![[Feedback]](/icons/banner/feedbackACT.gif){kind=icon}
![[For Subscribers]](/icons/banner/subscriberACT.gif){kind=icon}
![[Archive]](/icons/banner/archiveACT.gif){kind=icon}
![[Search]](/icons/banner/searchACT.gif){kind=icon}
![[Contents]](/icons/banner/tocACT.gif){kind=icon}
|
|
|
|
|
||
Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI 53706
2To whom correspondence should be addressed. E-mail: jlgreger{at}facstaff.wisc.edu
 |
ABSTRACT |
|---|
 TOP ABSTRACT INTRODUCTIONAre consumers taking charge...Which Americans are most...Can educators use consumer...What should we teach...Who should provide information...REFERENCES |
|---|
, Gilbert 1999
).
2) The characteristics of supplement users have been
profiled in numerous academic and industrial surveys. However, even the
best models based on consumers’ characteristics can predict < 30% of diet-related behavior (Baranowski et al. 1999
). 3) Experts in traditional medicine and
nutrition lack information on supplements and herbals. The Practice and Policy Guidelines Panel of the National Institute of Health Office of Alternative Medicine (1997)
stated that practices used in complementary
and alternative medicine were "unsuitable for the development of
evidence-based practice guidelines." Well-designed basic and
clinical research is needed on the efficacy, bioavailability and safety
of supplements and herbal medications. 4) It is
debatable which agencies and professionals are the best gatekeepers of
information on supplements and herbals. Significant numbers of
consumers do not seem to rely on their physicians for information on
alternative forms of medicine (Eisenberg 1997
). Despite
the obstacles, the traditional medical community (including
nutritionists) should focus more research efforts on diet supplements
and herbal treatments and increase training on these topics for
students majoring in health care fields. Then health care professionals
can mount high quality, targeted education programs for consumers.
KEY WORDS: • supplements • herbal treatments • consumers • education models • bioavailability
|
INTRODUCTION |
|---|
|
TOPABSTRACTINTRODUCTIONAre consumers taking charge...Which Americans are most...Can educators use consumer...What should we teach...Who should provide information...REFERENCES |
|---|
, Gilbert 1999
). It is likely that the trends observed in the use of
nutrients supplements and herbals reflect this larger trend.
).
Thus, consumer education efforts, even when focused, are apt to have
limited success.
stated that practices used in complementary and
alternative medicine were "unsuitable for the development of
evidence-based practice guidelines." More research is needed on
the efficacy, toxicity and bioavailability of supplements and herbal
medicines.
). Experts also do not agree on the best way to advertise
dietary supplements (Dickinson 1999
, Mitka 1998
, Nestle 1999
).
Thus, the initial question in this manuscript splits into a series
of questions (Table 1
). The answers to these questions are still being developed by
investigators in a broad range of fields that includes nutrition,
medicine, pharmacology, education, sociology and marketing.
|
|
Are consumers taking charge of their health? |
|---|
|
TOPABSTRACTINTRODUCTIONAre consumers taking charge...Which Americans are most...Can educators use consumer...What should we teach...Who should provide information...REFERENCES |
|---|
) estimated that Americans made
$10.3 billion of out-of-pocket expenditures for unconventional
medicine, including diet supplements, herbals and service by providers
of unconventional therapy. These expenditures were 44% as great as of
the out-of-pocket expenditures for physician services ($23.3 billion).
In 1998 Eisenberg et al. (1998
) called these procedures
and services alternative medicine, not unconventional medicine. They
estimated that the out-of-pocket expenditures of U.S. consumers for
alternative medicine in 1997 had more than doubled since 1990 and were
between 27 and $34.4 billion. In contrast, out-of-pocket expenditures
of consumers for traditional physician services increased at a slower
rate and were $29.3 billion in 1997.
