The RDAs or Recommended Dietary Allowances of vital nutrients such as vitamins and minerals, are being promoted by health authorities as the level of consumption at which we may feel comfortable about having "taken care of our needs" - but is that really the truth?
Developed during the 1940s, the purpose of RDAs was to identify a diet that would allow US soldiers to fight as well as those staying home to survive without getting sick from malnourishment. After the war, dietary allowances became a part of standard health practice in many western countries. Note that there was no intention to assure optimum health, merely the absence of those deficiency diseases that had been identified at the time. Although refinements have taken place over the years, the basic philosophy of RDAs has remained the one implicit in the original purpose.
Legislation proposed in the international food standards body, the Codex Alimentarius and in a regional context, such as the European Food Supplements Directive, the Australia/New Zealand trans-tasman harmonization of health products regulation and a Canadian health products initiative propose to "ensure the safety" of those vitamins and minerals we can add to our daily food. There is talk of limiting, for safety reasons, the available dosage of supplements, so the question becomes quite legitimate: What is safer, a low dose (RDA level) vitamin intake or a high dose (optimised) intake of these nutrients?
Vitamin Safety, RDAs and the Assault on Vitamin Freedom
by James South, M.A.
Once again, the right of Americans to purchase high potency nutritional supplements is under attack. The enemies of supplement freedom, such as U.S. Senators Richard Durbin (D-Ill.) and Hillary Clinton (D-N.Y.), and Representatives John Dingell (D-Mich.) and Henry Waxman (D-Calif.), are pushing bills in Congress (SB 722 and HR 3377) that would empower the FDA to ban almost any supplement, as well as force costly pre-marketing approval and post-marketing surveillance on the vitamin industry that would radically increase supplement prices.1
Indeed, the proposed regulations would be more restrictive than those governing the prescription and over-the-counter drug industries! Underlying this assault on vitamin freedom is the (erroneous) belief that nutritional supplements are extremely dangerous, and that only nutrients with an officially defined DRI (dietary reference intake), at levels no more than 150 percent of the DRI, should be allowed to be sold.
To add insult to injury, the Institute of Medicine of the National Academy of Sciences, which sets the DRIs for various nutrients, is proposing a drastic lowering of the DRI for all nutrients. The term “DRI” actually refers to a group of related reference standards, including the Recommended Dietary Allowance (RDA) and Estimated Average Requirement (EAR). The Institute of Medicine is recommending that the national standard for nutrient intake be shifted from the RDA to the EAR.2
As noted in the DRI handbook, the RDA “… is the average dietary intake level that is sufficient to meet the nutrient requirement of nearly all (97 to 98 percent) healthy individuals ” (emphasis added).3 “The EAR is the daily intake value that is estimated to meet the requirement...in half of the healthy individuals in a...group. At this level of intake, the other half of a specified group would not have its nutritional needs met.”4 Thus, the new DRIs, which the FDA uses to set its daily reference intake, will be significantly lower than the already low current RDA-DRIs.
The assault on vitamin freedom has always revolved around two key questions: Is the RDA (DRI) level of nutrient intake adequate to promote robust, vibrant, high energy optimal health, and are high potency vitamin supplements really safe?
The National Academy of Sciences and the FDA have been setting RDAs since 1943, revising them periodically. The 1989 RDA revisions lowered many RDAs from their 1980 levels.
For example, the 1989 RDA for folic acid was reduced from 400 to 200 mcg, a level more in line with average U.S. consumption of folic acid.5 The 1989 RDA for vitamin E was reduced from 30 IU to 15 IU, with typical U.S. intakes being 10-15 IU (7-10 mg).6
The general lowering of the (already modest) RDAs in the 1989 revisions was based in part on the question-begging “logic” that assumes Americans are a basically healthy people, and since they routinely fail to consume diets containing the earlier, higher RDAs of most nutrients, the new, lower RDAs are all that is necessary for good health. (The DRIs set from 1998-2003 are generally the same or lower than the 1989 RDAs.)
In a land where $1.6 trillion (almost one sixth of total national income) is spent annually on “health” (i.e., disease) care; where cancer is one of the leading causes of death in children; where one-third of the population is medically obese; where many tens of millions suffer from diabetes, asthma, allergies, arthritis, ulcers/heartburn, chronic insomnia, depression, alcoholism, drug addiction, heart disease, high blood pressure and cancer, to assume that Americans are healthy just because they don’t suffer classical nutritional deficiency diseases such as scurvy (vitamin C), rickets (vitamin D), or beri-beri (vitamin B1), is rather Alice-in-Wonderland “logic,” indeed.
