Worst Pills, Best Pills

An expert, independent second opinion on more than 1,800 prescription drugs, over-the-counter medications, and supplements


November 10, 2004

The Dietary and Herbal Supplements section of this web site contains information on the 13 biggest-selling dietary supplements, such as ginseng, St. John’s wort, gingko biloba, and 10 others, all derived from botanical (herbal) preparations except for chondroitin sulfate/glucosamine and Coenzyme Q10, which are of animal origin.

This section, however, is limited to those supplements that are vitamins or minerals and covers the same products, with important updates, discussed in the earlier...

The Dietary and Herbal Supplements section of this web site contains information on the 13 biggest-selling dietary supplements, such as ginseng, St. John’s wort, gingko biloba, and 10 others, all derived from botanical (herbal) preparations except for chondroitin sulfate/glucosamine and Coenzyme Q10, which are of animal origin.

This section, however, is limited to those supplements that are vitamins or minerals and covers the same products, with important updates, discussed in the earlier editions of this book.

Based on data from 2002, the most recent year for which such data are available, there were $7.7 billion in sales of vitamin and mineral supplements,[1],[2] projected to increase to $8.4 billion by 2005. The biggest-selling products were multiple vitamins, calcium, B vitamins, vitamin E, and vitamin C, these products alone accounting for 76% of total vitamin and mineral sales in 2002.

The section greatly benefits from a recent government-sponsored exhaustive review in the UK, Safe Upper Levels for Vitamins and Minerals, concerning safety issues related to these vitamins and minerals, both in dietary intake and in the form of supplements.[3] The report tackles the most frequently heard complaint about rigorously examining the safety of vitamins and minerals: “It has been argued that since vitamins and minerals are essential for human health, it is not appropriate to assess them in the same way in which other chemicals added to food are assessed. However, since there is much evidence that excessive intakes of some vitamins and minerals can cause harm, it is not appropriate to exclude essential nutrients from the safety assessment that is applied to other chemical substances [such as food additives] which are added to foods.”

In a number of the profiles on specific vitamins and minerals, information from this report is quoted directly.

One promotional strategy of supplement suppliers is to make people worry about whether they are getting enough nutrients. But do most people really need to take vitamins and minerals to supplement their diets? Or are they a waste of money? Are there better alternatives to taking supplements to ensure adequate nutrition? This section will attempt to answer these questions and help you sort through the fact and fiction surrounding nutritional supplements.

Causes of Vitamin and Mineral Deficiencies

It is a fact that some people do have vitamin and mineral deficiencies, usually older adults. They fall into three categories:

  1. People who do not eat enough food—fewer than 1,500 calories a day.
  2. People who eat enough food but have an unbalanced, low-quality diet, often deficient in fruits and vegetables.
  3. People who have medical problems or take drugs that contribute to vitamin and mineral deficiencies.

Too Few Calories

The most common cause of inadequate nutrition is eating too few calories. A diet that provides less than 1,500 calories a day does not ensure an adequate intake of all necessary nutrients. This can occur at all ages but is a particular problem in older adults. There are special reasons why this can happen.

Physical changes occur with aging. A decrease in the sensitivity of smell and taste results in food not tasting as good, and a subsequent loss of appetite. Dental problems may make eating more difficult, especially raw vegetables and meat. Physical handicaps can hinder food preparation and eating.

Economic factors also play a role in preventing people from eating enough. One out of every six older adults lives in poverty, which makes buying sufficient, wholesome food a difficult task.

An Unbalanced, Low-Quality Diet

Another group of adults at risk for vitamin and mineral deficiencies are those who eat enough food to feel full but eat an inadequate supply of necessary nutrients (vitamins and minerals that ensure your body’s good health). Certain changes make a deficiency more likely to happen.

As a person ages, his or her daily requirement for calories decreases because of a reduction in basal metabolic rate and physical activity. In order to maintain a weight of 140 pounds, a 70-year-old must eat fewer calories than he or she did as a 40-year-old. The basal metabolic rate, which determines how many calories your body burns off while resting, can decrease as much as 15 to 20% between the ages of 30 and 75. As a result, older adults require fewer calories. Less exercise results in a loss of lean body weight with a decrease in muscle and an increase in fat.

Regular exercise is the only way to slow down or reverse this age-related process. Exercise can increase both your basal metabolic rate and the amount of muscle in your body. It can also quicken the rate at which your food is digested and used. These effects from exercise allow you to eat more food without gaining weight.

