MINERALS - your good health!

Why You Need Calcium
Calcium is by far the most abundant mineral in your body. It makes up about 2 percent of your total body weight, or between 2 and 3 pounds if you're an average adult. Most of your calcium-98 percent of it-is in your bones. Another 1 percent is in your teeth, and the last 1 percent circulates in your blood. Small as the amount of calcium in your blood is, it's very important-so important that your body will pull calcium from your bones to make sure there's enough in your blood. Among other things, calcium helps regulate your heartbeat, control your blood pressure, clot your blood, contract your muscles, and send messages along your nerves. Calcium is needed to make many different hormones and enzymes, especially the ones that control your digestion and how you make energy and use fats. It also helps build your connective tissue and may help prevent high blood pressure and colon cancer.

How many bones are in your skeleton? Give up? You have 206. Every single one of them is made up mostly of calcium phosphate, a very hard, dense mixture made when calcium and phosphorus combine. Your bones may be hard, but they're also living tissue. You're constantly breaking down old bone and building new bone. From the time you're born until you get to be about 30 to 35 years old, you build up bone faster than you lose it, so your bones get bigger and denser, and you reach what's called peak bone mass. You could think of it as building up a bone savings account. After about age 35, you start to slowly break down bone faster than you can rebuild it-you start to draw on your
saved-up bone. Some slow bone loss is a normal part of getting older, but if you don't get enough calcium, the process can start to happen too fast, especially in older women who've reached menopause. If you lose too much bone, you empty out your bone savings account. At that point, your bones are thin, brittle, and break very easily. You've got osteoporosis.
Here's where calcium comes in. If your bones are strong to begin with, and if you keep giving them plenty of calcium as you get older, you'll help keep your bones strong throughout your life. And even if osteoporosis has already set in, calcium may help slow it down.
We'll be talking a lot about the role of calcium in preventing and treating osteoporosis. That's because osteoporosis is a very serious health problem. It affects some 25 million Americans-four out of five of them older women-and costs nearly $14 billion a year. You need
calcium now to avoid the crippling broken bones osteoporosis can cause.

If sometimes you feel like a nut, go for it! Nuts are high in magnesium, and this magnificent mineral helps maintain your maximum health. Magnesium makes your muscles relax-and that plays a big role in keeping your heartbeat healthy and holding down your blood pressure.
Today many doctors have realized that magnesium makes a big difference for some patients. Magnesium is getting to be a mainstream medication for people with migraines, asthma, and diabetes. Getting enough magnesium helps these people control their medical problems. Magnesium has one other major mission: Working with calcium, it helps keep your bones strong throughout your life.

Why You Need Magnesium
Every single cell in your body needs magnesium to produce energy. You also need magnesium to make more than 300 different enzymes, to send messages along your nerves, to make your muscles relax, to maintain strong bones and teeth, help your heart beat, and to keep your blood pressure at normal levels. Magnesium seems to help some health problems, such as asthma and diabetes, and can be very valuable for treating heart rhythm problems. You also need magnesium to use other vitamins and minerals properly. Vitamin C and calcium both work better, for example, when there's plenty of magnesium around.
To do all that, you need a fair amount of magnesium. In fact, your body contains about 25 grams of magnesium. Most of it's in your bones and eeth, but you also have a lot in your muscles and blood. The amount in your blood is very important for keeping your body's functions in balance. Just as you need calcium to make your muscles contract-when your heart beats, for example-you need magnesium to make them relax again. That's why the levels of calcium and magnesium in your blood have to be steady and why you need to be sure you're getting enough of both. If you don't have enough of them, your body will pull these minerals from your bones and put them into your blood-which can lead to weakened bones.

Look up zinc in the encyclopedia and you'll learn all about this important industrial metal. You'll learn about how it's used to make pipes and galvanized metals that resist corrosion. You'll learn that 6.8 million metric tons of zinc are used every year. You might even learn that there are 338 zinc mines in the world. What you won't learn is that the same stuff that galvanizes metal is also incredibly important for your health.
Zinc is very important for your immune system. In fact, if you have a bad cold, taking extra zinc could get you back on your feet several days sooner. Zinc also helps you heal quickly from wounds, keeps your skin healthy, helps preserve your eyesight, and might even improve your memory. It's no surprise that today many doctors and nutritionists tell their patients to "think zinc!"

Why You Need Zinc
Over 200 different enzymes in your body depend on zinc to work properly. Here's just one example: You need zinc to make the enzyme alcohol dehydrogenase, which breaks down alcohol. If you're deficient in zinc, your body can't process alcohol and you get very drunk on just a small amount.
You also need zinc to make many hormones, including the ones that tell your immune system what to do when you're under attack from germs. Zinc is essential for making the hormones that control growth and for the important male hormone testosterone. You have some zinc in every one of your body's cells, but most of it is in your skin, hair, nails, and eyes-and in your prostate gland if you're male. All told, your body contains just over 2.2 grams of zinc.

