We are in the midst of a nutritional explosion. Information about vitamins, minerals, and other nutrients is being thrust at us everyday. We are told that this vitamin cures this ailment and that food is bad for us. It’s so confusing and frustrating you don’t know what to believe.
You’re not alone. While our nutritional knowledge is expanding all the time, we still have much to learn. It is even difficult for doctors and nutritionists to keep up and sort out what’s what. However, there are a few basic facts about vitamins and minerals you should know in order to help you decide when, how, and why to use them.
What are Vitamins and Minerals
Scientists have known that vitamins are vital to life since the days of ancient Egypt. We only need small amounts of these “accessory food factors” for survival, but without them we become very sick or die. Vitamins play a number of roles in the body ranging from
metabolism to converting food into energy.
Although vitamins are each different substances chemically speaking, most of them must come from our food. Some can be formed from other compounds. For example vitamin A can be made from beta-carotene. Others are partly manufactured by the body. Friendly
microorganisms that live in the gut help make vitamins K, B12, thiamin, and folic acid. Our skin uses sunshine to create vitamin D.
Unlike vitamins, minerals make up a much larger portion of the body–up to five percent. There are two classifications of minerals required for health: the macronutrient elements and the trace elements. The trace minerals such as arsenic, chromium, copper, and tin are needed in minute quantities, but are still essential for survival.
Recommended Daily Allowances
The best way to get your vitamins and minerals is through food. Taking nutrients in pill form, while often necessary, is not ideal. There is undoubtedly a balance between nutrients in whole, fresh, organically grown foods that is difficult to replicate. Not only are we still dissecting how and what nutrients comprise our diet, but when man tries to imitate nature the results usually fall short. For instance, breast milk with its mysterious nutritional mixture is
still infinitely better for a baby than infant formula.
The Recommended Daily Allowances (RDAs) were created as a guideline to vitamin and mineral requirements. First presented 50 years ago, the RDAs have provided ongoing information based on current scientific data. Understanding and research have, of course,
changed over the years. Even today incomplete information and varying expert opinions create disagreements as to exact nutrient levels. RDA experts acknowledge that incomplete data makes it impossible for them to set RDAs for all vitamins and minerals.
In order to simplify their charts, the RDA subcommittee say their information is intended for healthy people. Each RDA is meant to be an average figure that is safe and adequate. These numbers obviously don’t fit everyone. Although RDA values are given for different age groups and sex, only one body size is used per category. For instance, women 25 to 50 years old are assumed to be five foot four inches and 138 pounds–the average weight and height for women in this age group.
In reality each of us is not only a different size, but we have different nutrient needs. Sex, age, where we live, as well as our diet, health, physical activity, biochemical individuality, and ability to absorb food elements all determine how much vitamins and minerals we require. It is these factors that make RDA charts so difficult to compose. Your individuality is also what dictates whether you need vitamin and mineral supplements (1).
Should We Take Supplements
Modern society is fraught with nutritional bandits. Stress from noise, pollution, overcrowding, and daily demands rob us of vital nutrients. Today’s soil is suffering from its own nutrient deficiencies due to modern farming practices. Processing and refining
strip whole foods. Water, additives, sugar, and fats are used to prop up depleted foods. If this weren’t enough, storing and cooking foods withdraws more nutritional value.
These conditions have left many of us with higher-than-RDA requirements. Unfortunately, much of our food supply is not up to the job of providing what we need. The first step is to eat and live well. Step number two is to take a balanced vitamin and mineral supplement if needed.
Dietary supplements are also useful as medicines. As the evidence grows, vitamins and minerals are being recommended for both the prevention and treatment of several illnesses. In order for nutrients to act therapeutically, however, relatively high dosages are needed. This is a case where supplements, not foods, are the answer.
Antioxidants are one group of vitamins and minerals that are establishing a niche in medical treatment. Selenium, copper, zinc, manganese, beta-carotene and the vitamins E, C, and A, known antioxidants, have displayed varying abilities to prevent or treat diseases particularly cancer (2).
There are situations where supplements should be taken cautiously. Pregnant or nursing mothers need to consult with their doctor before taking anything–including vitamins and minerals. When taken alone or in unbalanced formulas, certain vitamins and minerals can interfere with or exaggerate another nutrient’s absorption. Some drugs interact with nutrients. When very high doses of folate are taken, 15 mg or more, it may cause convulsions in epileptics taking phenytoin.
Nutritional supplements come in many forms. Pills are most familiar either as tablets or capsules. Powders and liquids are also available and prefered by those who have difficulty swallowing due to age, illness or an aversion to pills.
There’s more to a nutrient than its shape. In addition to vitamins and/or minerals, many supplements also contain additives. Fillers such as salt or sugars may be used to fill up space in a capsule. Corn starch or molasses might be binders that help keep a tablet intact. Disintegrators, corn and potato starch are most common, encourage a tablet to dissolve after you swallow it. Coloring and flavorings are also often used.