Although the number of calories needed decreases with age, nutrient needs remain about the same (unless there is a special situation, such as a physical condition or a drug, that creates a need for more). As a result, a high-quality diet becomes more essential.

One obstacle to this goal of adequate nutrition and high-quality diet is that older adults often do not shop for or prepare their own food. Eating out often makes it harder to choose a healthy diet. Being immobile or in long-term institutional care reduces control over dietary choices. Living alone is also a barrier because preparing meals for one and eating alone is not always that appealing.

Medical Problems and Drugs

Vitamin and mineral deficiencies can also be caused by medical problems, including alcohol dependence and drugs. For example, diseases of the intestine, pancreas, and liver cause decreased absorption of certain nutrients, and some chronic diseases reduce the appetite.

Certain prescription and nonprescription drugs and alcohol also cause increased requirements of certain nutrients. These are the most common drugs (see the individual drug listings for more details):

  • drugs that affect the stomach or intestines, such as mineral oil and laxatives
  • cholesterol-reducing drugs, such as clofibrate and cholestyramine
  • antibiotics such as the cephalosporins and isoniazid
  • cytotoxic drugs (drugs that cause damage to cells), such as methotrexate, colchicine, and many anticancer drugs
  • anticonvulsants such as phenytoin and phenobarbital
  • blood pressure drugs, such as hydrochlorothiazide, hydralazine, and furosemide
  • alcohol

If you have any medical problems or use any drugs that increase the demand for certain vitamins and minerals, talk to your doctor about the best ways to increase your nutrient intake.

How to Prevent and Treat a Vitamin or Mineral Deficiency

Should people who have vitamin or mineral deficiencies take vitamin or mineral supplements? There is no simple answer to this question because of the various causes of such deficiencies. Sometimes, taking a supplement will help. But supplements are never the complete answer to anyone’s nutritional problems. It is far better to address the situation that could cause the deficiency and adjust the diet than to take a supplement and do nothing more.

Steps Toward a Better Diet

Eating a well-balanced diet with plenty of variety and high-quality food is the most important way to ensure good nutrition. Here are some healthy suggestions for doing that. If you decide to make changes in your diet, make them one at a time; you will have a better chance of succeeding.

1. Decrease the amount of fat in your diet, particularly saturated fats. Most Americans eat too much fat, which contributes to heart disease, the nation’s number one killer. Fat should contribute only 30% of your total daily caloric intake. You can decrease the amount of fat by:
a. trimming fat off meat
b. eating more fish and chicken (without the skin) instead of red meat
c. drinking skim milk instead of whole milk and cutting down on your consumption of whole-milk dairy products
d. eating fewer fried foods
e. steaming or baking food instead of cooking with oils and butter

2. Decrease the amount of salt in your diet. Eating a high-salt diet contributes to high blood pressure, thereby increasing your risk of heart disease and stroke. Foods that are high in salt include processed food, condiments, and salted meats. It is possible to buy low-salt crackers, no-salt pretzels, unsalted nuts, and low-sodium canned goods and breakfast cereals.

3. Eat more fruits, vegetables, and whole grains. These are the best sources of complex carbohydrates (starches that provide fiber and essential nutrients) and are also good sources of vitamins and minerals. Carbohydrates should contribute 55% of your total daily caloric intake, with the majority of them being fruits, vegetables, and whole grains. They also provide the best source of natural fiber, which comes from nonprocessed foods that are often more difficult to chew—raw cauliflower, broccoli, carrots, and whole-grain breads, for example. Fiber also promotes regularity (see psyllium (METAMUCIL, PERDIEM)) and may help to significantly reduce your cholesterol level and/or blood pressure.[4]

4. Decrease the amount of simple sugars in your diet. Replace foods sweetened with refined sugar (sucrose), such as candy, ice cream, pastry, and jam, with naturally sweet foods, such as oranges and apples.

5. Decrease your alcohol intake. Drink no more than three to five alcoholic drinks a week, if not fewer.

6. Increase your fluid intake to six to eight glasses of fluids a day, especially water. Kidney function is often reduced in older adults. Drinking more fluids helps the kidneys function better and also promotes regularity. However, first ask your doctor if you need to restrict your fluid intake.

7. Eat a wide variety of foods. A wide variety of wholesome foods will provide all the nutrients you need. It’s not too late to try new foods and get into new habits if your diet has been limited. Change your eating habits a little bit at a time and soon you will notice a difference. If you want to change your diet to get more of a specific nutrient, there is a list of good dietary sources of the individual vitamins and minerals at the end of this section.

Who Needs Vitamin and Mineral Supplements?

Having said that eating good food is the best and only sure way to improve your nutritional health, it should be added that for particular groups of older adults, taking vitamin and mineral supplements may be entirely reasonable and, at times, necessary:

1. People who eat fewer than 1,500 calories a day.

2. People who are institutionalized.

3. People with certain chronic diseases, including alcoholism, as well as liver, kidney, and intestinal diseases.

4. People who take drugs that interfere with absorption of or increase the excretion of nutrients.

5. People with a specific diagnosed nutritional deficiency or those who are in a high-risk group for developing a deficiency. For example, postmenopausal women should take calcium to prevent osteoporosis and strict vegetarians who do not eat eggs or milk products should take vitamin B12.

People who fit into these categories may require either a supplement of a specific nutrient or a multivitamin supplement with or without minerals. Either way, supplementation should be started only after discussion with and approval by your doctor and consideration of a dietary solution to the problem.

Taking Vitamin and Mineral Supplements as “Insurance”

What about people who do not fall into these categories? For example, what if you eat an inadequate diet and find it hard to make changes toward a healthy diet? Many people in this situation take a vitamin and mineral supplement to provide adequate “insurance” for their diets. Is this a good idea? One needs to look at both sides of the issue. Supplements cannot provide “insurance” from a poor diet because vitamin and mineral deficiencies are not the only problems resulting from eating an unbalanced diet and may not even be the most important ones.

A diet high in fat, cholesterol, and salt, for example, contributes to heart disease. A diet low in fiber causes constipation and irregularity of bowel movements and contributes to development of diverticulitis, a disease of the intestine that can result in bleeding of the intestine. A vitamin and mineral supplement will not insure against any of these problems. Only changes in your diet can help you to prevent such diseases. Relying on supplements for insurance can give you a false sense of security about your diet. We all have met people who eat a poor diet and justify it by saying, “Well, at least I’m taking vitamins.” This false sense of security may remove any incentive to improve diet.

What if you want to take a supplement anyway? There is no strong medical evidence of benefit from supplements when a specific deficiency does not exist, although it is a fact that people take them for peace of mind.

On the other hand, there is no evidence that a regular multivitamin supplement, with or without minerals, taken in a dose less than or equal to the recommended dietary allowance (RDA) is detrimental to your health. This does not hold true, however, for doses that far exceed the RDA (megadoses) of vitamins and minerals. If you decide to use a supplement, there are a few things that you should know.

Guidelines for Selecting Vitamin and Mineral Supplements

Be rational about selecting a supplement. If you are not at risk for a specific vitamin or mineral deficiency, choose a basic multivitamin plus mineral supplement. Taking specific pills for specific vitamins is a marketing tactic designed to make supplements more expensive. The average multivitamin pill with close to 100% of the RDA of each of the vitamins is less expensive.

Read the mineral contents on the label if you are concerned about increasing your intake of minerals. Most multivitamin supplements with minerals contain close to 100% of the RDA for vitamins but not for minerals. Mineral deficiency is actually more common than vitamin deficiency, despite what advertising might say. In older postmenopausal women, for example, calcium deficiency is a major health problem. We concur with the National Institutes of Health’s recommendation of 1,000 to 1,500 milligrams of calcium a day. If you cannot get this amount through your diet, take a calcium supplement, either alone or in combination with a vitamin supplement.

Do not buy a supplement that contains nutrients for which there are no known requirements or “new” vitamins, such as lecithin, carnitine, and inositol. Supporters of these supplements argue that we do not know all of what the human body really needs. Within the last 15 years, however, people with intestinal problems have been living successfully on injected solutions of protein, carbohydrates, fats, and established vitamins. If there were any unknown nutrients needed, this information would be known by now.

Buy the least expensive supplements. Many products are horrendously overpriced, being marked up to 1,000% over cost! Money that you overspend on supplements is money taken away from buying wholesome food. There is no benefit to be gained from a “natural”supplement versus a synthetic supplement. Brand-name vitamins are no better than generic versions. Buy the generics, which will work exactly the same as the more expensive name brands.

Recommended Dietary Allowances (RDA)—What They Really Mean

There is no need to take vitamin or mineral doses above the recommended dietary allowances. The National Academy of Sciences is the organization that sets the recommended dietary allowance (RDA) for each vitamin and mineral, and this allowance varies for males, females, and different age groups. Because they are designed to account for differences between older and younger adults, the RDAs are the most appropriate ones for an older adult to use.

There is a prevailing myth that the RDA is no more than the amount of a vitamin or mineral that is needed to prevent deficiencies. This is not the case. When an RDA is set, the committee first decides how much of a vitamin or mineral the average person needs, and then raises this number to cover the needs of 98% of the healthy population. This number is set at a level that is often two to three times higher than people’s needs, resulting in a significant safety margin—the government’s own “insurance” for your health.

Because of this built-in safety margin, the vast majority of people do not even need to get 100% of the RDA, as it is defined by the RDA committee. Thus, there is no need to take vitamin or mineral supplements that go beyond the RDA.

You may be familiar with two other guidelines, the U.S. recommended daily allowance (USRDA) and the minimum daily requirement (MDR). Neither of these guidelines is as appropriate as the RDA, especially for older adults. The Food and Drug Administration sets a single USRDA, which is largely based on the RDA for teenage boys. This allowance is not appropriate for older adults, since it does not account for age differences. Most vitamin supplements will state on the label what percent of the USRDA they provide. The MDR was a forerunner of the USRDA and is now out of date.



Folic Acid (folate)

Dried beans and nuts,* fruits, green leafy vegetables, organ meats,* whole grains, yeast


Beef liver,* carrots, sweet potatoes, tomatoes, green leafy vegetables, broccoli, watermelon, cantaloupe, apricots, peaches, butter,* margarine,* whole milk,* fortified skim milk

B1 (thiamine)

Dried Beans, peas, whole-grain or enriched breads and cereals, enriched or brown rice, enriched pasta, noodles, and other flour products, potatoes, pork,* beef liver,* nuts*

B2 (riboflavin)

Milk,* enriched and whole-grain products, green leafy vegetables, meat,* fish, poultry,* eggs,*

B3 (niacin)

Beans, peas, potatoes, enriched grain products, beef,* poultry,* pork,* liver,* nuts*

B6 (pyridoxidine)

Wheat and corn products, soybeans, lima beans, yeast, beef,* poultry,* pork,* organ meats*

B12 (cyanocobalamin)

Shellfish,* tongue,* fish, milk,* eggs,* cheese,* peas, beans, lentils, tofu, nuts,* beef,* poultry,*pork,* organ meats*


Citrus fruits (oranges, grapefruit, lemons, limes), tomatoes, strawberries, cantaloupe, cabbage, broccoli, cauliflower, potatoes, raw peppers


Some fatty fishes* and fish-liver oils,* vitamin D–fortified milk* and bread, eggs,* chicken livers*


Vegetable oils* (corn, cottonseed, soybean, safflower), wheat germ, whole-grain cereals, egg yolk*


Green leafy vegetables, beef,* pork*



Milk,* cheese,* yogurt,* ice cream*—low-fat and nonfat dairy products can be used—canned salmon and sardines, shellfish,* broccoli, green leafy vegetables, including collards, bok choy, mustard, and turnip greens


Organ meats,* red meat,* fish, green leafy vegetables, peas, wheat germ, brewer’s yeast, oysters,* dried beans and fruits

* High in fat and/or cholesterol. Keep servings of these foods to a minimum. Ideally, the calories in all of these foods together should be less than 30% of your diet.

The Myth of Megadose

There is a great deal of advertising that promotes the unproven benefits of taking “megadoses” of vitamins and minerals—supplements well beyond the RDA. Sensational claims of health and well-being are made for megadoses—they will “add vitality to your health,” “restore the luster to your skin,” and “perk up your sex life.” When looked at critically, these claims just don’t stand up. You will see, throughout the profiles in this chapter on specific vitamins and minerals, the results of carefully conducted studies that find practically all of the claimed benefits for megadoses are not valid.

To understand what vitamins or minerals can or cannot do, one must first understand their function in the human body. For the most part, a vitamin is a part of an enzyme (protein) that helps the enzyme perform certain chemical functions in the body. For example, many B vitamins help enzymes convert food into energy. Minerals act similarly. Calcium builds bones and also helps enzymes perform their functions. Iron is an essential element of red blood cells and helps them carry oxygen from the lungs to the tissues.