Not all categories of alternative medicine treatments grew equally
between 1990 and 1997. The U.S. Nutraceutical Report 1997 indicated
sales of functional foods and dietary supplements increased 62 and
40%, respectively, between 1992 and 1996 (Anonymous
1998
). Similar trends were observed in Western Europe and Japan
(Table 2
).
|
reported that
although only 2.5% of adults in the United States reported using herbs
in the past 12 mo in 1990, 12.1% did in 1997. The 1999 HealthFocus
Trend Report indicated that 35% of U.S. adults used herbals in 1998
(Gilbert 1999
). On the basis of the 1986 National Health
Interview Survey, Moss et al. (1989)
estimated that 36%
of U.S. adults consumed nonprescription vitamin and minerals. The 1999
HealthFocus Trends Report indicated that 48 and 54% of American used
vitamin/mineral supplements once a week in 1990 and 1998, respectively
(Gilbert 1999
). Kim et al. (1999)
observed that the apparent increased use of supplements reflected not
just the "passage of time" but also the changing demographics of
those surveyed.
Other smaller surveys have indicated that 3–93% of the groups studied
used herbals, vitamins or diet supplements (Lyle et al. 1998
, Rock et al. 1998, Winslow and Kroll 1998
). The prevalence of supplement use varied with the
populations, the definition of supplements and the definition of what
constituted regular supplement usage.
|
Which Americans are most apt to consume supplements? |
|---|
|
TOPABSTRACTINTRODUCTIONAre consumers taking charge...Which Americans are most...Can educators use consumer...What should we teach...Who should provide information...REFERENCES |
|---|
,
Koplan et al. 1986
, Lyle et al. 1998
,
Medeiros et al. 1989
, Moss et al. 1989
,
Newman et al. 1998
, Slesinski et al. 1995
, Stewart et al. 1985
, Subar and Block 1990
). Although supplement users tend to be more
educated, researchers have demonstrated no correlation (Kim et al. 1999
, Schutz et al. 1986) or a negative
correlation (Barr 1986
) between supplement use and
nutrition knowledge.
A few investigators have attempted to characterize the attitudes toward
nutrition and health of supplement users. Patterson et al.
(1998)
reported that supplement users were more apt to
have a strong belief in diet-cancer connections than were nonusers.
However, surveyed individuals more often cited health promotion or
taking control of their health rather than disease prevention (except
for the prevention of colds) as a reason for using supplements or herbs
(Hensrud et al. 1999
, Schutz et al. 1982
). Consumers may perceive plant products to be more natural
than manufactured medicines (Winslow and Kroll 1998
).
Supplement use has also been related to various health-related
behavior patterns. Generally, positive lifestyle factors were
associated with increased supplement usage. For example, nonsmokers
were more apt to take supplements than were current smokers
(Lyle et al. 1998
, Patterson et al. 1998
,
Slesinski et al. 1995
, Subar and Block 1990
). Individuals who consumed either no alcohol or moderate
amounts of alcohol (less than seven servings of alcohol/wk) were more
apt to use supplements than were those who consumed more alcohol
(Lyle et al. 1998
, Newman et al. 1998
,
Subar and Block 1990
). Patterson et al.
(1998)
reported that individuals who used various
cancer-screening tests were more apt to ingest supplements.
Individuals who exercised regularly (strenuously at least three
times/wk) were more apt to take supplements in some (Lyle et al. 1998
, Patterson et al. 1998
) but not all studies
(Willett et al. 1981
). Barr (1986)
reported that 75% of the marathon runners and 64% of the fitness
class participants who she studied used supplements and average intake
was more than two supplements daily.
Those individuals who seem to be more sensitive to dietary messages
(such as maintain optimal weight, consume adequate levels of
micronutrients and eat fruits and vegetables) may also be more apt to
consume supplements. For example, individuals who were overweight or
had high body mass indices were less apt to take dietary supplements
than were thinner individuals in most (Lyle et al. 1998
,
Newman et al. 1998
, Moss et al. 1989
,
Subar and Block 1990
) but not all studies
(Willett et al. 1981
). Several groups have noted that
supplement users tended to consume more nutrient-dense diets
(especially for nutrients contained in the supplements) than did
nonusers (Koplan et al. 1986
, Looker et al. 1988
, Lyle et al. 1998
, Rock et al. 1997
). Supplement users have been reported to consume more
fruits and/or vegetables (Joshipura et al. 1999
,
Looker et al. 1988
, Lyle et al. 1998
,
Patterson et al. 1998
) and to consume less dietary fat
(Lyle et al. 1998
, Patterson et al. 1998
,
Rock et al. 1997
) than nonsupplement users.
The relationship of health status to supplement usage is complex.
Individuals who reported their health to be excellent or very good were
more apt to use supplements than were those who reported poor health
(Bender et al. 1992
, Moss et al. 1989
).