There is, however, a deeper conceptual and scientific falseness to the RDAs beyond their recent specious downward revisions. Part of the problem stems from the conceptual framework of the RDAs as such. The 1980 Recommended Dietary Allowances states:
RDAs are recommended for healthy populations. Special needs for nutrients arising from such problems as premature birth, inherited metabolic disorders, infections, chronic diseases and the use of medications require special dietary and therapeutic measures. These conditions are not covered by the RDAs…. The requirement for a nutrient is the minimum intake that will maintain normal function and health…. For certain nutrients, the requirements may be assessed as the amount that will just prevent failure of a specific function or the development of specific deficiency signs—an amount that may differ greatly from that required to maintain maximum (i.e., optimum) body stores” (emphasis added).7 With regard to the first three statements, since the majority of Americans suffer chronic diseases such as diabetes, heart disease, arthritis, allergies, asthma, depression, etc., and routinely use over-the-counter or prescription medications such as aspirin, allergy medications, antacids, laxatives, anti-depressants, high-blood pressure drugs, statin-drugs, etc., then, by the RDA Committee’s own statement the RDAs are inadequate for their required nutrient intake.
The last two statements focus on minimum nutrient intake, and on (just barely) avoiding specific physiologic function failure and/or specific nutritional deficiency symptoms. This makes it clear that the RDAs were never formulated as a guide to maintaining robust, vibrant, high energy optimal health, but are merely intended to keep people “healthy” enough to (just barely) avoid classical nutritional deficiency diseases such as scurvy or pellagra, or to avoid their heart or liver or brain failing today or tomorrow—but who knows about next month or next year?
Five Stages of Nutrient Deficiency
In 1964 Myron Brin published a classic analysis of the five stages in the development of a vitamin or nutrient deficiency. He illustrated the schema with reference to vitamin B1 (thiamin).
In the first, or preliminary stage, inadequate B1 availability due to faulty diet, malabsorption or abnormal metabolism leads to a greatly reduced urinary B1 loss. In the second, or biochemical stage, the activity of a key enzyme—transketolase—which is activated by B1, is significantly reduced. Adding B1 to a blood sample from a person at this stage increases his or her transketolase activity. In the third, or physiologic stage, various general symptoms develop, such as lessened appetite, insomnia, increased irritability, and malaise. In the fourth, or clinical stage, a constellation of symptoms classically specific to B1 deficiency disease (beri-beri) develops: e.g., intermittent claudication, polyneuritis, bradycardia, peripheral edema, and ophthalmoplegia. In the fifth, or anatomical stage, histopathological changes due to cellular structural damage are seen, such as cardiac hypertrophy, degeneration of the cerebellar granule layer, and swelling of the microglia.8
Although Brin’s five-stage deficiency schema is exemplified with regard to B1, it is in principle applicable to any nutrient, as Brin himself notes. Brin’s schema is especially illuminating with regard to the RDAs, since the “just preventing failure of specific functions” and “just preventing specific deficiency signs” criteria of nutritional requirement, which is the basis of the RDA concept, are only evidenced in the fourth (clinical) and fifth (anatomical) stages of developing nutritional deficiency disease.
The first three stages, although they are objectively, empirically measurable and observable phases of a developing nutrient deficiency, do not involve either “specific deficiency symptoms” or “failure of a specific nutrient-related function.” What follows from this is quite simple. The RDA level of nutrient intake may keep most people out of the severe illness-leading-to-death fourth and fifth nutrient deficiency stages, but RDA nutrient levels cannot be presumed to be adequate to keep one out of the first three stages of “subclinical” deficiency, let alone in a more optimal, vibrant, energized state of health.
Genetic Need for High-Dose Vitamins
A recent major scientific review article by famed nutrition researcher Bruce Ames and colleagues makes it clear that for many people, the RDAs will not be sufficient even to avoid major nutrient-related illness and death. Noting that a key function of many vitamins, minerals and nutrients is to activate the metabolic enzymes on which all life depends, the Ames group reports that about 50 human genetic diseases caused by defective enzymes can be remedied or ameliorated through high-dose nutrient therapy, which at least partially restores defective enzyme activity.9
Ames and coworkers point out that an alternate form of a gene which is present in 1 percent or more of the population is called a “polymorphism.” They state:
Our analysis of metabolic disease that affects cofactor [nutrient] binding, particularly as a result of polymorphic mutations, may present a novel rationale for high-dose vitamin therapy, perhaps hundreds of times the normal dietary reference intake (DRI) in some cases. This area should interest the entire health community because of the considerable percentage of the population affected by polymorphisms…. The setting of a DRI may become more complicated if a sizable percentage of the population in fact has a higher B-vitamin requirement because of a polymorphism…. It also seems plausible that for each example of a genetic disease or polymorphism clearly involving derangement of metabolism, multiple forms of the disease exist that reflect [only] slight changes in [genetically defective enzyme activity] but that are not commonly thought of as genetic diseases…. The administration of high doses of vitamins may reverse, at least partially, many more genetic diseases than those described here.... Provided safe dosages are used…there is potentially much benefit and possibly little harm in trying high-dose nutrient therapy because of the…low level of risk. Most of the vitamins discussed here appear safe in relatively high doses because the body can discard excess.”9
Given the large number of case reports analyzed in the Ames article, the question becomes less “Are high dose vitamins safe?” than “For many people, are RDA-only vitamin levels safe?” The Ames group reports a myriad of cases with people being snatched from the jaws of death or crippling disease by megadose (10-500X RDA) nutrient therapy, who would have perished or suffered irreparable harm on mere RDA vitamin doses. And some of the genetic enzyme defects discussed in the Ames article may affect millions of people—e.g., those leading to homocysteinemia.
