Healthy Eating: Mighty Minerals
In This Article:
What Are Minerals?
Minerals are different from vitamins in that they do not contain carbon. This makes them inorganic compounds. They cannot be destroyed as easily as vitamins can by heat or poor handling. Minerals are involved in a variety of functions in the body. They help to both regulate body processes and give your body structure. Just like vitamins, minerals are only needed in small amounts.
All minerals are absorbed into your intestines and then are transported and stored in your body in various ways. Some minerals pass directly into your bloodstream, which transports them to the cells; the excess passes out of the body through the urine. Other minerals, such as calcium, attach to proteins and become part of your body structure (in the case of calcium, the bones). Because these types of minerals are stored, large amounts taken for a long period of time can be harmful.
More than sixty minerals are found in the body. Of those, twenty-two are considered essential to good health. Minerals are divided into two categories: major and trace. As the names imply, major minerals are required in larger amounts than trace minerals.
Potassium is an electrolyte that works closely with its counterparts, chloride and sodium. Over 95 percent of potassium is in the body's cells. Potassium helps regulate the flow of fluids and minerals in and out of the body's cells. It also helps maintain normal blood pressure, maintain heart and kidney function, and transmit nerve impulses and contraction of muscles. Potassium is very important in converting blood sugar into glycogen, the storage form of blood sugar in your muscles and liver. A potassium shortage in the muscles can produce great fatigue and muscle weakness.
A potassium deficiency is unlikely for most healthy people because this mineral is so widely available in foods. Deficiency could occur as a result of chronic diarrhea, vomiting, diabetic acidosis, kidney disease, or prolonged use of laxatives or diuretics. Symptoms of potassium deficiency include weakness, loss of appetite, nausea, and fatigue.
Most people can handle excess potassium because it is excreted in the urine. If the excess cannot be excreted—for instance, in the case of someone with kidney disease—it can cause heart problems. These people will most likely be advised by their doctors to limit foods containing potassium.
ALERT! If you need to limit your potassium content, be aware that salt substitutes contain potassium chloride instead of the sodium chloride that is in table salt.
There is no RDA or DRI for potassium, but the minimum amount suggested for adults is 2,000 milligrams per day. Some experts recommend a higher intake, around 3,500 milligrams per day, to help protect against high blood pressure.
Potassium is found in a wide range of foods, but especially in fruits and vegetables as well as fresh meat, poultry, and fish. It is important to have a proper balance of potassium and sodium in the diet. Studies have indicated a possible link between a diet high in sodium and low in potassium with an increased risk of cancer, heart disease, high blood pressure, and stroke. On the other hand, a diet high in potassium and low in sodium may help to protect or decrease the risk for these health problems.
Sodium is also an electrolyte that works closely with potassium and chloride. In contrast to potassium, most of the body's sodium is found outside the cells in blood and other body fluids. There is a pump in the membrane of all cells that flushes sodium out of and brings potassium into the cell. If sodium is not pumped out properly, water accumulates in the cell, causing it to swell.
Sodium helps regulate the movement of body fluids in and out of cells. It also helps relax your muscles (including your heart muscle), transmit nerve impulses, and regulate blood pressure. Sodium can contribute to hypertension by raising blood pressure.
A sodium deficiency is unlikely except in cases of prolonged diarrhea, vomiting, fasting, starvation, or kidney problems. Symptoms can include nausea, dizziness, dehydration, muscle weakness, loss of appetite, and muscle cramps.
Healthy people excrete excess sodium. In the United States, the typical diet contains excessive amounts of sodium. Processed foods are one of the biggest contributors to our sodium intake. The rest comes from table salt and small amounts that occur naturally in foods. There is no RDA or DRI for sodium; however, the amount considered safe and adequate is 500 milligrams daily. Healthy American adults should reduce their sodium intake to no more than 2,400 milligrams per day. This is almost 1¼ teaspoons of sodium chloride or table salt each day.
Fact: The American Heart Association says that "reducing the amount of sodium you consume may help you reduce or avoid high blood pressure."
More on: Nutritional Resources for Families
Copyright © 2002 by Kimberly A. Tessmer. Excerpted from The Everything Nutrition Book: Boost Energy, Prevent Illness, and Live Longer with permission of its publisher, Adams Media Corporation.
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