In contrast, Bender et al. (1992)
also reported that
that supplement usage was more likely among individuals with one or
more health problems. However, Lyle et al. (1998)
reported that generally individuals with hypertension, cancer or heart
disease did not use more supplements than did individuals without these
conditions. These apparent inconsistencies may reflect the importance
of age, seriousness of conditions and time since diagnosis. For
example, men between 43 and 54 y of age with a history of heart
disease were more apt to use multinutrient supplements and women older
than 75 y with a history of cancer were more apt to consume
supplemental vitamin E (Lyle et al. 1998
). Newman et al. (1998)
noted that the use of nutrient supplements and herbals by women
with breast cancer declined with time after diagnosis. Patients with
more advanced stages of cancer were more apt to use nonnutritional
supplements, such as shark cartilage (Newman et al. 1998
).
|
Can educators use consumer profiles to plan education and intervention programs? |
|---|
|
TOPABSTRACTINTRODUCTIONAre consumers taking charge...Which Americans are most...Can educators use consumer...What should we teach...Who should provide information...REFERENCES |
|---|
hypothesized that health intervention programs
should be matched to each individual’s stage of change in the
transtheoretical model (Table 3
). However, Baranowski et al. (1999)
reported that
assessing the stage of change of participants in dietary intervention
programs was often difficult. For example, is an individual who has
used megavitamin supplements or large doses of herbals with only minor
and nonspecific adverse effects in a precontemplation stage? Just
creating an awareness of potential adverse interactions among
supplements and herbals may be the most reasonable goal. Are consumers
at the preparation or action stage when they are selecting herbals at a
pharmacy? Would this be an effective time to provide information on the
bioavailability of various products?
|
). |
What should we teach about complementary and alternative medicine? |
|---|
|
TOPABSTRACTINTRODUCTIONAre consumers taking charge...Which Americans are most...Can educators use consumer...What should we teach...Who should provide information...REFERENCES |
|---|
noted that targeting the audience
was the first step in planning a health intervention program; the
second was deciding on the content of the educational message. This is
problematic because experts do not know what constitutes optimal
complementary and alternate medicine practices (Angell and Kassirer 1998
, Fontanarosa and Lundberg 1998
).
Recently the Practice and Policy Guidelines Panel of the National Institutes of Health Office of Alternative Medicine
(1997)
stated that practices used in complementary and
alternative medicine were "unsuitable for the development of
evidence-based practice guidelines, in part because of the lack of
relevant outcomes data from well-designed clinical trials."
Experts in traditional medicine have recognized their lack of
information on herbal medications in a variety of ways in recent years.
The National Institutes of Health has created an Office of Alternative
Medicine and funded centers and clinical trials of popular herbal
medications (Marwick 1998
). In 1998 several major
medical journals published research evaluating the efficacy and the
potential toxicity of herbal medications (DiPaola et al. 1998
, Ernst 1998
, Miller 1998
,
Wilt et al. 1998
, Winslow and Kroll 1998
). Many investigators have reported that a number of common
plants (including mushrooms, soybeans and teas) may have
disease-preventing properties (Blot et al. 1997
,
Borchers et al. 1999
, Messina et al. 1998
). Unfortunately, scientists have only begun to identify
the active components in these herbal medicines and foods and to
standardize the amounts and bioavailability of active ingredients in
products. These research activities must be completed before
well-designed clinical trials can be conducted.
Our knowledge of the bioavailability and toxicity of micronutrients
also is incomplete. However, vitamin/mineral supplementation trials,
evaluations of food fortification programs and clinical and animal
studies of interactions among nutrients and other substances in food
provide considerable data on the bioavailability and toxicity of
micronutrients (Blot 1997
, Greger 1987
,
Mertz et al. 1994
, Patterson et al. 1997
,
Pfeiffer et al. 1997
, Sandström 1998
). These limited data were the basis of standards, such as
the Tolerable Upper Intake Levels established by the Food and Nutrition
Board (Yates et al. 1998
) and the position article of
the American Dietetics Association on vitamin and mineral
supplementation (American Dietetics Association 1996
).
