by Darlene Sherrell
NAS/NRC Institute of Medicine
Dietary Reference Intakes
|This page shows how data has been taken out of context and manipulated by special interests within the National Academy of Sciences in order to protect industry profits. The Institute of Medicine has misrepresented their own references concerning the “adequate” and the “tolerable” daily intake of fluoride. It’s a numbers game; easy to understand, easy to prove, and disastrous if ignored.|
What did the term “optimum daily fluoride intake” mean during the 1940s?
How does it compare with the new “adequate daily intake”?
American Council on Science and Health
Easley, Barrett, Munro, Kamrin, Whelan, Stare, et al
According to the National Research Council’s Institute of Medicine, “Since 1941, Recommended Dietary Allowances (RDAs) has been recognized as the most authoritative source of information on nutrient levels for healthy people. Since publication of the 10th edition in 1989, there has been rising awareness of the impact of nutrition on chronic disease. In light of new research findings and a growing public focus on nutrition and health, the expert panel responsible for formulation RDAs reviewed and expanded its approach … the result: Dietary Reference Intakes.”
» According to Dietary Reference Intakes: “The cariostatic effect of fluoride is a strong indicator for an Adequate Intake (AI) of the ion. … Enamel fluorosis is caused by excessive fluoride intake but only during the preeruptive development of the teeth. … reduction in the average number of dental caries per child was nearly maximal in communities having water fluoride concentrations close to 1.0 mg/liter. This is how 1.0 mg/liter became the “optimal” concentration. That is, it was associated with a high degree of protection against caries and a low prevalence of the milder forms of enamel fluorosis. The averge dietary fluoride intake by children living in optimally fluoridated communities was (and remains) close to 0.05 mg/kg/day (range 0.02 to 0.10 mg/kg/day; Table 8-1).”
» According to Dietary Reference Intakes: “Based on an AI for fluoride from all sources of 0.05 mg/kg/day and a reference weight for males ages 19 and over of 76 kg (Table 1-3), the AI is 3.8 mg/day. Based on a reference weight for females ages 19 and above of 61 kg, the AI for females is 3.1 mg/day.”
HOWEVER, the only reference for fluoride intake during the 1940s is McClure, and only a portion of McClure’s data is included in the DRI report. Excluded are the intake figures for older children and adults.
Ignoring the rest of McClure’s data, the DRI authors defy common sense by applying a one-size-fits-all mg/kg/day figure to everyone. Think of it as saying that if an eight-pound newborn baby needs one liter (2 pounds) of formula or breast milk each day, then by the time he weighs 160 pounds he’ll need 40 pounds of food each day. It just doesn’t work that way, but that’s what they did. They applied 0.05 mg/kg/day to everyone in order to make it look like we’ve always ingested as much fluoride as we do today in a fluoridated area. Any increase, they insist, has come from dental products … not food.
In 1989 the Institute of Medicine’s Recommended Dietary Allowances warned against the habitual ingestion of more than 4 mg of fluoride daily. At that time, the Adequate Intake was said to be 1.5 mg/day, based on McClure’s data from the 1940s. In other words, with no new research findings, the DRI authors have adjusted the figures, converting the Recommended Dietary Allowance (adequate intake in 1989) from 1.5 mg/day to 3.8 mg/day for adult males, and converting the tolerable upper level of intake from 4 mg/day to 10 mg/day for everyone aged eight and over. Obviously, “safe and adequate” is not based on conditions observed in the early 1940s in optimally fluoridated areas, but on industry’s ever increasing need for inexpensive disposal of toxic fluoride wastes, as well as the ever increasing use of fluoride-based pesticides and fungicides which leave residues on fruits and vegetables.
Clear increases in fluoride intake from sources other than dental products are flatly denied in the DRI report in order to protect current fluoridation policy. This is not scientific opinion, but simple arithmetic.
The following table contains the data published by McClure … director of the National Institute of Dental Research, and the only reference cited by the DRI committee for fluoride intake during the 1940s. How did McClure’s 1.5 mg/day become 3.8 mg/day?
|Total Daily Fluoride Intake … McClure 1943|
|1 – 3
4 – 6
7 – 9
10 – 12
|8 – 16
13 – 24
16 – 35
25 – 54
|0.390 – 0.560
0.520 – 0.745
0.650 – 0.930
0.810 – 1.165
|0.027 – 0.265
0.036 – 0.360
0.045 – 0.450
0.056 – 0.560
|0.417 – 0.825
0.556 – 1.105
0.695 – 1.380
0.866 – 1.725
|19+||61 – 76||0.800 – 1.200||0.200 – 0.300||1.0 – 1.5||0.02|
McClure, Frank J., Ingestion of fluoride and dental caries – quantitative relations based on food and water requirements of children 1 to 12 years old, American Journal Diseases of Children, 66:362, 1943.
