduced.2
5 Important Reasons to Be on the Lookout for Magnesium Deficiency:
- 1. It can make life miserable, causing chronic fatigue, weakness, lousy appetite, vomiting, constipation, poor memory, headache and trouble sleeping.2. It can disturb the mind, causing irritability, anxiety, sadness that can deepen into depression, premenstrual tension, confusion and personality change.
3. It can cause pain in bones and in muscles with twitching and spasm that can worsen into tetany.
4. Chronic deficiency compromises the strength of bone leading to osteoporosis (weak bones) and impairs the secretion and action of parathyroid hormone, which in turn, causes low blood calcium with all its effects.
5. Serious deficiency can threaten the heart and arteries, as a cause of hypertension, cardiac dysrhythmias (irregular heart beat) and myocardial ischemia (not enough oxygen to the heart muscle).
How Magnesium Works in the Body
1. Role of magnesium in muscle function. In muscle contraction, the mineral potassium moves from inside muscle fibers out into the fluid surrounding them while the mineral sodium moves from the fluid surrounding cells into the muscle fibers. This exchange is reversed when muscle fibers relax. Calcium acts as the catalyst for contraction. Magnesium acts as the catalyst for relaxation. With a magnesium deficit, muscles cannot properly relax, causing weakness, spasm and pain.
2. Role of magnesium in digestion. Part of digestive function is to move food from the mouth through the esophagus and stomach to the intestines and out the anus. A magnesium deficit impairs the musculature of the gastrointestinal tract. This is the cause of constipation, nausea, vomiting and other digestive symptoms stemming from poor muscle movement.
3. Role of magnesium in bone health. Approximately 50% of total body magnesium is found in bone. Along with calcium and certain other nutrients, magnesium provides strength to the living bone tissue. With a magnesium deficit, this mineral will be pulled out of bone tissue for more vital functions elsewhere. This is a cause of osteoporosis.
4. Role of magnesium in nerve and mental function. Nervous tissue is sensitive to low levels of magnesium. The resulting impaired nerve conduction causes fatigue, weakness, and tremors. The mind requires magnesium for adequate neurotransmitter chemicals. Magnesium deficit can result in insomnia, faulty thinking, emotional problems, inappropriate behavior, and psychiatric problems but not dementia. Adequate EPA ( an omega-3 fatty acid) depends in part on magnesium as a co-factor. EPA deficit causes its own set of nervous problems.
5. Role of magnesium in heart health. The heart is a muscle that depends on magnesium for relaxation following contraction. Serious magnesium deficiency causes poor heart action and strength and further stresses the heart by causing hypertension. That is, blood pressure rises because the muscle layer of artery walls cannot properly relax, constricting the arteries. Narrowed arteries in turn force the heart to pump harder to get the blood through them. Magnesium deficit is implicated in heart attack.
6. Role of magnesium in parathyroid health. The four small parathyroid glands sit next to the thyroid gland in the neck. Their function is to maintain a balance of calcium. When calcium is needed and not forthcoming from absorption in the small intestine, parathyroid hormone acts to remove calcium from bone to meet essential body needs. Inadequate magnesium impairs this function.
Only 1% of magnesium is found in blood, but the body must keep blood levels of magnesium constant.
Dietary magnesium may be absorbed along the entire length of the small intestines but most absorption occurs in the middle section, the jejunum. In celiac disease, malabsorption is caused by the binding of magnesium to unabsorbed fat, which pass together out of the body. If steatorrhea (fat malabsorption) continues on a gluten-free diet, magnesium and certain other minerals such as calcium will not be adequately absorbed. An inexpensive stool test can show fat malabsorption. Supplementation would be needed. This mineral is excreted through the kidneys.
Recommended Daily Allowances
The amount of magnesium required every day by children 1 to 3 years is 80 mg. and 130 mg. for children age 4 to 8 years. Boys and girls 9 to 13 years need 240 mg. Adolescent boys 14 to 18 years need 410 mg. and girls need 360 mg. Men 19 to 30 years need 400 mg. and women 310 mg. Older men need 420 mg. and women need 320 mg. Pregnant women need 400 mg.1
Food Sources of Magnesium
Magnesium is richest in seeds, nuts, grains, certain fish, seafood and leafy vegetables. There are small amounts in many food sources, making a varied diet important. Specific food sources provided by USDA (US Dept of Agriculture) are listed below. Note: a cup of wheat flour has only 22mg of magnesium…no loss here!
Food Magnesium Content (mg)
Flours, 100g or about a cup:
Rice bran 781 (Always cook or bake bran to destroy natural
phytate because it binds nutrients.)
Cottonseed flour 716
Soy flour 369
Brown rice flour 112
Corn flour, masa 110
Conch, 100g 238
Pumpkin/ squash seeds, ¼ cup 180
Peanut butter, 2 tbsp. 150
Sunflower seeds, ¼ cup 148
Unsweetened chocolate, 1 oz.square 110
Salmon, Chinook, 100g 122
Beans, 100g 111
Halibut, 100g 107
Oyster, 100g 97
Spinach/ Swiss chard, ½ cup 87
Mixed nuts, 21 pieces 80
Tuna, 100g, about ½ cup 64
Storage, Processing, and Cooking
Processing of whole grains strips them of their germ and bran layer, which contains magnesium and many other nutrients. The remedy is to buy and consume rice bran and more whole grains, such as brown rice and buckwheat that can be added to cooked cereals, baked goods, meat loafs and such.
Cooking can substantially reduce the magnesium in foods such as dried beans and leafy green vegetables. The remedy is to consume the liquid used for cooking rather than pouring it away. Making soups, stews, pot roasts and casseroles are excellent ways to preserve magnesium in food preparation. Nuts and seeds lose very little magnesium in roasting or making into butters.1
Tests and Treatment
Tests for magnesium deficiency involve blood analysis of magnesium and the much more expensive test, intracellular free magnesium levels. At present they are not completely reliable.
Treatment is directed at the cause of the deficiency. In celiac disease, it would be a magnesium-rich gluten-free diet that may require the addition of oral supplement.
Supplements Can Be Toxic
While toxicity is not known to occur by consuming food, large dose magnesium supplements (1000-5000 mg/day) are toxic. Too much supplemental magnesium causes diarrhea, lethargy and weakness.
Medications that interfere with the body’s supply of magnesium include the diuretics thiazide and furosemide, the antibiotics erythromycin, sulfamethoxazole, neomycin, tetracycline, and sulfonamides, the blood thinner warfarin, oral contraceptives (birth control pills), corticosteroids (anti-inflammatory drug), and cyclosporine.
1. Krause’s Food, Nutrition & Diet Therapy. 10th Ed. W B Saunders Company, 2000.
2. Libonati, Cleo. “Recognizing Celiac Disease.” GFW Publishing Company, 2007.
Author Information: Cleo Libonati, RN, BSN
*Cleo Libonati is president/CEO and co-Founder of Gluten Free Works, Inc. www.glutenfreeworks.com. She is the author of Recognizing Celiac Disease. www.recognizingceliacdisease.com. She can be reached at firstname.lastname@example.org.