Moreover, investigators have documented excessive intake of
micronutrients through supplementation in several surveys. In the
National Health Interview Survey, supplement users at the 95th
percentile consumed daily from supplements >2-fold the Recommended
Dietary Allowance
(RDA)3for vitamin A, 7-fold the RDA for riboflavin and 17-fold the RDA for
vitamin C (Subar and Block 1990
). Stewart et al. (1985)
found that individuals (at the 95th percentile)
who reported using specific nutrient supplements in a national
telephone survey consumed >5-fold the RDA for thiamin, riboflavin,
vitamin C, vitamin E, vitamin B-12, niacin, vitamin B-6 and iron. Rock et al. (1998) noted that a few (< 4.4%) women at risk
of breast cancer consumed potentially toxic levels daily of vitamin A,
vitamin B-6, iron and zinc.
Obviously some consumers need information on the potential toxicity of
megasupplemnts and herbals. The educational messages on diet
supplements for consumers should be evidence-based
(Fontanarosa and Lundberg 1998
), admit the limitations
of available data and emphasize what is important. Goodwin and Tangum (1998)
stated that the only important issues to
consumers using dietary supplements were efficacy, toxicity and cost of
treatments. Bioavailability is an aspect of both efficacy and toxicity.
Consumers should be alerted also to the potential that excessive levels
of some nutrients could be ingested in a combination of fortified
foods, nutraceuticals and supplements.
|
Who should provide information on supplements and herbal treatments to consumers? |
|---|
|
TOPABSTRACTINTRODUCTIONAre consumers taking charge...Which Americans are most...Can educators use consumer...What should we teach...Who should provide information...REFERENCES |
|---|
, Levy and Schucker 1987
, Schutz et al. 1986). Moreover,
Levy and Schucker (1987)
reported that individuals who
consumed more than two supplements daily were less likely to rely on
physicians than were individuals who consumed less than two supplements
daily.
Not only do many consumers not consider physicians a major source of
nutrition information, they also do not appear to report their usage of
supplements to physicians. Hensrud et al. (1999)
found
that 30.5% of patients reported use of supplements on a standard
medical questionnaire that was part of a routine physical. During a
more intensive survey conducted for research purposes, 61% of the same
patients reported use of supplements, including herbals. Eisenberg et al. (1993)
noted that 72% of patients who used
unconventional therapies did not inform their physicians.
Consumers may not rely on traditional health care providers for
information on dietary supplements for several reasons. Most physicians
receive limited training on clinical nutrition (Halsted 1999
) or on complementary and alternative medicine
(Wetzel et al. 1998
). Similarly, few graduate nutrition
programs offer a course on nonnutrient substances in food. Furthermore,
consumers may perceive that traditional health care providers have
negative attitudes toward alternative medical therapies (Goodwin and Tangum 1998
). Wetzel et al. (1998)
noted
that instructors in elective course on complementary or alternative
medicine should encourage medical students to communicate
professionally with alternative health care clinicians and should teach
students to talk to patients about alternative therapies. The same
advice should be given to nutrition professors.
Finally, the Dietary Supplement Health and Education Act of 1994
changed the type of information available to consumers on dietary
supplements. The Dietary Supplement Health and Education Act of 1994
allowed manufacturers (without preauthorization by the Food and Drug
Administration) to describe on the label how a product affects the
structure or function of the body but not to make claims in regard to
disease prevention. Manufacturers, federal officials and medical and
nutrition professionals have extensively debated the impact of this act
and the recently published Federal Trade Commission guidelines for
advertising (Angell and Kassirer 1998
, Dickinson 1999
, Mitka 1998
, Nestle 1999
).
The debate seems to have made consumers more interested in diet
supplements and to have encouraged them to change their behavior in
regard to supplement usage.
Now is the time for the medical community (including nutritionists) to focus more research efforts on herbal treatments and diet supplements and to increase training on these topics for students majoring in health care fields. Then health care professionals can mount high quality, targeted education and intervention programs for consumers.
|
FOOTNOTES |
|---|
3 Abbreviation: RDA, Recommended Dietary Allowance.
|
REFERENCES |
|---|
|
TOPABSTRACTINTRODUCTIONAre consumers taking charge...Which Americans are most...Can educators use consumer...What should we teach...Who should provide information...REFERENCES |
|---|
1. American Dietetics Association Position of the American Dietetics Association: vitamin and mineral supplementation. J. Am. Diet. Assoc. 1996;96:73-77[Medline]
2.