Supplements may be tainted with substances used during manufacturing. Magnesium stearate, hydrogenated oils, and talc are lubricants used so nutrient mixtures won’t stick to machines (3).
Unfortunately, nutritional manufacturers are not required by law to list everything in their products. You may have knowingly or unknowingly reacted to supplements in the past. If you are allergic to corn, then a corn starch binder may have been the culprit. Lactose
in supplements can cause nausea, bloating, and cramps in someone with lactose intolerance (4). Even the source from which a nutrient is derived can set off a reaction.
At the very least, many of these additives can diminish your absorption of a vitamin pill. If you can’t digest supplements, then your body can’t use them. Many people mistakenly believe that nutritional health care is second-rate because the vitamins and minerals they take don’t work. The problem may have been the quality of the supplement.
High quality, hypoallergenic supplements are available with a little research. If you are unhappy with one product, try another, write to supplement companies about what’s in their formula, or ask a trained nutrition-oriented practitioner.
Nutrients offer safe and effective treatment for many conditions. But don’t assume that the larger the dose, the better they are. All substances, even water, can be harmful at high enough
levels. Some vitamins and minerals cause acute poisoning taken in massive amounts. Lower, but still excessive, levels taken for weeks, months or even years may lead to chronic toxicity.
It is difficult to determine vitamin and mineral toxicity levels partly because it’s unethical to perform these kind of experiments on people. We usually rely on animal research while taking into account physiological and biochemical differences between us and the species
tested. (Many people consider it unethical to conduct studies on animals as well).
Occasionally information is collected when a population inadvertently consumes too much of a nutrient. For example, boron overdose was studied early in the century when sodium borate was a common food preservative (5). Although rare, individual cases of nutrient poisoning also appear in the medical literature. All of this data helps direct where toxicity levels should be set.
We also need to remember that nutrients come from a number of sources besides supplements and foods. Fluoride is added to our water, toothpaste, and is used in dental care. Vitamin D is provided mainly by sun exposure and is artificially added to milk. Iodine,
initially added to salt to prevent goiter, is now found in contaminated dairy products, breads and pastries, some artificial colorings, some produce, fish, and seaweed. There are now reports of excess iodine causing goiter in England, Wales, Central China, Australia, Japan, and the U.S. (6,7,8). So toxicity levels may be lower than expected if you are getting a particular nutrient from many sources.
Generally speaking, water soluble vitamins specifically the Bs and C are relatively nontoxic. The fat soluble vitamins including A, D, E and K have more defined levels of toxicity. There are, of course, exceptions. There have been no reported cases of toxicity using vitamin E. Whereas the odd case of problems with vitamin B6 has occurred. Side effects from too much B6 typically involve neurological symptoms such as tingling in the limbs and an unsteady gait (9).
When megadoses of vitamins and minerals are used nutrients begin to act in a pharmacological rather than a physiological manner. This type of prescribing is best left in the hands of health care experts. Also, don’t assume that every mineral and vitamin needs to be supplemented. Iron, although found in many multiple formulas, should only be supplemented where indicated such as iron deficiency anemia. Excess iron over a period of time may increase your risk of heart disease, cancer, SIDS, and diabetes (10).
The science and art of nutrition is complex. There are many factors to consider particularly when taking vitamins and minerals supplements. Be smart. Use the services of a well trained and credible nutritionist or other knowledgeable health care provider who can show you how to take nutrients safely and effectively.
- Subcommittee on the Tenth Edition of the RDAs, Food and Nutrition Board, Commission on Life Sciences, National Research Council. Recommended Dietary Allowances (10th ed). Washington, DC: National Academy Press, 1989.
- Diplock AT. Antioxidant nutrients and disease prevention: an overview. American Journal of Clinical Nutrition 1991;53: 189S-93S.
- Czap A. Is your polyplasdone kollidon with your solka-floc? Townsend Letter.
- Brandstetter RD, Conetta R, Glazer B. Lactose intolerance associated with Intal capsules (letter). The New England Journal of Medicine 1986;315(25): 1613-14.
- Nielsen FH. Facts and fallacies about boron. Nutrition Today 1992 May/June;27(3): 6-12.
- Pennington JAT. A review of iodine toxicity reports. Journal of the American Dietetic Association 1990;90: 1571-81.
- Mu L, et al. Endemic goitre in central China caused by excessive iodine intake. The Lancet 1987, August 1: 257-8.
- Barker DJP, Phillips DIW. Current incidence of thyroitoxicosis and past prevalence of goitre in 12 British towns. The Lancet 1984, September 8: 567-70.
- Dolphin et al (eds). ®)9¯Vitamin B6: Pyridoxal Phosphate.®):¯ Volume 10: John Wiley & Sons, 1986, pg 595.