This article appeared in the FEBRUARY 1998 issue of VITAMIN RETAILER MAGAZINE, Inc. - page(s) 34 - 36.

The use of nutritional supplements is fraught with danger - according to some conservative nutritionists and physicians. In reality, just the opposite is true.

The marjority of supplement users follow label directions and use supplements sensibly. Robert Reynolds, Ph.D., from the University of Illinois, quotes data from a national health survey that found "few, if any, individuals were consuming nutrients in amounts considered toxic."¹

In addition, the side effects that are caused by excessive vitamin or mineral intake are nearly always reversible upon the cessation of excessive intake. The few case reports of adverse reactions to supplements involve extremely high doses. This small number of cases confirms that the millions of supplement-taking Americans are using them safely and appropriately.

According to information from the National Capitol Poison Center, in the eight-year period from 1983 to 1990, one fatality resulted from vitamin supplement use (the vitamin involved was niacin). During that same period, however, 2,556 deaths resulted from the use of prescription and non-prescription drugs (not including intentional suicide or illegal drug use), such as blood pressure medications, sleeping pills, and asthma therapies. This comparison illustrates the relative safety of vitamin and mineral supplements.²

Although the risks associated with sensible use of supplements are very small, the benefits are not. Research has uncovered compelling evidence that optimal intake of micronutrients can bolster immune function, stave off premature aging, and reduce the risk of cancer, heart disease, and many other degenerative diseases. In fact, some researchers suggest that improved intake of several vitamins and minerals could cut health care costs in this country significantly. For example, if all women of child-bearing age took folic acid daily and individuals over the age of 50 supplemented with vitamin E each day, there would be an estimated $20 billion saved simply from avoidable hospitalizations due to birth defects and heart disease.^3-4

The hard and fast rules of nutrition used to state that all water-soluble vitamins are safe at any intake level (since excesses could be flushed out of the body) and all fat-soluble vitamins (since excesses could be stored) are toxic at intakes approximately 10 times above the Recommended Dietary Allowance (RDA). Current nutrition knowledge has revamped these vitamin and mineral toxicity guidelines.

Each nutrient should be evaluated individually to assess benefits and risks. For instance, excessive intake of the water-soluble vitamins niacin and vitamin B-6 are now known to produce adverse effects, while the fat-soluble vitamins beta-carotene and vitamin E are not associated with toxicity, even at very high doses.⁵

Although the majority of nutrients can be taken safely at levels far in excess of the RDAs -- leaving a margin of error for even over-enthusiastic supplement users -- certain nutritional supplements taken in excessive amounts can lead to serious side effects. Just as everyone should take the time and care to plan a balanced diet, so should these resources be used to carefully plan supplement choices

Getting It Right With Vitamins

Most people take vitamins as part of a multiple "one-per-day" type product. These multi-vitamin supplements are designed to provide a balanced mix of vitamins and are very safe to use. Occasionally, problems can arise when large amoounts of an individual vitamin is taken as a stand-alone supplement.⁶

As a general rule of thumb, the fat-soluble vitamins (vitamins A, D, E, and K) have more potential for toxicity than do the water-soluble vitamins (the B vitamins and vitamin C), and should therefore be used with more care. This is because the fat-soluble vitamins are stored in the fatty areas of the body, where they can build up to dangerous levels. Conversely, excess levels of the water-soluble vitamins are generally washed out of the body before they can cause harm.

Of the fat-soluble vitamins, vitamin A is of the greatest concern to women, since daily intakes above 10,000 I.U. by pregnant women over a prolonged period of time can increase the risk of birth defects. Other signs of too much vitamin A include vomiting, nausea, hair loss, and dry and cracked lips. Beta-carotene -- which the body converts to vitamin A -- is a safer choice. The primary problem occurring with beta-carotene is a harmless (and reversible) yellow coloring in the palms of the hands and soles of the feet at intakes above 60 mg. daily.⁷

Vitamin D can be toxic at just a few times its RDA (greater than 800 I.U. per day). Symptoms can include diarrhea, headache, and nausea.

Unlike the other fat-soluble vitamiins, vitamin E is relatively non-toxic, although very large doses can interfere with blood clotting in persons taking anticoagulant medications.

Large doses of the synthetic form of vitamin K can cause anemia; which is why supplements of this vitamin are only available through a prescription.

For the most part, the B vitamins are considered safe in a wide range of intakes. A form of niacin called nicotinic acid may cause a flushing sensation to the face, which is why "snake oils" often included this vitamin in their formulas, erroneously leading people to believe that the product was "working."

Vitamin B-6, when taken in amounts greater than 500 mg. daily over several years, can cause permanent nerve damage, characterized by a tingling sensation in the hands and feet.

Although folic acid (another B vitamin) is very safe -- and all women of childbearing age should consume at least 400 mcg. per day to lessen the risk of birth defects -- this vitamin can indirectly cause problems. If someone is deficient in vitamin B-12, the folic acid can mask some of the symptoms, allowing the deficiency to progress until permanent neurological damage has occurred. Simply taking a B-complex supplement, which includes all of the B vitamins, will circumvent this potential problem.

Vitamin C is exceedingly safe at a wide range of intakes, which is good news to the one-third of adults who already take this popular vitamin. Even mega-doses of vitamin C cause no problems for the vast majority of people. However, for some who are sensitive, taking as little as 1,000 mg. per day can trigger nausea and stomach cramps.⁸

Minding The Minerals

For many people (especially women), consuming enough minerals is a lifelong problem. For instance, 7.8 million women in the U.S. are estimated to be deficient in iron. Nevertheless, there are many problems that can arise from excessive intake of minerals. With iron, the most common side effect of increased intake is constipation, although there are rare reports linking high iron levels with an increased risk of heart disease, cancer, and susceptibility to infections.⁹

Too much magnesium is more likely to result from the overuse of magnesium-containing antacids or laxatives, rather than magnesium supplements. However, sensitive individuals may develop diarrhea after taking as little as 35--500 mg. of magnesium. Aside from imparting a "garlic" odor to the breath, taking more than 1,000 mg. of selenium daily can cause hair loss, skin rashes, and brittle fingernails.

Many people take zinc to boost immune function, but zinc can be too much of a good thing. Taking more than 150 mg. of zinc per day can have the opposite effect and actually interfere with immunity.¹⁰

As with vitamins, unless there is a specific health issue that necessitates higher levels of an individual mineral, it's probably best to balance mineral intake with a multi-mineral supplement.

News From The Hormone Front

Hormone supplements need to be taken along with a healthy dose of caution. DHEA (dihydroepiandrosterone) is a hormone produced by the adrenal glands and is now available as a supplement. This hormone can be converted to testosterone in the body, accounting for why DHEA can trigger facial hair and deeper voice in some women.

Recently, more serious side effects have been linked to the use of DHEA, namely heart irregularities (see this months ,a href="asktom-naturally.com/naturally/hormones.html">Q&A with Dr. Ray Sahelian). For this reason, the use of DHEA and pregnenolone should be limited to 5-10 mg. per day, and the hormones should not be used continuously.

Melatonin, the jet lag "antidote," helps the body's internal clock adjust to a new sleep schedule. As such, it can sometimes cause monor side effects such as undesired drowsiness, sleepwalking, and vivid dreaming.

Benefits Far Outweigh Risks

What's the bigger picture regarding supplement use? Looking at it from a risk-versus-benefit perspective, there's no doubt that dietary supplements confer more benefits than potential risks. And, as this article has asserted, the risks associated with nutritional supplements can be further minimized by limiting supplement intake to recommended levels.