In 1951 NAS/NRC wrote: “Under normal conditions of living, fluorine is a trace element in human nutrition (McClure, 1951). Minute amounts are absorbed from certain foods and drinking water and, to a limited extent, are retained by dental and osseous tissues. The quantity of fluorine ingested in food is a relatively unimportant variable; the average diet contains 0.2 to 0.3 mg. daily. Of greater import is the variable quantity ingested in drinking water.” Report of the Ad Hoc Committee on the Fluoridation of Water Supplies, Division of Medical Sciences, National Research Council, Nov. 29, 1951.
In 1953 NAS/NRC wrote: “Exclusive of drinking water, the average diet in the United States is calculated to provide 0.2 to 0.3 milligram of fluoride daily. … drinking water … can provide an optimal internal supplement of approximately onehalf to 1 milligram of fluoride per day. … a person drinking fluoridated water may be assumed to ingest only about 1 milligram per day from this source … the development of mottled enamel is, however, a potential hazard of adding fluorides to food. The total daily intake of fluoride is the critical quantity.” National Research Council, Pub. #294, November 1953.
In 1977 NAS/NRC wrote: “Recent studies indicate that the total intake of fluoride is as high as 3 mg/day rather than the earlier figure of 1.5 mg/day, primarily because of increases in the estimated levels of fluoride in food. (1970) Balance data presented by Spencer also suggest a higher retention by bone, nearly 2 mg/day rather than the 0.2 mg/day indicated earlier. … These findings are important . . . a retention of 2 mg/day would mean that an average individual would experience skeletal fluorosis after 40 yr, based on an accumulation of 10,000 ppm fluoride in bone ash.” [crippling phase] Drinking Water and Health, Safe Drinking Water Committee, National Academy of Sciences, NAS/NRC, 1977 p. 371-372
This concern was prompted by data such as that shown below, from a 1974 study which analyzed duplicate meals. The figures do not include non-meal foods or beverages. Dietary Fluoride In Different Areas in the United States, Kramer, Osis, Wiatrowski & Spencer, American Journal of Clinical Nutrition – 27:590-594, 1974.
|American Journal of Clinical Nutrition – 27:590-594, 1974|
|Corvalis, OR||0.60 ppm||3.44 mg/day|
|Milwaukee, WI||0.85 ppm||3.41 mg/day|
|Cleveland, OH||1.27 ppm||3.05 mg/day|
|Tuscaloosa, AL||0.76 ppm||2.94 mg/day|
|Madison, WI||1.11 ppm||2.88 mg/day|
|Iron Mountain, MI||0.08 ppm||1.03 mg/day|
The Role of the American Council on Science and Health
In 1978, in response to my concern regarding evidence of increasing fluoride intake, the Governor of Michigan ordered a joint review by the state’s public health and agriculture departments.
If fluoride intake had increased from about one milligram per day to as much as three milligrams per day, even in non-fluoridated areas, people could be getting too much fluoride for their own good. Dental fluorosis rates were climbing. The director of the Michigan Department of Public Health wanted to be certain that I was wrong … that optimum still meant about a milligram a day – not three or more. If a typical diet was actually providing as much as 3.5 mg/day, we needed to know “what is a safe amount and how much is retained in the body.”
March 28, 1978, The Detroit News: “STATE STUDY TO FIND OUT IF WE’RE FLUORIDE OD’s – ‘We’re going to try to determine the changes in the average family market basket for the past 30 years, since the first studies of fluoridation were done,’ said Health Director Maurice Reizen. … According to Mrs. Sherrell, research has shown the average diet includes some 3.5 milligrams of fluoride. … Among the issues under study is how much fluoride is being taken in by Michigan residents, what is a safe amount and how much is retained in the body. … Should overdoses of the chemical be indicated, Reizen said, either fluoride levels in water or in other products could be altered. In any event, he said, it would be a national problem.”
August 1, 1980, The State News: “VOTERS TO DECIDE ISSUE OF CITY WATER FLUORIDATION – ‘Her’s (Sherrell’s) is a legitimate concern,’ said Reizen. ‘In the past couple of decades, the amount of fluoride in food has increased, so we are doing studies to determine if the amount in the water should be reduced … but even at the optimum, there will still be people who will be sensitive to fluoride and will just have to avoid it,’ Reizen said.”
