Whatever do I need it for?

Magnesium is needed for more than 300 biochemical reactions in the body. It helps maintain normal muscle and nerve function, keeps heart rhythms steady, and bones strong. It is also involved in energy metabolism and protein synthesis.ⁱ

The presence of magnesium is found to have a positive influence on a variety of diseases, such as heart disease, osteoporosis, diabetes, and high blood pressure.ⁱⁱ

Is There Cause for Alarm?

Every year or so another alarm is raised about the lack of some nutrient in our diet and how this lack is the true underlying cause of large numbers of deaths from some well-known disease, such as heart attacks. This was the case with the selenium scare in Dead Doctors Don’t Lie, as well as the current frenzy over magnesium.

A website I visited while researching this article claimed that there is “an inverse relationship between water hardness and mortality from cardiovascular disease. That is, people who drink water that is deficient in magnesium and calcium generally appear more susceptible to this disease. The U.S. National Academy of Sciences has estimated that a nation-wide initiative to add calcium and magnesium to soft water might reduce the annual cardiovascular death rate by 150,000 in the United States.”ⁱⁱⁱ

The 150,000 represent only 9% of the at least 1,602,000 deaths from cardiovascular disease listed in the World Health organization’s statistics for 1998,^iv the latest year for which such statistics are available. While magnesium does play a role in the regulation of heart rhythms, among other metabolic functions, the greater amount of evidence shows that heart disease is generally caused by poor lifestyle practices, such as a high cholesterol diet and lack of exercise, not from mineral deficiency.

It’s estimated that the average American gets only 300 mg of magnesium a day, compared with the Recommended Dietary Allowance of 420 mg.^v The RDA for magnesium is age and gender specific.

Will adding mineral supplements to the drinking water really solve the magnesium deficiency problem for the average American? Here’s a comparison of drinking habits in the US versus Canada and Europe:^vi 

From the above table, it’s evident that the average American gets 34% of liquids from sources involving tap water, and 65% from sources that use purified water or are non-water sources. The Coca-Cola Company states that, “In 2000, the Company distributed approximately 4 billion unit cases (24 eight-ounce servings, or 192 ounces per case) of products in bottle, can, and fountain containers.”^vii Pepsi-Cola’s statistics indicate that the average American drinks 55 gallons of its carbonated soft drink products every year.^viii

What Causes Magnesium Deficiency?

Many things can cause a magnesium deficiency, such as gastrointestinal disorders (like excessive diarrhea and vomiting), the use of diuretics and some antibiotics, some cancer treatments, inefficient magnesium absorption in the intestines, and alcohol consumption. Magnesium is lost in the urine, so anything that causes excessive urination can also cause a deficiency. Poorly controlled diabetes also increases the loss of magnesium in the urine.^ix

Signs of magnesium deficiency include confusion, disorientation, loss of appetite, depression, muscle contractions and cramps, tingling, numbness, abnormal heart rhythms, coronary spasm, and seizures.^x 

Too Much of a Good Thing Can Hurt You Too

Very high doses of magnesium can be bad for you, too. It can trigger undesired affects such as diarrhea, which is probably why it’s used in laxatives. The elderly are more often at risk of magnesium toxicity because kidney function declines with age and they are more likely to consume laxatives and antacids with magnesium in them.^xi

Signs of excess magnesium can be similar to magnesium deficiency and include metal status changes, nausea, diarrhea, appetite loss, muscle weakness, difficulty breathing, extremely low blood pressure, and irregular heartbeat.^xii

The Diet Challenge

Is it possible to obtain sufficient quantities of this mineral to maintain good health from our everyday diet? If you eat right! Processed foods have a lot less magnesium in them unprocessed “whole” foods. White bread has only 6 mg of magnesium per slice, while whole wheat contains 24 mg in a single slice.xiii Green leafy vegetables, nuts, seeds and some grains are good sources of magnesium and provide a variety of taste and texture. A variety of these sources in the diet will ensure that you have enough of this mineral to satisfy your daily needs. Here are some great vegetarian sources of magnesium:^xiv

The Bottom Line

Even though some sources may be raising a fuss over magnesium, other sources indicate there is not a cause for alarm among healthy adults.

Even though dietary surveys suggest that many Americans do not consume magnesium in recommended amounts, magnesium deficiency is rarely seen in the United States in adults. When magnesium deficiency does occur, it is usually due to excessive loss of magnesium in urine, gastrointestinal system disorders that cause a loss of magnesium or limit magnesium absorption, or a chronically low intake of magnesium.^xv

Healthy adults who eat a varied diet do not generally need to take a magnesium supplement. Magnesium supplementation is usually indicated when a specific health problem or condition causes an excessive loss of magnesium or limits magnesium absorption.^xvi

i Facts about Dietary Supplements (NIH Clinical Center). Read this fact sheet

ii Ibid.

iii Dr. Harold D. Foster, “Groundwater and Human Health,” Groundwater Resources of British Columbia (Ministry of Environment, Lands, and Parks and Environment Canada, 1994): 6.1-6.3.

iv 2001 Heart and Stroke Statistical Update (American Heart Association.

v B.S. Hass and N.A. Littlefield, “Abstract # C-13,” Is the RDA for Magnesium Too Low? (NCTR, FDA, Jefferson AR 72079).

vi Beverage Digest LLC website. 

vii Coca-Cola Enterprises, Inc.

viii PepsiCo, Inc.

ix Facts about Dietary Supplements (NIH Clinical Center). Read this fact sheet

x Ibid.

xi Ibid.

xii Ibid.

xiii Jean A. Pennington, Bowes & Church’s Food Values of Portions Commonly Used (Lippincott Williams & Wilkins, 1997).

xiv Ibid.

xv Facts about Dietary Supplements (NIH Clinical Center). Read this fact sheet

xvi Ibid.