Iron barely qualifies as a trace mineral, because you have just under a teaspoon of it in your body. You need it chiefly to carry oxygen in your blood. Every one of your red blood cells contains a protein called hemoglobin-and four atoms of iron are attached to every hemoglobin molecule. In your lungs, oxygen molecules attach to the iron atoms and are carried to your cells. When the oxygen reaches its destination, it's swapped for the waste carbon dioxide and carried back to your lungs. You get rid of it by exhaling.
How much iron you have determines how much oxygen gets to the rest of your body. Not enough iron, and you start making fewer red blood cells. Not enough red blood cells, and you become anemic-weak, tired, pale, short of breath. Just how common is "iron-poor blood"? Not as common as all the advertising says, but common enough to be concerned. You could be low on iron for a long time before you become anemic. An important 1997 study found that one out of ten American women and smal l children were deficient in iron-or about 700,000 toddlers and 7.8 million women! Of those, about 240,000 toddlers and 3.3 million women were anemic. The results were so shocking that a national screening program for iron deficiency is being considered. Babies and toddlers need plenty of iron because they're growing so fast-and if they don't get it, they may fall behind in their mental development and never catch up.
Teenaged girls need extra iron for growth, while women in general need extra iron to make up for the blood lost each month to menstruation. Pregnant and nursing women also need extra, because they're passing a lot of their iron on to their babies. Anyone, male or female, who is very athletic also needs extra.

You need iodine to make the thyroid hormones that regulate your body's metabolism. In fact, that's all iodine does for you, but it's a lot: Those thyroid hormones play a big role in your growth, cell reproduction, nerve functions, and how your cells use oxygen. One of the hormones, thyroxin,
regulates how fast you use the energy from your food. If you don't have enough iodine, your thyroid swells up in an effort to make more hormones, a condition called hypothyroidism. The swelling is called a goiter.
The RDA for Iodine
In total, you have between 20 and 30 mg of iodine in your body. The RDA is more than adequate to prevent a deficiency.
Until well into this century, iodine deficiency was a serious problem. People living in the Midwest and Great Lakes region, where the soil is very low in iodine, didn't get enough in their diets and often got goiters. Iodine deficiency during pregnancy causes a severe form of mental retardation called cretinism. To solve the iodine problem, in 1924 American salt producers began adding iodine to table salt at the rate of 400 mcg per teaspoon. Goiter and cretinism soon disappeared as public health problems and today iodine deficiency is very, very rare.
Iodine is added to a lot of daily multi supplements, but it's not really needed, because most people get more than enough from the salt in their food. Too much iodine (over 25 times the RDA) can also cause a goiter. More than 1,000 mg a day may also cause acne flare-ups in some people.

One of the hottest supplements today is chromium picolinate. Diabetics swear it helps them control their blood sugar better. Body builders swear it helps them build muscle faster. Some people claim it helps lower high cholesterol, while others claim it boosts your production of the anti-aging hormone DHEA.
Is chromium such a miracle mineral? Maybe, for some diabetics-but the other claims don't hold up as well. Let's start with how much chromium you really need. Nobody knows. The Safe and Adequate range for adults is anywhere between 50 and 200 mcg. Why do you need it? In ways we still don't fully understand, chromium is involved with using fats, proteins, and carbohydrates. It's also needed to help the hormone insulin deliver glucose to your cells.
Because of the insulin connection, chromium is often touted as a way for diabetics to control their blood sugar. Chromium does seem to help some people with Type II, or adult-onset, diabetes, get glucose into their cells better. We suggest you skip chromium supplements and try to get between 50 and 200 mcg a day from your food. If you decide to try supplements, talk to your doctor first and keep a close eye on your blood sugar.
What about all those other things chromium is supposed to do? There's not a lot of evidence to back up the cholesterol or DHEA claims (see Chapter 27 on natural hormones for more on DHEA). The body builders may be disappointed too. The studies that showed chromium helps you lose fat and build muscle were badly flawed, and researchers haven't been able to reproduce them. It's relatively easy to get at least 50 mcg of chromium a day from your food. Apples, broccoli, barley, corn, beef, eggs, nuts, mushrooms, oysters, rhubarb, tomatoes, and sweet potatoes are all good food sources. Most good daily multi supplements also have some chromium in them. If you decide to take a chromium supplement to help your diabetes, choose chromium glycinate or the patented type of trivalent chromium picolinate called Chromax-II GTF. (The GTF stands for glucose tolerance factor.) Skip supplements made with chromium chloride-you don't absorb this form very well.