June 16, 1981, Lansing State Journal: “FLUORIDE MONITORING URGED – Whether fluoride is attacking the body while protecting the teeth still has the state government’s science advisors puzzled. While fluoridation won a generally clean bill of health from Dr. Michael Kamrin, a warning flag was run up by Norman Zimmerman of the state Toxic Substance Control Commission (TSCC). ‘I couldn’t find too many problems in terms of safety,’ reported Kamrin, a visiting scientist at the Office of Legislative Science Advisor. ‘We don’t have any evidence in this country that fluoride has caused ill effects.’ … Zimmerman, a toxicologist reviewed Kamrin’s findings for the senators. ‘Really, this is a very toxic chemical,’ cautioned Zimmerman, ‘I do think it’s important to monitor the total (fluoride intake) level just like any drug.’ He suggested communities considering fluoridation study natural fluorides already being ingested in their areas and urged cities already fluoridating without such studies to undertake them. … Two years ago, the governor’s Task Force on Fluorides found fluoride intake by adults in Michigan ranged from two to five parts per million. … Besides food and aluminum plants, he added, significant fluoride releases have been found from uranium enrichment facilities, gypsum ponds and coal-fired power plants.”
Michael Kamrin, Michael Easley, Stephen Barrett, and Ian C. Munro are science and policy advisors for the industry front known as the American Council on Science and Health. Ian C. Munro represented ACSH during the preparation of Dietary Reference Intakes for the Institute of Medicine. Twenty years earlier, Michael Kamrin had served the same master when he claimed the discrepancies between the figures published in the 1940s and the figures published at a later date were the result of more precise tests, and not an actual increase in fluoride from sources other than dental products. The amount of fluoride in food had remained the same, he said.
I challenged this claim because the figures had always included several decimal places, the studies had involved thousands of people, and pre-employment physical examinations in the major fluoride polluting industries had subsequently shown a steady increase in urinary fluoride levels among job applicants. Increases in urinary fluoride levels among the general population are a reliable indicator of increases in daily intake. The extra fluoride had to be coming from somewhere. Furthermore, the early studies measured fluoride intake as well as fluoride excretion via urine. Although advanced technology may have added a few decimals, what goes on to the right of the decimal place has no effect on the whole number to the left. The conclusion presented by Michael Kamrin didn’t make any sense. As a result, the following statement appeared in a subsequent review by Michigan’s Toxic Substance Control Commission.
“In communities considering fluoridation of the water supply, studies should be undertaken to determine ambient fluoride and estimated intake by a cross-section of the population. In communities using fluoridated water such studies, if not previously performed, should be conducted. … In communities with fluoridated water, the intake could be as much as 5.7 times the fluoride in the water.” Norman Zimmerman, Ph.D., J.D., Senior Toxicologist, Toxic Substance Control Commission (Michigan), The need for the determination of the extent of total fluoride exposure in community assessment of the value of water fluoridation, May 1981
NAS/NRC Corrects One Major Error in 1993
but the DRI authors pretend it didn’t happen
In 1977, as noted earlier, the National Academy of Sciences stated that about five milligrams of fluoride daily could cripple the average individual after 40 years. A series of letters between myself and the Institute of Medicine, dated 1989 to 1991, revealed that Roholm’s data is the only data used by the National Academy of Sciences in estimating the crippling daily intake of fluoride. There have been no meaningful studies since Roholm, and nothing in the industrial health journals to contradict his findings.
Unfortunately, Roholm’s mg/kg/day dosage figures were converted to mg/day figures by Harold C. Hodge, former Chairman of the Toxicology Committee for the National Academy of Sciences, National Research Council. It appears that Hodge neglected to convert pounds to kilograms when he applied body weights to Roholm’s basic data. For many years Hodge’s “20-80 mg/day” error was picked up and repeated in numerous reviews, including the pre-publication version of Dietary Reference Intakes. Fortunately, however, Hodge corrected his own error in 1979, and NAS/NRC published their correction in 1993 in Health Effects of Ingested Fluoride.
