What You Will Learn
In this lesson, you will learn about the two main groups of minerals - major minerals and trace minerals. You will learn why minerals are important. You will also learn which foods are the best sources of the minerals. You will learn about the minerals that are required to be on the nutrition label - sodium, calcium and iron.
Introduction
Do you want to be as healthy as you can when you get older? Do you want to stay at about the same height as when you reached adult height? Do you want your bones to stay as dense as possible and be less likely to fracture? You don't want your bones to become more porous and break more easily or lose height and get curvature of the spine as you get older.
Hip fractures cause the greatest health problems and the most deaths. Half of all elderly adults hospitalized for hip fracture cannot return home or live independently after the fracture. Breaking a hip is one of the leading causes of admissions into a nursing home. Elderly people are more likely to die within six months to one year once they have broken a hip, mainly because of immobility and complications arising from immobility, as well as from the increased strain on the heart and other body organs.
We want to stay as mobile as we can for as long as we can to be able to take care of ourselves in our old age. Maintaining healthy bones is critical in preventing bone fractures and in staying more mobile.
To stay mobile, we also need to keep our muscles in good working order. We can do that by doing some weight bearing exercises and getting the minerals we need by eating mineral-rich food, Both bones and muscles have important roles in mobility and flexibility. Minerals play a key role in bone health and in muscle function. Muscles can't contract without certain minerals.
Minerals are also important for our heart and circulatory system to function as they should. Minerals are important for our heart to beat regularly and to help prevent a buildup of fluid in our feet or other body parts. Excessive fluid buildup increases the workload on our heart.
Do you eat enough low fat meats, fruits, vegetables, milk and other foods that are our best sources of minerals? Minerals are very important, but tend to be low in our diet. According to the 2005 Dietary Guidelines for Americans, intake levels of the following minerals may be of concern for adults, adolescents and children: calcium, potassium and magnesium. Likewise, intake of iron is a concern for women of childbearing age who may become pregnant. Be sure to include mineral-rich foods such as low fat meats, fruits, vegetables, milk and others.
We want to be as healthy as we can be for as long as we live. If we eat a poor quality diet that lacks minerals, the result is poor bones that become brittle and break easily, we are at an increased risk for heart complications which can result in swelling in our feet, legs or other parts of our body.
USDA Food Guide Review
A balanced diet that provides a variety of foods is the best guarantee of our getting all essential nutrients. Use the USDA Food Guide in planning a menu for each day. Make sure you include foods from from all food groups. Get the recommended number of servings from each food group since no food group contains all of the nutrients needed. The number of servings from each food groups depends on person's age, gender and physical activity level.
What Are Minerals?
Minerals are a group of nutrients needed by your body. They are important in regulating body processes and in giving your body structure. Have you ever experienced swelling in your fingers, ankles or feet? Minerals have an important role in keeping a healthy fluid balance. Minerals are also needed for your muscles to work proprerly and for impulses to be carried over the nerve pathways. Certain minerals help form bones. Bones make up the structure of your body. With such important jobs, we need to be sure to eat foods rich in this important group of nutrients.
Minerals can be classified into two main groups, based on how much you need. You need all the minerals though, no matter whether you need just a little or a lot. Major minerals are those needed in amounts of more than 250 milligrams (mg) daily. Calcium, phosphorus and magnesium are in this group, along with three electrolytes - sodium, chloride and potassium. Trace minerals are those needed in very small or trace amounts of less than 20 mg daily. These include chromium, copper, fluoride, iodine, iron, manganese, molybdenum, selenium and zinc. This lesson will focus on the minerals required on the nutrition label. They include sodium, calcium and iron.
Sodium
Sodium is one of the most plentiful minerals in the body. Sodium is chiefly found in the fluids that circulate outside the cells, and only a small amount of it is inside the cells. We need to understand a little about the relationship between sodium and potassium to understand how sodium functions in our body, because they work as partners. Potassium, another mineral, is located mainly inside the cells. The interrelation between these minerals and their concentrations permits fluid to pass back and forth between the cells and the surrounding areas. This movement of fluids across cell membranes is called osmosis.
Sodium and potassium are important in keeping a normal balance of water between the cells and the fluids. A lowering in the sodium content of the fluids results in a transfer of water from the fluids into the cells. An increase in sodium causes a transfer of water from the cells into the fluids. All types of muscles including the heart muscle are influenced by sodium and potassium. Although potassium is important, it is not required to be listed on the nutrition label.
