Breaking Down Vitamins and Minerals
Some have letters for names. Some have tongue-twisting chemical names. No matter where you encounter vitamins and minerals -- in a drugstore, in a bottle, listed on the back of your cereal box -- you know you need them. But how much and which ones?Because there are so many, vitamins and minerals can be very confusing topics. However, just because they are confusing, doesn't mean you can ignore them. Vitamins and minerals are crucial to normal body functions and some of them may have a role in preventing our most deadly diseases such as cancer and heart disease, among other not-so-deadly ones.
 ©2006 Publications International, Ltd. Vitamin C is one of the few vitamins that most people know and know where to obtain it. |
More, Please
If you're consuming "suboptimal" amounts of a nutrient, it's not good. You're not deficient -- that is, you won't show disease symptoms -- but you're taking in less than is thought to be the best for good health. The consequences of this aren't always clear, but the impact of less-than-desirable levels may accumulate over time, possibly leading to chronic health problems.
Nutrients are sexist. It's a fact. Men and women require most nutrients in similar amounts -- men slightly more of some. Yet it's much easier for men to meet their needs, because they need and get more calories, on average, than women. And that means they get more nutrients, too. Women who are dieting have an even tougher time meeting nutrient needs, unless they take a supplement.
The following vitamins and minerals are ones that you may not be getting in adequate amounts. There are dietary solutions for most, but some nutrients are difficult to get in the average diet and may require supplementation.
Vitamin A. Do you eat your four or more servings of fruits and vegetables per day? If not, you're not alone. Surveys show that less than half of adult women meet the Dietary Reference Intake (DRI) for vitamin A, probably because they don't eat enough fruits and vegetables rich in beta-carotene -- a precursor of vitamin A. Suboptimal intake could weaken your immune system.
Riboflavin. You don't drink milk either? Meet your counterparts: Only one half of adult women meet the DRI for this vitamin. If you're included in this poor showing, it may be because you're not including enough dairy products and whole or enriched grains in your daily diet.
Vitamin B6. Again, it's women who are at greatest risk for not meeting their needs for this vitamin. The average intake is just over 50 percent of the DRI. Women on birth control pills seem to need more than average. Some men and seniors of both sexes may fall short, too. If you fit into any of these groups, your all-important immune system may suffer for it. In studies, supplements of vitamin B6 have been shown to boost immune function in seniors.
Vitamin B6 may do much more than simply keep your immune system up and running. Research has identified that vitamin B6 protects the body from a build-up of homocysteine in the blood. High homocysteine levels have been linked to an increased risk of heart disease.
Folate (folic acid). This is a red-flag nutrient if you're a woman taking birth control pills. Smokers and alcoholics may be low, too. All women trying to conceive should take a supplement, since a low intake can cause birth defects such as spina bifida in the first few weeks after conception. Even women not considering pregnancy might benefit from the protection folic acid seems to afford against a virus that can cause cervical cancer.
Men aren't left out in the cold either. Like vitamin B6, folate is necessary to break down homocysteine, an amino acid associated with increased risk of heart disease. Research on 15,000 physicians has revealed that those with diets suboptimal in folate and vitamin B6 were three times more likely to suffer heart attacks than those whose diets were adequate in the two nutrients.
Vitamin C. Such an easy-to-get nutrient shouldn't be in this category, but certain groups of people don't get enough, particularly those who skimp on vegetables and fruits. Smokers typically have low blood levels of vitamin C, because their needs are twice those of nonsmokers.
Calcium. The trend toward drinking soft drinks instead of milk with meals is having an effect. Less than a quarter of adult women and less than half of young children meet the DRI for calcium, which is 800 milligrams for children ages 4 to 8; 1,300 milligrams for children ages 9 to 18; 1,000 milligrams for adults ages 19 to 50; and 1,200 milligrams for adults over 50 years of age. Your doctor may advise you to get even more calcium each day. To get recommended levels, you may need to take calcium supplements.
Copper. No one is yet certain about the cost of ignoring this seldom-noticed mineral. Some studies have linked low copper levels to arthritis, high blood sugar, heart disease, and high cholesterol. If you're typical, you are not getting even close to the DRI for copper. And if you take megadoses of vitamin C (1,500 milligrams or more per day) you could be disrupting copper absorption and contributing to a copper insufficiency.