In 1979 Harold Hodge wrote a chapter for a book titled Continuing Evaluation of the Use of Fluorides. According to Hodge, “Among the many effects of fluoride (real or purported) are a few that have been so well studied that quantitative dose-effect relations can be estimated albeit with variable numerical certainty. Only three of these effects have been observed in man: acute poisoning -death following a single dose; chronic poisoning -crippling fluorosis, the final stage of advanced osteofluorosis, first detectable as an increase in the radio-graphic density of the skeleton (osteosclerosis); and dental fluorosis. Five other chronic fluoride effects have been well studied in experimental animals: kidney injury, anemia, interference with reproduction, changes in thyroid structure or function, and body weight loss.” Hodge corrects his 1953 error in calculating Roholm’s mg/day figures here as well, when he states, “Crippling fluorosis as an occupational disease follows exposures estimated at 10 to over 25 mg of fluoride daily during periods of 10-20 years.” Harold C. Hodge, Ph.D., The Safety of Fluoride Tablets or Drops, Continuing Evaluation of the Use of Fluorides, AAAS Symposium, Boulder, CO, Westview Press, 1979.
In 1991 the U.S. Public Health Service (USDHHS) published Review of Fluoride Benefits and Risks, reporting a range in fluoride intake up to 6.6 mg/day in an optimally fluoridated area. “The daily intake of most adults is about equally divided among food, drinking water, beverages, and mouthwash.”
In 1993 NAS/NRC said, “When bone-ash fluoride concentrations are 7,500-8,000 ppm or more, stages 2 and 3 of skeletal fluorosis are likely to occur. The clinical signs of these stages are chronic joint pain, dose-related calcification of ligaments, osteosclerosis, possible osteoporosis of long bones, and in severe cases, muscle wasting and neurological defects. Crippling skeletal fluorosis might occur in people who have ingested 10-20 mg of fluoride per day for 10-20 years.” Health Effects of Ingested Fluoride, Subcommittee on Health Effects of Ingested Fluoride, Committee on Toxicology, Board on Environmental Studies and Toxicology, Commission on Life Sciences, National Research Council, August 1993, p.59
The only reference cited by the National Academy of Sciences is Roholm … and/or Hodge’s version of Roholm. The table below shows the minimum dosage, by body weight and years of exposure, which resulted in phase 3 crippling skeletal fluorosis among Roholm’s cryolite workers.
Minimum Fluoride Intake Which Causes
Crippling Skeletal Fluorosis Among Healthy Individuals
according to NAS/NRC references
|author||grand total||based on|
|Roholm||36,525 mg||0.2 mg/kg/day for 11 years|
|Hodge 1979||36,525 mg||10 mg/day for 10 years|
|NAS/NRC 1993||36,525 mg||10 mg/day for 10 years|
|100 lb person||36,525 mg||2.5 mg/day for 40 years|
|134 lb woman||48,944 mg||3.35 mg/day for 40 years|
|168 lb man||61,362 mg||4.2 mg/day for 40 years|
In 1993 the U.S. Public Health Service stated, “Existing data indicate that subsets of the population may be unusually susceptible to the toxic effects of fluoride and its compounds. These populations include the elderly, people with deficiencies of calcium, magnesium, and/or vitamin C, and people with cardiovascular and kidney problems. … Because fluoride is excreted through the kidney, people with renal insufficiency would have impaired renal clearance of fluoride … Impaired renal clearance of fluoride has also been found in people with diabetes mellitus and cardiac insufficiency. People over the age of 50 often have decreased renal fluoride clearance. … This decreased clearance of fluoride may indicate that elderly people are more susceptible to fluoride toxicity. … Because of the role of calcium in bone formation, calcium deficiency would be expected to increase susceptibility to effects of fluoride.” Toxicological Profile for Fluorides, Hydrogen Fluoride, and Fluorine (F), (April 1993), U.S. Dept. Health and Human Services, Agency for Toxic Substances and Disease Registry, p.112
“It is no longer feasible to estimate with reasonable accuracy the level of fluoride exposure simply on the basis of concentration in drinking water supply.” National Research Council, Health Effects of Ingested Fluoride, August 1993.
The Dietary Reference Intakes committee is recommending we ingest enough fluoride to cause serious adverse health effects which are openly acknowledged. They assure us that the crippling daily dosage is a tolerable upper limit for safety.
Just a few years ago the same Institute of Medicine set their tolerable upper limit at 4 mg/day, based on the old erroneous 20-80 mg/day figures which Hodge had corrected in 1979. Now, instead of correcting the maximum tolerable intake figure downward to provide a margin of safety, the Institute of Medicine, under the guidance of industry representative Ian C. Munro, has adjusted the figure upward to compensate for the needs of industry. The fact is, we are being exposed to a great deal more fluoride from both air pollution and agricultural products, as well as dental products and drugs. Pesticide residues alone can exceed the recommended optimum daily fluoride intake for both children and adults.