Sodium is needed for nerves and muscles to function as they should. Sodium helps maintain normal blood volume and blood pressure. It occurs naturally in many foods. Sodium is added during processing to foods to preserve or in flavorings. We need some sodium, but we need to be careful not to get too much sodium. Getting too much sodium increases our risk of high blood pressure. The higher the salt (sodium) intake, the higher the blood pressure. Keeping blood pressure in the normal range helps reduce the risk of
coronary heart disease, stroke, congestive heart failure and kidney disease. A person might experience fluid retention or swelling with high intake of sodium. Decreasing salt intake is advised to reduce the risk of high blood pressure.
Sodium is required nutrient on the nutrition facts panel. The 2005 Dietary Guidelines for Americans recommends consuming less than 2,300 mg (1 teaspoon of salt) of sodium per day. Many Americans consume substantially more. People with hypertension, African-Americans and middle-aged and older adults should aim to consume no more than 1,500 mg of sodium per day. Foods that are low in sodium are those containing less than 140 milligrams or 5 percent of the Daily Value (DV).
We get excess sodium in our diet from table salt, soy sauce and monosodium glutamate. Table salt is 40% sodium. The natural salt content of foods accounts for only about 10 percent of our total sodium intake. To keep sodium intake within a healthier level, avoid highly salted foods and remove the salt shaker from the table. About 5 percent to 10 percent of the total salt we eat comes from salt added at the table or while cooking. About 75 percent comes from processed food with added salt. Foods served by restaurants may also be high in sodium.
Read the labels on canned, frozen and instant foods. Many are high in sodium. Unprocessed, whole foods are lower in sodium - and higher in potassium- than processed foods. Don't use taste as a guide to how much sodium the food contains. Many foods high in sodium don't taste salty. For example, some cereals don't taste salty, yet cocktail peanuts do; however, those cereals may have more sodium in them than the peanuts. Salt has been added to the outside of the peanuts and our taste buds pick up on that. Read the labels to be sure! A good guideline to follow is to choose and prepare foods with little salt while consuming potassium-rich foods such as fruits and vegetables. A potassium-rich diet blunts the effects of salt on blood pressure, may reduce the risk of developing kidney stones and may decrease bone loss with age. The recommended intake of potassium for adolescents and adults is 4,700 mg/day.
The government definitions for sodium on the nutrition label are:
Label Claim Definition - Per Standard Serving Size
Sodium Free: Less than 5 mg sodium
Very Low Sodium: 35 mg or less sodium
Low Sodium: 140 mg or less sodium
Reduced Sodium: At least 25 percent less sodium
Light in Sodium: 50 percent less sodium
To avoid too much sodium:
• Enjoy foods without added salt.
• Cook most foods with only small amounts of added salt.
• Add little or no salt to food at the table.
• Eat pickles, olives and other pickled foods less often.
• Cut back on eating salty or smoked meats such as lunch meats and franks, or select the lower-salt choices.
• Select food products prepared with less sodium.
• Read labels for sodium content. Look in the list of ingredients for words that would tell you if sodium is in that food: soda, sodium or the symbol for sodium, Na. Examples would be sodium bicarbonate for baking soda, monosodium glutamate, di
-sodium phosphate and others.
• Eat plenty of fresh fruit and vegetables.
Calcium
Calcium content of food is required on the nutrition label. Calcium has many important uses in the body. It is an important mineral in building bones and teeth. High dietary intake of calcium at maturity helps keep bones strong by slowing the rate of bone loss that can occur with aging. If you get a cut that bleeds, the clotting that occurs is due to calcium. Calcium is important for maintaining regular heartbeat. It is also necessary for muscle contraction as well as maintaining healthy cell membranes. As you can see, calcium is a very important mineral, yet many of us don't get the amount of calcium that we need.
Calcium is found in three classes of food - milk and milk products, green vegetables and a few fish and shellfish. Calcium absorption is enhanced by vitamin D, phosphorus and lactose in milk. A high protein diet leads to increased losses of calcium. When we increase our fiber intake, we need to increase our calcium intake also since fiber decreases the absorption of calcium. We need the fiber, though, for its beneficial effects.
There are tools that can help us determine if we get the amount of calcium we need. One is the USDA Food Guide and the other is the nutrition facts panel on food labels. If we get the recommended number of servings of each of the basic food groups in the USDA Food Guide, we will get enough calcium. The 2005 Dietary Guidelines for Americans encourages consuming 3 cups of fat-free or low-fat milk or equivalent milk products each day to get the proper of amount of calcium. On the nutrition facts panel, the daily reference value for calcium is one gram. The lesson on milk provides more information on calcium.