Chromium. Talk about a deficit. A government researcher who studied chromium in the diet estimated that 90 percent of Americans get less than the minimum daily recommendation for chromium. The value of chromium is in its blood sugar regulation. The rise in blood sugar that comes with aging may be a result of years of inadequate chromium in the diet, as chromium is needed for insulin to work.
The mineral chromium is essential to insulin functioning, and a high-sugar diet can, by stimulating insulin, actually hasten the body's depletion of chromium. Thus, less chromium is left for insulin to use--a classic catch-22. The proliferation of high-fructose corn syrup in foods, especially in soft drinks, is worrisome because it adds to our sugar load and presumably to our need for chromium. |
Iron. Remember those old Geritol ads? Well, forget them. They gave a generation the wrong impression that older women needed more iron. It's just the opposite. Women in their child-bearing years who are menstruating need iron.
Why? Because they lose iron in menstrual bloodflow, which puts them at risk for anemia. Less than one-fifth of menstruating women meet the DRI for iron. Children are also susceptible, especially toddlers, preschoolers, and adolescents who are growing rapidly and whose diets are typically lacking in iron. Athletes and vegans (strict vegetarians) should also be on the lookout.
Fatigue doesn't always signal anemia, and anemia isn't always due to an iron deficiency, so any suspicion should be checked out by your doctor, who can run the appropriate tests. To boost iron absorption, drink orange juice (or get vitamin C from another food source); vitamin C helps your body absorb iron from plant foods. Avoid drinking coffee or tea at mealtimes and never at the same time you take a supplement that contains iron.
Magnesium. Three out of four people do not meet the DRI for magnesium. This has implications for many growth and repair jobs in the body, but it can also contribute to osteoporosis. Calcium gives bones their strength; magnesium makes them elastic -- just as important for resisting breakage.
Zinc. If you're not a big meat eater you might be short on zinc, unless you happen to like oysters. Just six medium Eastern oysters will give you five to six times the DRI. Otherwise, you probably get only about half what's recommended.
You need zinc for hundreds of enzymes that trigger important reactions in the body. The lower levels of zinc that come with age may be one reason for an increase in infections in older people. Seniors given zinc supplements show improved immune response.
However, caution is in order here. Too much zinc can also impair the immune system as well as cause a copper deficiency and lower blood levels of the beneficial HDL cholesterol. If you take a multivitamin-mineral supplement, be sure it contains 15 to 30 milligrams of zinc. Avoid supplements with a megadose of zinc.
Vitamins Not To Overdo
Some vitamins can actually be harmful is you ingest too much. Here's a list of what to look out for:
Vitamin A. Don't make the mistake of substituting preformed vitamin A (called retinol) for beta-carotene in the hopes of preventing disease. Vitamin A is toxic in large amounts, over 50,000 international units (20,000 international units in children). Though toxicity usually results from oversupplementation, liver contains extremely high levels of vitamin A; eating too much too often is not a good idea.
Although vitamin A is vital to eyesight and immune function, too much vitamin A also causes vision problems and a weakened immune system that invites infection. If a pregnant woman takes too much, it can cause birth defects in the fetus.
This is not a nutrient to fool around with. Excess vitamin A can cause blurred vision, headaches, nausea, achy bones, or irritability. Particular caution for seniors: As you age, your liver is less able to remove vitamin A from the bloodstream, making toxicity a bigger worry. Supplements with preformed vitamin A should not contain more than the DRI. If you feel that you need a vitamin A supplement, it's best to take beta-carotene, which can be converted to vitamin A in the body.
Vitamin D. This is another nutrient that demands respect. Toxic levels are only five times the DRI. Children are particularly susceptible to a toxic reaction to vitamin D, which causes blood calcium levels to soar -- a dangerous condition.
Seniors often don't get enough vitamin D. They are not in the sun a lot, and when they are outside, their skin requires more time to convert vitamin D to its active form. Often, they don't drink much milk either. If this describes you, ask your doctor about taking a combination calcium-vitamin D supplement, or a multivitamin-mineral supplement. Just be sure you take only one of these options and that the amounts don't exceed 100 percent of the DRI.
