What is it?

PHYS Update: On August 13, 1997, the Food and Nutrition Board issued the first in a series of DIETARY REFERENCE INTAKES (DRIs): multi-level recommendations that will update and eventually replace the old RDAs. The first report covered calcium, phosphorous, magnesium, vitamin D and FLUORIDE At least six more reports on other nutrients are expected to follow.

Why You Shouldn't Rely on the RDAs

Under the heading of Clinical Considerations, we are told that, "RDAs apply to healthy persons," and that the RDAs "do not cover special nutritional needs arising from metabolic disorders, chronic diseases, injuries, premature birth, and other medical conditions, and drug therapies (1,p.20)." As it turns out, the RDAs also do not apply to active people. Consider the following quote which appears under the heading of Strenuous Physical Activity (1,p.19):

"Increased activity increases the need for energy and some nutrients. Such needs usually are met by the larger quantities of food consumed by active people, provided foods are sensibly selected.

In hot environments, activity increases water and salt losses through sweating and, if prolonged, can also lead to measurable losses of other essential nutrients. Special attention should be given to the immediate need for water under such conditions."

It also appears that the RDAs do not apply to people who are "stressed out." In part, the stress response is characterized by an increase in the body's output of cortisol and adrenaline (2). It is known that both cortisol and adrenaline increase magnesium excretion from the body (3). In other words, the body's ability to absorb and utilize magnesium is compromised during periods of stress. In addition, "it is proposed that, in turn, magnesium deficiency promotes susceptibility to stress, creating a "vicious circle" that is further worsened by a tendency for stress to lead to alcohol abuse and greater magnesuria (3)." In simple English, evidence demonstrates that, "stress increases magnesium requirements (3)."

Although the requirements of other nutrients such as thiamin (B1), riboflavin (B2) and niacin (B3) are increased in response to stress (4), we focused on the relationship between magnesium because it is known that magnesium is required by over 200 enzymes and it is also needed whenever the body utilizes its energy molecule known as ATP (3). Magnesium deficiency can affect that body in many ways. For example, deficiency can lead to osteoporosis, heart disease, a reduction in exercise capacity (3,5), inflammation (5), fibromyalgia (6), and fatigue (7). All of these problems are very common among the US population, and it is very rare that supplementation with magnesium or other nutrients are considered.

In summary, the RDAs do not apply to people with metabolic disorders, chronic diseases, injuries, and other medical conditions, as well as those undergoing drug therapies, for people who exercise and those of us who are "stressed out." We must realize that physical injuries are very common and many of us currently suffer from pain, fatigue and depression, which are all considered to be medical conditions. Furthermore, many of us exercise and most of us are "stressed out." Based on this information, it is very reasonable to ask the following question: Who are the healthy people for whom the RDAs apply?
This is a very important question because we need to know what the RDA book means by the word "health." Remember, the RDA book states that, "RDAs apply to healthy persons (1,p.20)." Unfortunately, the RDA book never defines "health," and thus, it is not possible to determine if we are one of those for whom the RDAs apply.

According to an epidemiology text that quotes the World Health Organization (8), and a medical dictionary (9), the word health is defined in the following manner:

"A state of complete physical, mental and social well-being, and not merely the absence of disease and infirmity."

Based on this definition, it is safe to say that no one truly experiences a true state of health, for no one experiences complete physical, mental and social well-being. Thus, according to the accepted definition of health, the RDAs cannot apply to anyone. What good are the RDAs and why do we use them? Well, at best the serve as a guideline. If you are not taking in at least the RDAs, it is reasonable to suggest that you are placing your body at risk for developing a degenerative disease. Therefore, it is very important for you to find out if your diet contains less than the RDAs.

References

1. Recommended Dietary Allowances. 10th edition. Washington, DC: National Academy Press, 1989
2. Asterita M. The Physiology of Stress. New York: Human Sciences Press, 1985:43
3. Dreosti I. Magnesium status and health. Nutrition Review 1995;53(9):S23-S27
4. Williams S. Nutrition and Diet Therapy. 6t edition. St Louis: Times Mirror/Mosby College Publishing, 1989:616-17
5. Elin R. Magnesium: The fifth by forgotten electrolyte. Am J Clin Pathol 1994;102:616-22
6. Abraham G, Flechas J. Management of fibromyalgia: Rationale for the use of magnesium and fibromyalgia. J Nutr Med 1992; 3(1):49-59
7. Cox L. Red blood cell magnesium and chronic fatigue syndrome. Lancet 1991;337:757-60
8. Mausner J, Kramer S. Epidemiology- An Introductory Text. 2nd edition. Philadeophia: WB Saunders, 1985:4
9. Dorland's Medical Dictionary. 25th edition. Philadelphia: WB Saunders, 1974:683