Vitamin functions were originally determined through vitamin deficiency diseases in people who were deprived of certain kinds of food for long periods of time. For instance, sailors often developed scurvy, a disease with such symptoms as bleeding into joints, poor healing of wounds, and emotional changes. It was determined that scurvy resulted from vitamin C deficiency when it was discovered that the sailors’ symptoms dramatically disappeared once they ate citrus fruits.

The vitamin manufacturers take the process of deficiency diseases and vitamins one step further. For example, claims are made that vitamin C will help cure skin or emotional problems, colds, or cancer. The overwhelming majority of these problems are not caused by vitamin C deficiency, so they will not improve in the average person taking vitamin C.

The flaw in this logic can be demonstrated by substituting “food” for “vitamin” in an example of a deficiency. If you fast for a long time, you will begin to develop certain symptoms, such as muscle aches, headaches, nausea, and dizziness. These symptoms of “food” deficiency will disappear dramatically once you begin to eat again. It does not follow from this that if you have symptoms of nausea, headaches, and dizziness while eating normally, more food will cause them to go away. But this is the kind of logic most manufacturers use to make claims for the benefits of megadoses of supplements: if some is good, then more must be better, and much more must be much better.

The only way to determine a beneficial effect of a supplement is through controlled scientific experiments, in which a supplement’s effects are compared with those of a placebo (dummy medication). No extravagant claims made by manufacturers for megadoses of any vitamins have stood up to these tests.

There are a few instances where vitamins have been determined to have specific additional benefits that have been demonstrated by rigorous scientific studies. Most of these therapeutic uses occur at doses not much greater than the RDA. They are discussed in the individual profiles that follow this section.

In addition to a lack of effectiveness, there are serious dangers associated with taking megadoses of many vitamins. People who take a multivitamin supplement in low doses have few risks; however, people who take high doses of certain vitamins have a risk of developing serious medical problems. Dangerous, toxic, and occasionally fatal effects have been associated with high doses of the fat-soluble vitamins A, D, E, and K. Even the water-soluble vitamin C and the B vitamins, which normally pass out of the body in your urine, can have adverse effects at high doses. Vitamin B6 has been associated with nerve damage,[5] for example. Too much vitamin C can cause stomach cramps or diarrhea.

Some vitamins should not be taken—even in normal doses—if you use certain drugs or have certain medical problems. If you use warfarin (COUMADIN) to prevent blood clots, you should not take vitamin K; it will inhibit warfarin’s ability to work. If you are B12 deficient and take folic acid (folate) without taking B12 as well, neurological symptoms can be worsened. If you are going to take any type of supplement, be sure to discuss it with your doctor before you start.

Vitamin and mineral supplements are a booming business in this country. Many people are misled by advertising into thinking that taking a supplement will help get rid of many of their health problems. But this is not the case. The most important step that you can take to maintain your nutritional well-being is to eat a healthy and well-balanced diet.

Certain older adults may need specific vitamin and mineral supplementation and should talk to their doctors about this. If you do not fall into one of these categories and still wish to take a supplement, you should follow a few rules of thumb.

First, realize that supplements are by no means the complete answer to good nutrition. Taking a supplement is not an adequate replacement for eating healthy food. If you do buy supplements there is no need to buy anything more than a regular multivitamin or a mineral supplement. Take supplements less than or equal to the recommended dietary allowance for older adults. Try to buy the generic brands, not the expensive name brands and “natural” supplements. Finally, avoid megadoses of any supplement. They will give you no additional benefits from the supplement but will greatly increase your chances of toxic adverse effects.







A (Retinol)

900 mcg or 2,970 i.u.

700 mcg or 2,310 i.u.


400 i.u.

600 i.u.


15 mg

15 mg


90 mg

75 mg

Thiamine (B1)

1.2 mg

1.1 mg

Riboflavin (B2)

1.3 mg

1.1 mg

Niacin (B3)

16 mg

14 mg

Pyridoxine (B6)

1.7 mg

1.5 mg

Cyanocobalamin (B12)

2.4 mcg

2.4 mcg

Folic Acid (folate)

400 mcg

400 mcg





1,200 mg

1,200 mg


700 mg

700 mg


420 mg

320 mg


8 mg

8 mg


11 mg

8 mg


150 mcg

150 mcg

i.u. = international units

mcg = micrograms

mg = milligrams

* From DRI (dietary reference intake) charts taken from the National Academy of Sciences Web site (http://ww.nas.edu). All intakes are the new recommended daily allowances (RDA) except for those with double asterisks (**), which are Adequate Intakes (AI).