Niacin. As its nicotinic acid alter ego, this B vitamin becomes powerful enough to lower high cholesterol levels. To do so, it must be prescribed in high doses (more than 1,000 milligrams), which can cause nicotinic acid flush -- an immediate redness and swelling of the face and neck, often accompanied by itching, headache, and nausea. This side effect lessens with use, but taking this supplement should be monitored by your doctor. Heartbeat abnormalities are more serious. People with diabetes are advised to stay away from high doses of nicotinic acid because it can raise blood sugar to dangerous levels.
Vitamin B6. This nutrient was once thought to be immune to toxicity. It took until the 1980s, when it became popular to take vitamin B6 supplements in ever larger amounts, to discover the upper limit of its safety. Here's what caused it to finally lose its cachet: nerve damage from doses as low as 500 milligrams a day, more commonly from amounts over 2,000 milligrams. Fortunately, the damage is reversible if the supplements are stopped at the first sign of tingly or numb extremities or trouble walking.
Iron. Like vitamin A, this Jekyll-and-Hyde nutrient is on both lists. Many people don't get enough, but too much can be dangerous, too. You hear a lot more about having iron-poor blood than you do about iron overload (or hemochromatosis), which can develop in people who inherit a gene that causes the body to absorb too much iron. This potentially fatal condition threatens a surprisingly large number of people -- 1 in every 250 -- mostly men and postmenopausal women, because their iron needs are lowest. They are best off avoiding supplements with iron.
Iron supplements also threaten children; they are the leading cause of accidental pediatric poisoning. It takes only five tablets of high-potency iron to kill a child under age six. Childproof caps are a must, though recent cases have been caused by caps left off or not tightened. Don't overlook grandparents' homes, where caution may be less vigilant and accidents more likely.
What symptoms there are show up late, including fatigue (which might be mistaken for iron deficiency), abdominal pain, achy joints, and a bronze skin tone. The only way to identify whether you have an impending problem is to get your blood levels of serum iron tested for total iron-binding capacity and percent transferrin saturation. If suspicious, serum ferritin is then checked as well. Because this is an inherited disease, anyone with an affected relative must be tested. The only treatment is frequent blood donation. |
If you haven't heard of antioxidants by now, you're just not paying attention. They're the hot topic in disease prevention. Antioxidants aren't new, however. They've been around all the time; we just weren't smart enough to appreciate them. Now we know they're like secret service nutrients that fight against a form of biological damage called oxidation -- a chemical reaction that occurs when oxygen latches onto substances that have left themselves exposed to attack.
With oxidation come the inevitable party crashers -- free radicals -- that do harm to whatever cells are in their way. This destruction escalates into chain reactions that eventually can even alter the genetic makeup of cells. Scientists now think free radicals are formed by pollution, cigarette smoke, even sunlight. It's been said that we have never needed antioxidant protection more than we do now.
In addition to their regular duty, several nutrients act as antioxidants. The best-known of these are vitamins C and E and beta-carotene (though beta-carotene's primary benefits may not stem from its antioxidant role). In addition, selenium and copper are essential components of enzymes needed for antioxidants. Other nutrients now being credited with antioxidant properties include riboflavin, magnesium, manganese, zinc, and another carotenoid called lycopene.
Research has shown that antioxidants are beneficial to health. They protect against chronic diseases like cancer and heart disease, and they also boost immune function and combat aging, which may simply be the body's response to repeated assaults by free radicals.
But there is still disagreement over just how important antioxidant supplements are. It is recommended to get antioxidant nutrients from foods, such as fruits and vegetables. Vitamin C appears to be a jack-of-all-trades, with links to lower rates of cancer, heart disease, and cataracts. Beta-carotene, on the other hand, has been riding a roller-coaster of evidence as to whether it protects against certain cancers and heart disease.
Despite mostly strong research results, particularly with lung cancer, some are skeptical of beta-carotene's role because most of the evidence came out of studies with fruits and vegetables, not simply beta-carotene supplements. It has become increasingly clear that other substances in fruits and vegetables may be just as important.
If you're not getting your necessary vitamins and minerals you might consider supplements, which will be discussed in the next section.
This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider
