Many health 'experts' such as the National Institute of Health assume that magnesium deficiency is not common in N. America, because "magnesium, an abundant mineral in the body, is naturally present in many foods, added to other food products, available as a dietary supplement, and present in some medicines (such as antacids and laxatives)."
The same NIH article states that "Assessing magnesium status is difficult because most magnesium is inside cells or in bone".
Personally, no doctor has ever tested me for magnesium deficiency, or asked about my diet with regard to magnesium, or said that any health condition I might have could be related to low magnesium.
The University of Maryland Medical Center states that "most people in the United States probably do not get as much magnesium as they should from their diet", but that "it's rare to be truly deficient in magnesium. Certain medical conditions, however, can upset the body's magnesium balance."
The same article then lists a dozen common health conditions which are improved by increased magnesium intake, especially from food.
Since magnesium is a critical factor in hundreds of bodily functions, we don't seem to do well on a a diet that's low in magnesium.
It seems reasonable to suppose that mild to severe magnesium deficiency is actually common, given it's critical importance to our health, and the sad state of the American diet.
Because of poor diet, depleted soils, and environmental pollution, mineral deficiencies have steadily increased. A few perceptive souls have been aware of the problem since the early days of the last century.
Research and statistics presented by Ancient Minerals supports that viewpoint, which is shared by the ag industry, Dr. Mercola and other holistic health experts such as Joanne Brophy, who says:
"Magnesium deficiency is so common in North America that it should be considered epidemic. Magnesium is an integral component of every cell in the body. It is second only to potassium as the most abundant intracellular nutrient."
What are the symptoms of magnesium deficiency? I don't want to foster health obsessions, but it's possible to blame a lack of magnesium for just about any physical or mental symptom, from muscle cramp to heart failure, from PMS to chronic fatigue.
I've read that calcium deficiency is really magnesium deficiency, since the body can only absorb calcium in the presence of magnesium. Thus magnesium deficiency may be implicated in osteoporosis, for example.
Magnesium affects every part of the body - the nervous system, organs, skeletal system, all the muscles, the reproductive system, digestion and elimination, cardiovascular, vision -have I left anything out?
For a more detailed discussion of this topic, see the article by Michael Schachter M.D: The Importance of Magnesium to Human Nutrition
This isn't to scare you into running out and buying expensive dietary supplements, but to help increase awareness of magnesium in your diet. A healthy plant based diet will give you most of what you need, for magnesium and other minerals and vitamins.
Whole Foods has an excellent nutrient rating chart for magnesium, with a list of plant foods, serving sizes and calories, amount of magnesium per serving, percentage of daily requirement, overall nutrient density, and whole foods health rating - all excellent to good.
It's interesting that plant foods are the best sources of magnesium. Which leads to the obvious conclusion that vegetarians don't need to wory about magnesium deficiency. That's not quite true. How much magnesium you get on a veg diet depends on what plants and how much of them you eat, and how processed they are.
Magnesium defiency has also been associated with the use of diuretics, malabsorption of nutrients, excessive vomiting and diarrhea, poorly controlled diabetes, alcoholism, and long-term consumption of distilled or RO treated water.
No, I'm not kidding about the water!
Health conscious vegetarians are often inclined to drink lots of water, and herbal teas, made with water. They are generally concerned with the quality of drinking water, as are sensible people everywhere.
That may lead to the use of distilled or Reverse Osmosis treated water, both of which strip all minerals from the water. The mineral deficient water that you drink, or cook with, pulls minerals from your food and your body, instead of adding them. For more information, see the article by Bob McCauley, Purified Water and its Dangers.
Herbal teas can be a source of minerals, but strong herbal infusions are excellent sources of minerals. Refer to Rosemary Gladstar's Family Herbal for recipes.
All of the alternatives to drinking R.O. water have drawbacks. They may involve considerable on going expense, for carbon filters, spring water, mineral drops, or magnesium supplements.
Spring water is a non-renewable natural resource, and plastic containers clog landfills, and leach toxic chemicals into the water.
If you add mineral drops to your RO water, as we have done in the past, the question is how much minerals you actually absorb. That question applies to supplements in general.
As of 2011, we've used a simple carbon filter for tap water instead of using RO water. BTW, Brita filters are useless. We like the Mavea filters (same price) - very effective, and they fit the Brita containers.
However you do it, it's better to get minerals in your water than not. But it takes more than mineralized water to get enough magnesium in your diet.
Since the best sources of magnesium are plants (except for tuna), you might think that those who eat a plant based diet shouldn't have a problem getting enough magnesium. But how many of us eat enough of these healthy plant foods daily to be sure of getting enough magnesium?
One serving per day each of greens, nuts, seeds, legumes (e.g. black beans, tempeh, lentils), or whole grains will provide more than enough magnesium. But of course we actually have to eat those foods daily!
Consult Whole Foods excellent magnesium article for more detailed info on magnesium in human nutrition.
Check out the nutrient rating chart in the article to find out what and how much of which foods to include in your daily diet to get enough magnesium.