Your body's most abundant natural antioxidant is an enzyme called glutathione peroxidase. Now we'll just mention that without selenium, you can't make glutathione. A recent major study has shown that selenium can be a powerful cancer-prevention supplement. People in the study took 200 mcg of selenium daily to see if their skin cancer rate would drop. It didn't-but their rates of colorectal, lung, and prostate cancer went down sharply.
Selenium may also help protect you against heart disease. It also helps your immune system work effectively and helps remove heavy metals such as lead from your body. Vitamin E works better and longer in your body when you have plenty of selenium. All that makes selenium pretty important for a mineral you need only in micrograms.
Animal foods such as organ meats, seafood, lean meat, and chicken are all good sources of selenium. Whole grains such as oatmeal and brown rice are good plant sources of selenium, especially if they were grown in selenium-rich soil.
The benefits of selenium for cancer prevention and other health problems seem to kick in only at 200 mcg a day, though, so you may want to consider supplements. Selenium supplements come in two forms. Yeast-based supplements are made from yeast grown in a selenium-enriched medium.
"Organic" selenium is bound to an amino acid in the form of selenomethionine. Avoid inorganic forms of this mineral such as sodium selenite or selenate-you don't absorb them very well. You need to be very cautious with selenium supplements. In amounts greater than 600 mcg a day, selenium can be toxic, although 200 mcg a day seems to be quite safe.

Copper is involved in a lot of body processes, but its main functions are to help keep your heart and blood vessels healthy. You need copper to make an enzyme that keeps your arteries flexible-if you don't get enough, they could rupture. You also need copper to make the insulating sheath that covers your nerves. Copper works with iron to keep your red blood cells healthy. It's also very important for making the natural antioxidant superoxide dismutase (SOD).
There's no RDA for copper, but you can check out the Safe and Adequate range in the chart. The average American diet gives you anywhere from 0.8 to 3.0 mg of copper every day.
Hardly anyone is ever deficient in copper. There are some very rare inherited conditions such as Wilson's disease that make you store too much copper in your body, but on the whole, copper toxicity is also rare. You'd have to take in more than 10 mg a day to have any symptoms. The most common symptoms of copper overdose are nausea and vomiting.
Copper is found in a lot of common foods. There's over 2 mg of copper in a single oyster; other shellfish, such as lobster, are also good sources. Other good foods for copper include nuts, avocados, potatoes, organ meats, whole grains, and beans and peas. You may also be getting some from your drinking water if it goes through copper pipes. Copper is also found in most good daily multi supplements.
It's important to keep your zinc and copper levels in balance, because the two minerals compete with each other to be absorbed into your body. Most nutritionists recommend a ratio of ten parts zinc to one part copper. In other words, if you're taking 30 mg of zinc, be sure to take 3 mg of copper as well-but don't take more than that.

Here's a trace mineral we know you don't need. Even so, fluoride is very valuable for preventing tooth decay and even repairing decay in its earliest stages. Fluoridated drinking water reduces cavities in children by 20 to 40 percent and in adults by 15 to 35 percent-and the effect is even greater if you also use fluoridated toothpaste.
Fluoride helps build strong bones and keep them that way. There's some solid evidence that people who live in areas with fluoridated water have less osteoporosis. New drugs that combine calcium and fluoride for treating osteoporosis are now being investigated and show a lot of promise.
There's no RDA for fluoride, but today about 60 percent of the municipalities in the United States add it to their water supplies at the rate of one milligram per liter (which is another way of saying one part per million). That amount means the average adult will get between 1.5 and 4.0 mg a day just from drinking tap water.
The main reason water is fluoridated is that there really isn't any in food, with one exception: a cup of tea has about 0.3 mg. If you drink only bottled or filtered water or water from your own well, or if your community doesn't fluoridate its water, you and your family may not be getting the benefits of fluoride for your teeth and bones. Likewise, if you use "natural" toothpaste that doesn't have fluoride, you're not protecting your teeth fully.
There is no evidence at all that fluoride causes cancer, heart disease, kidney disease, Alzheimer's disease, or any other health problem.

Until 1972, when the first case came up, we didn't even know you could have a shortage of manganese. This mineral is still pretty mysterious. It seems to do a lot of the same things as magnesium, like help make your connective tissue, clot your blood, move glucose around your system, and digest your proteins. It may also be an antioxidant.
Most people take in anywhere between 2 and 9 mg of manganese a day. That seems to be enough, because manganese deficiency is extremely rare. There's no RDA, but we can tell you the Safe and Adequate range in the chart. Foods that are high in manganese include tea, raisins, pineapple, spinach, broccoli, oranges, nuts, blueberries, beans, and whole grains. Manganese can be very helpful for women with heavy menstrual flows. Eating more foods rich in manganese every day helps reduce the flow. Manganese is also an important mineral for building strong bones. If you don't get enough, you could be at greater risk for osteoporosis. Manganese also helps glucosamine to work better. The best way to get more manganese is to eat more foods that contain it. Many daily multi supplements also contain manganese. Don't overdo, though-too much manganese can interfere with your iron absorption.