The facts are being swept under the rug in this latest subterfuge meant to protect water fluoridation. There appears to be a relentless effort to avoid studies capable of determining the current range in fluoride intake among children. Surprisingly, there is no record of any studies conducted in the past using methods capable of detecting early cases of skeletal fluorosis among the general population. In 1945 McClure commented, “epidemiological studies of the nondental effects of fluorine, as ingested in fluoride domestic waters, are extremely few in number and very limited in scope.” Nothing had changed by 1977, when the National Research Council commented on inadequate safety studies as follows: “Without statements about the power of the tests, the implication of finding noeffect is construed to be that no effect exists… further study is indicated.”
» According to Dietary Reference Intakes: “Although some recent recommendations have been made for additional research in the areas of intake, dental fluorosis, bone strength, and carcinogenicity, extensive reviews of the scientific literature revealed no adverse effects unless fluoride intakes were greater than 10 mg/day for 10 or more years (Kaminsky et al., 1990; NRC, 1993; USPHS, 1991).”
» According to Dietary Reference Intakes: “Derivation of the UL. The risk of developing early signs of skeletal fluorosis is associated with a fluoride intake greater than 10 mg/day for 10 or more years. Therefore, a UL of 10 mg/day was established for children older than 8 years and for adults. Data from studies of fluoride exposure from dietary sources or work environments (Hodge and Smith 1977) indicate that a UL of 10 mg/day for 10 or more years carries only a small risk for an individual to develop preclinical or stage 1 skeletal fluorosis.”
» According to NAS/NRC’s 1993 Health Effects of Ingested Fluoride, as well as Hodge 1979, 10 mg of fluoride per day is enough to cause stage 3 crippling skeletal fluorosis (CSF). The table below shows the total daily fluoride intake associated with the development of CSF … according to body weight and years of exposure.
|Minimum Daily Fluoride Intake
Associated With Phase III Skeletal Fluorosis
|National Research Council, 1977 and 1993;
Harold C. Hodge, 1979;
Kaj Roholm, 1937
Note: Intake figures by body weight for 44 years are shown here for the purpose of comparison only.
- Fluoridation Facts, American Dental Association, 1993.
- Recommended Dietary Allowances, National Research Council, 1980, 1989.
- The Safety of Fluoride Tablets or Drops, Harold C. Hodge, Continuing Evaluation of the Use of Fluorides, AAAS Symposium, Boulder, CO, Westview Press, 1979.
- Ingestion of fluoride and dental caries … quantitative relations based on food and water requirements of children 1 to 12 years old, Frank J. McClure, American Journal Diseases of Children, 66:362, 1943.
- Report of the Ad Hoc Committee on the Fluoridation of Water Supplies, Division of Medical Sciences, National Research Council, Nov. 29, 1951.
- The problem of providing optimum fluoride intake for prevention of dental caries, Food and Nutrition Board, Division of Biology and Agriculture, National Academy of Sciences, National Research Council, Pub. #294, November 1953
- Health Effects of Ingested Fluoride, Subcommittee on Health Effects of Ingested Fluoride, Committee on Toxicology, Board on Environmental Studies and Toxicology, Commission on Life Sciences, National Research Council, August 1993.
- Biologic Effects of Atmospheric Pollutants FLUORIDES, Committee on Biologic Effects of Atmospheric Pollutants, Division of Medical Sciences, National Research Council, National Academy of Sciences, Washington, D.C., 1971 p 214
- Drinking Water and Health, National Research Council, 1977
- Fluorides and Human Health, World Health Organization, 1970, pp 32, 239-240.
- Non Dental Physiological Effects of Trace Quantities of Fluorine, Frank J. McClure, Journal American College of Dentists – 12:50, (1945).
- Fluoridation of Water, Special report by Bette Hileman, Chemical & Engineering News -August 1, 1988 p 35-36
- See image of World Health Organization map showing fluoride content of water supplies in India prior to 1970.
- Dietary Reference Intakes National Research Council, 1997, Prepublication Copy at: http://www.nap/readingroom
- Dietary Fluoride In Different Areas in the United States, Kramer, Osis, Wiatrowski & Spencer, American Journal of Clinical Nutrition – 27:590-594, 1974
- Toxicological Profile for Fluorides, Hydrogen Fluoride, and Fluorine (F), (April 1993), U.S. Dept. Health and Human Services, Agency for Toxic Substances and Disease Registry, p.112
- Endemic Dental Fluorosis or Mottled Enamel, Dean, H. Trendley, Journal American Dental Association, 30:1278, 1943
- The Fluoride Content of Some Foods and Beverages, Journal of Food Science 31:941, 1966
- Review of Fluoride Benefits and Risks, U.S. Department of Health and Human Services, 1991