The Ames group also comments on the safety of even megadose levels of many nutrients. They report that 500 mg of B6 per day for two years appears to be safe, but that 1,000 mg/day is probably the maximum.9 No safe upper limit (UL) for B1 has been set because of its relative safety.9 No UL has been set for B2 because there have been few reports of adverse effects even with doses in the hundreds of milligrams.9 Adverse effects of niacin (B3) usually occur at doses over 1,500 mg, with the niacinamide form of B3 being even safer.9 No toxicity of biotin has been reported with doses of 200 mg/day or less.9 B12 therapy with 5000 mcg or less has resulted in few adverse effects.9 Due to a lack of reports of adverse effects, no UL has been set for pantothenic acid.9 Adverse effects with vitamin E are rare below 1,500 IU/day.9 (In a 1988 review article on vitamin E safety, Bendich and Machlin noted virtually no side effects in six double-blind human studies even up to 3,200 IU/day).10 Vitamin D side effects typically occur at doses of 10,000-50,000 IU.9
Vitamin Safety: A Personal Note
I have been taking megadose vitamins since 1971. I have taken well over one million supplements in the last 33 years. For the first 10 years, I took (among other things) 1,000 mg B6 per day, 50,000-100,000 IU vitamin A per day, 100-150 mg zinc per day, 5,000 IU vitamin D per day, and up to 3,000 mg niacin per day. I have taken 8,000-25,000 mg vitamin C per day and 400-1,000 IU vitamin E per day for 33 years. I have taken 200-600 mg lipoic acid per day for 18 years. If the “vitamins over the RDA are poison” crowd were right, I would have been dead years ago from multinutrient toxicity. Yet I’m healthier in many ways at 56 than I was at 16. Even though I’m a devout carnivore, my blood cholesterol levels typically run 160-180, with triglycerides below 50.
Severe asthma and allergies that plagued me into my early 20s have been kept at bay for decades with megadose nutrients, yet they would come roaring back if the FDA/medical industrial complex succeeds in outlawing high dose vitamins.
It is the desire for ever more power over the American consumer that drives the FDA, along with its subservience to the pharmaceutical industry. And the pharmaceutical industry wants Americans to be forced to rely on high-profit patented drugs, rather than safer and cheaper nutrients, to control their health/diseases. The pharmaceutical industry is the most profitable legal industry in the world, with profit levels of 25-30 percent being common (most industries are lucky to make 5-10 percent profit).
The pharmaceutical industry wants to use the power of Congress and the FDA to give them a captive market, by outlawing vitamin supplement levels beyond the RDA. It was the grass-roots action of millions of Americans that stopped the FDA vitamin power-grab in 1976 by pressuring Congress to enact the vitamin-protecting Proxmire bill, and similarly prevented a 1994 FDA power-grab through pressuring Congress to enact the Dietary supplement Health and Education Act (DSHEA).
1. Natural Products Insider, vol. 9 no. 1, 2004:p. 19.
2. Ibid:p. 4.
3. Institute of Medicine. Dietary Reference Intakes for Thiamin…and Choline. National Academies Press, 2000:p. 18.
4. Ibid:pp. 18-19.
5. Subar, A. et al, “Folate intake and food sources in the US population”, Am J Clin Nutr, 1989, 50:508-16.
6. Crayhon, R. The Carnitine Miracle. NYC:M. Evans, 1998.
7. National Academy of Sciences. Recommended Dietary Allowances. Wash. D.C.:National Acad. Sci. Press, 1980:1-3.
8. Brin, M. “Erythrocyte as a biopsy tissue for functional evaluation of thiamin adequacy”. JAMA, 1964, 187:762-66.
9. Ames, B. et al, “High-dose vitamin therapy stimulates variant enzymes with decreased coenzyme binding affinity (increased Km): relevance to genetic disease and polymorphisms”. Am J Clin Nutr, 2002, 75:616-58.
10. Bendich, A. & Machlin, L. “Safety of oral intake of vitamin E”. Am J Clin Nutr, 1988, 48:612-619.
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