Angell M., Kassirer J. P. Alternative medicine—the risks of untested and unregulated remedies. N. Engl. J. Med. 1998;339:839-841
3. Anonymous U.S. nutraceuticals market expected to continue to grow. Nutraceuticals World 1998;1:38-42
4. Baranowski T., Cullen K. W., Baranowski J. Psychological correlates of dietary intake: advancing dietary intervention. Annu. Rev. Nutr. 1999;19:17-40[Medline]
5. Barr S. I. Nutrition knowledge and selected nutritional practices of female recreational athletes. J. Nutr. Ed. 1986;18:167-174
6. Bender M. M., Levy A. S., Schucker R. E., Yetley E. A. Trends in prevalence and magnitude of vitamin and mineral supplement usage and correlation with health status. J. Am. Diet. Assoc. 1992;92:1096-1101[Medline]
7. Blot W. J. Vitamin/mineral supplementation and cancer risk: international chemoprevention trials. Proc. Soc. Exp. Biol. Med. 1997;216:291-296[Medline]
8. Blot W. J., McLaughlin J. K., Chow W. H. Cancer rates among drinkers of black tea. Crit. Rev. Food Sci. Nutr. 1997;37:739-760[Medline]
9. Borchers A. T., Stern J. S., Hackman R. M., Keen C. L., Gershwin E. Mushrooms, tumors, and immunity. Proc. Soc. Exp. Biol. Med. 1999;221:281-293[Medline]
10.
DiPaola R. S., Zhang H., Lambert G. H., Meeker R., Licitra E., Rafi M. M., Zhu B. T., Spaulding H., Goodin S., Toledano M. B., Hait W. N., Gallo M. A. Clinical and biologic activity of an estrogenic herbal combination (PC-SPES) in prostate cancer. N. Engl. J. Med. 1998;339:785-791
11. Dickinson A. New FTC guidelines on dietary supplement advertising: a valuable restatement and explanation of current enforcement policy. J. Nutr. Educ. 1999;31:276-277
12.
Eisenberg D. M. Advising patients who seek alternative medical therapies. Ann. Intern. Med. 1997;127:61-69
13.
Eisenberg D. M., Davis R. B., Ettner S. L., Appel S., Wilkey S., Van Rompay M., Kessler R. C. Trends in alternative medicine use in the United States, 1990–1997: results of a follow-up national survey. J. Am. Med. Assoc. 1998;280:1569-1574
14.
Eisenberg D. M., Kessler R. C., Foster C., Norlock F. E., Calkins D. R., Delbanco T. L. Unconventional medicine in the United States: Prevalence, costs, and patient use. N. Engl. J. Med. 1993;328:246-252
15. Ernst E. Harmless herbs?. A review of the recent literature. Am. J. Med. 1998;104:170-178
16. Ferguson K. J. Health behavior. Wallace R.B. eds. Public Health & Preventive Medicine 14th ed. 1998:811-816 Appleton & Lange Stamford, CT.
17.
Fontanarosa P. B., Lundberg G. D. Alternative medicine meets science. J. Am. Med. Assoc. 1998;280:1618-1619
18. Gilbert, L. (1999)1999 HealthFocus Trend Report. HealthFocus, DesMoines, IA.
19.
Goodwin J. S., Tangum M. R. Battling quackery: attitudes about micronutrient supplements in American academic institutions. Arch. Intern. Med. 1998;158:2187-2191
20. Greger J. L. Food, supplements, and fortified foods: scientific evaluations in regard to toxicology and nutrient bioavailability. J. Am. Diet Assoc. 1987;87:1369-1373[Medline]
21. Halsted C. H. The relevance of clinical nutrition education and role models to the practice of medicine. Eur. J. Clin. Med. 1999;53:S29-S34
22. Hensrud D. D., Engle D. D., Scheitel S. M. Underreporting the use of dietary supplements and nonprescription medications among patients undergoing periodic health examination. Mayo Clin. Proc. 1999;74:443-447[Abstract]
23.