All of your tissues contain tiny amounts of molybdenum. It's needed to make several enzymes, particularly one called xanthine oxidase. You need this enzyme to grow and develop normally and to use iron in your body properly. The average adult gets between 45 and 500 mcg of molybdenum a day from food. 45 mcg is a little less than ideal, but even so, molybdenum deficiency is almost impossible.
The amount of molybdenum in your food depends on where it was grown. The soil in some parts of the country is much higher in molybdenum than others. In general, good food sources include whole grains, lean meat, organ meats, beans, dark-green leafy vegetables, and milk. Most people get plenty from their food and don't need extra, although molybdenum is often found in daily multi supplements.

Did you know your body contains very tiny amounts of gold and silver? It does, but we have no idea why or what-if anything-would happen if you didn't have them. We do know why you have some other important trace minerals, though, so we'll run down the list and tell you the basics for each one.
*Boron. In the mid-1980s, researchers discovered that you need small amounts of boron to help you absorb calcium into your bones and keep it there. How much boron is still up in the air. There's no RDA or SAI yet, but many nutritionists today suggest getting 3 mg a day. That's not a problem, because most people get 2 to 5 mg a day from their food. Good dietary sources of boron are fruits, especially apples, pears, peaches, grapes, dates, and raisins. Nuts and beans are also high in boron.
*Cobalt. Remember the chapter on cobalamin (Vitamin B12)? You need cobalt to make this vitamin, which is essential for making red blood cells. In fact, that's all you need cobalt for. And because you don't need much cobalamin, you don't need much cobalt-a few micrograms is ample. If you're getting enough cobalamin from your food or supplements, you're getting plenty of cobalt.
*Nickel. We still don't know what nickel is doing there in your body, although it's probably involved with making some enzymes, hormones, and cell membranes. Too much nickel is associated with cancer, heart disease, and skin problems, but there's no known effects of too little nickel. Because you absorb very, very little nickel from your food, getting too much is almost impossible. Good food sources of nickel include chocolate, whole grains, nuts, beans, fruits, and vegetables.
*Silicon. You need silicon to make your bones, cartilage, and connective tissue. Nobody's ever been deficient in silicon because it's found in many foods, especially seafood, whole grains, root vegetables such as potatoes, and beans. Silicon supplements made from the plant horsetail are said to help your nails, hair, bones, and even arteries. Skip them-they're worthless.
*Tin. You've got this in your body, but we don't know what it does. This is one trace mineral you definitely don't have to think about.
*Vanadium. Recently a lot of vanadium products have come on the market, along with a lot of hype. Some of the ads even claim it "cures" diabetes. Don't believe it. Any possible benefit vanadium might have on your blood sugar is outweighed by its possible dangers even in
moderate doses. There's no known need for vanadium in your body.

There are some minerals that are OK in trace amounts but definitely not OK beyond that. Here's the rundown:
* Aluminum. Too much aluminum can cause nerve and brain damage. The average person doesn't need to worry much about this, but if you're a heavy user of aluminum-based antacids you could have a problem.
* Arsenic. Believe or not, you actually need this in very, very small amounts. Most people get about 140 mcg a day from their food. Doses larger than 250 mcg a day are toxic.
* Cadmium. Your body doesn't have any known use for cadmium, so it's never developed a way to get rid of it. Unfortunately, cadmium is found in cigarette smoke and air pollution, so you could accumulate a toxic amount over many years. If you don't already have enough good reasons to stop smoking, cadmium is another.
* Lead. This stuff is really bad for you, even though your body normally has a tiny amount of it. Even small amounts of extra lead can cause nerve damage, anemia, mental impairment, and muscle weakness. Recent research also ties lead exposure to high blood pressure. Most cases of lead poisoning occur from exposure to lead-based paint and air pollution. Young children are especially at risk.
* Mercury. This is another mineral that you have naturally in very small amounts. In larger amounts, though, it can do real damage and should be avoided. Mercury is used in a lot of industrial processes, so it can end up in air and water pollution. Fish such as tuna and swordfish that swim in mercury-contaminated water and eat smaller fish also contaminated with mercury may accumulate high levels of it. If you then eat the fish, you'll also get the mercury that's in it. Experts suggest eating these fish no more than once a week-less if you're pregnant or breastfeeding. What about the mercury in your silver dental fillings? We're not sure if this is really dangerous or not-talk to your dentist.
How can you avoid all these dangerous minerals? To a degree, you can't in our industrial society. There are some simple steps you can take, though: have lead paint removed, stop smoking, and avoid contaminated food, water, and air.