Joshipura K. J., Ascherio A., Manson J. E., Stampfer M. J., Rimm E. B., Speizer F. E., Hennekens C. H., Spiegelman D., Willett W. C. Fruit and vegetable intake in relation to risk of ischemic stroke. J. Am. Med. Assoc. 1999;282:1233-1239
24. Kim E. H., Schroeder K. M., Houser R. F., Dwyer J. T. Two small surveys, 25 years apart, investigating motivations of dietary choice in 2 groups of vegetarians in the Boston area. J. Am. Diet. Assoc. 1999;99:598-600[Medline]
25.
Koplan J. P., Annest J. L., Layde P. M., Rubin G. L. Nutrient intake and supplementation in the United States (NHANES II). Am. J. Public Health 1986;76:287-289
26. Levy A. S., Schucker R. E. Patterns of nutrient intake among dietary supplement users: attitudinal and behavioral correlates. J. Am. Diet. Assoc. 1987;87:754-760[Medline]
27. Looker A., Sempos C. T., Johnson C., Yetley E. A. Vitamin-mineral supplement use: association with dietary intake and iron status of adults. J. Am. Diet. Assoc. 1988;88:808-814[Medline]
28.
Lyle B. J., Mares-Perlman J. A., Klein B. E. K., Klein R., Greger J. L. Supplement users differ from nonusers in demographic, lifestyle, dietary and health characteristics. J. Nutr. 1998;128:2355-2362
29.
Marwick C. Alterations are ahead at OAM. J. Am. Med. Assoc. 1998;280:1553-1554
30. Medeiros D. M., Bock M. A., Ortiz M., Raab C., Read M., Schutz H. G., Sheehan E. T., Williams D. K. Vitamin and mineral supplementation practices of adults in seven western states. J. Am. Diet. Assoc. 1989;89:383-386[Medline]
31. Mertz W., Abernathy C. O., Olin S. A. In: Risk Assessment of Essential Elements 1994 ILSI Press Washington, D.C.
32. Messina M., Descheemaker K., Erdman J. W., JR Second international symposium on the role of soy in preventing and treating chronic disease. Am. J. Clin. Nutr. 1998;68:1329S-1544S[Medline]
33.
Miller L. G. Herbal medicinals: selected clinical considerations focusing on known or potential drug-herb interactions. Arch. Intern. Med. 1998;158:2200-2211
34.
Mitka M. FDA never promised an herb garden—but sellers and buyers eager to see one grow. J. Am. Med. Assoc. 1998;280:1554-1556
35. Moss A. J., Levy A. S., Kim I., Park Y. K. Use of vitamin and mineral supplement in the United States: current users, type of products, and nutrients. Adv. Data 1989;174:1-19
36. Nestle M. Dietary supplement advertising: policies based on politics, not science. J. Nutr. Educ. 1999;31:278-282
37. for the Women’s Healthy Eating and Living Study GroupNewman V., Rock C. L., Faerber S., Flatt S. W., Wright F. A., Pierce J. P. Dietary supplement use by women at risk for breast cancer recurrence. J. Am. Diet. Assoc. 1998;98:285-292[Medline]
38. Patterson R. E., Neuhouser M. L., White E., Hunt J. R., Kristal A. R. Cancer-related behavior of vitamin supplement users. Cancer Epidemiol. Biomarkers Prev. 1998;7:79-81[Abstract]
39. Patterson R. E., White E., Kristal A. R., Neuhouser M. L., Potter J. D. Vitamin supplements and cancer risk: the epidemiologic evidence. Cancer Causes Control 1997;8:786-802[Medline]
40.
Pfeiffer C. M., Rogers L. M., Bailey L. B., Gregory J. F., III Absorption of folate from fortified cereal-grain products and of supplemental folate consumed with or without food determined by using a dual-label stable-isotope protocol. Am. J. Clin. Nutr. 1997;66:1388-1397
41.
Practice and Policy Guidelines Panel, National Institutes of Health Office of Alternative Medicine Clinical practice guidelines in complementary and alternative medicine. Arch. Fam. Med. 1997;6:149-157
42. Prochaska J. O., Redding C. A., Evers K. E. The transtheoretical model and stage of change. Glanz K. Lewis F. M. Rimer B. K. eds. Health Behavior and Health Education 2nd ed. 1997:60-84 Jossey-Bass Publishers San Francisco, CA.
43. for the Women’s Healthy Eating and Living Study GroupRock C. L., Newman V., Flatt S. W., Faerber S., Wright F. A., Pierce J. P. Nutrient intakes from foods and dietary supplements in women at risk for breast cancer recurrence. Nutr. Cancer 1997;29:133-139[Medline]
44. Sandström B. Toxicity considerations when revising the Nordic nutrition recommendations. J. Nutr. 1998;128:372S-374S[Medline]
45.
Schutz H. G., Read M., Bendel R., Bhalla V. S., Harrill I., Monagle J. E., Sheehan E. T., Standal B. R. Food supplement usage in seven Western states. Am. J. Clin. Nutr. 1982;36:897-901
46. Slesinski M. J., Subar A. F., Kahle L. L. Trends in use of vitamin and mineral supplements in the United States: the 1987 and 1992 National Health Interview Surveys. J. Am. Diet. Assoc. 1995;95:921-923[Medline]
47. Stewart M. L., McDonald J. T., Levy A. S., Schucker R. E., Henderson D. P. Vitamin/mineral supplement use: a telephone survey of adults in the United States. J. Am. Diet. Assoc. 1985;85:1585-1590[Medline]
48.
Subar A. F., Block G. Use of vitamin and mineral supplements: demographics and amounts of nutrients consumed: the 1987 Health Interview Survey. Am. J. Epidemiol. 1990;132:1091-1101
49.
Wetzel M. S., Eisenberg D. M., Kaptchuk T. J. Course involving complementary and alternative medicine at US medical schools. J. Am. Med. Assoc. 1998;280:784-787
50.
Willett W., Sampson L., Bain C., Rosner B., Hennekens C. H., Witschie J., Speizer F. E. Vitamin supplement use among registered nurses. Am. J. Clin. Nutr. 1981;34:1121-1125
51.
Wilt T. J., Ishani A., Stark G., MacDonald R., Lau J., Mulrow C. Saw plalmetto extracts for treatment of benign prostatic hyperplasia. J. Am. Med. Assoc. 1998;280:1604-1609
52.
Winslow L. C., Kroll D. J. Herbs as medicine. Arch. Intern. Med. 1998;158:2192-2199
53. Yates A. A., Schicker S. A., Suitor C. W. Dietary reference intakes: the new basis for recommendations for calcium and related nutrients, B vitamins, and choline. J. Am. Diet. Assoc. 1998;98:699-706[Medline]
This article has been cited by other articles:
|
|
 |
|
  A. C. Patterson and K. D. Stark Direct Determinations of the Fatty Acid Composition of Daily Dietary Intakes Incorporating Nutraceuticals and Functional Food Strategies to Increase n-3 Highly Unsaturated Fatty Acids J. Am. Coll. Nutr., October 1, 2008; 27(5): 538 - 546. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. Sichert-Hellert, G. Wenz, and M. Kersting Vitamin Intakes from Supplements and Fortified Food in German Children and Adolescents: Results from the DONALD Study J. Nutr., May 1, 2006; 136(5): 1329 - 1333. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. A. McNaughton, G. D. Mishra, A. A. Paul, C. J. Prynne, and M. E. J. Wadsworth Supplement Use Is Associated with Health Status and Health-Related Behaviors in the 1946 British Birth Cohort J. Nutr., July 1, 2005; 135(7): 1782 - 1789. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. P. Kelly, D. W. Kaufman, K. Kelley, L. Rosenberg, T. E. Anderson, and A. A. Mitchell Recent Trends in Use of Herbal and Other Natural Products Arch Intern Med, February 14, 2005; 165(3): 281 - 286. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. L. Gray, B. R. Lackey, P. L. Tate, M. B. Riley, and N. D. Camper Mycotoxins in Root Extracts of American and Asian Ginseng Bind Estrogen Receptors {alpha} and {beta} Experimental Biology and Medicine, June 1, 2004; 229(6): 560 - 568. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. S Hampl, C. A. Taylor, and C. S. Johnston Vitamin C Deficiency and Depletion in the United States: The Third National Health and Nutrition Examination Survey, 1988 to 1994 Am J Public Health, May 1, 2004; 94(5): 870 - 875. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Ishihara, T. Sobue, S. Yamamoto, S. Sasaki, and S. Tsugane Demographics, lifestyles, health characteristics, and dietary intake among dietary supplement users in Japan Int. J. Epidemiol., August 1, 2003; 32(4): 546 - 553. [Abstract] [Full Text] [PDF]
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
