Dietary Supplements

Dietary Supplements

J Am Diet Assoc. 2005;102:460-470

 

ADA practice papers

Practice papers are evaluative summaries of scientific and/or evidence-based topics. They are meant to provide key opportunities for critical reasoning on timely topics and quality improvement in dietetics practice and to include peer-reviewed perspectives from content practitioners and other experts.

How does a practice topic become a practice paper? Proposals may be generated by any member of the American Dietetic Association via submission of a topic identification proposal, which may be obtained by calling ADA headquarters at 800/899-4835 or by clicking on “Topic Identification Proposals”. The Association Positions Committee oversees the development of practice papers and welcomes proposals from members.

Usual eating patterns of Americans suggest that our diets are frequently inadequate in terms of meeting dietary recommendations for promoting optimal health. Vulnerable groups include elderly people, chronically ill people, vegans, patients with gastrointestinal malabsorption, alcohol-dependent individuals, food-insufficient people, infants, adolescents, pregnant women, and select ethnic populations (1). Although it is the cornerstone of dietetic care, efforts to optimize health through improved dietary selections may not always be sufficient. In addition, for select nutrients, daily requirements may necessitate energy intake above recommended levels to control body weight or intake of food items not acceptable or tolerated by individuals. In these instances, dietary supplementation may be essential to ensure optimal health.

According to National Health Interview Survey estimates, Americans continue to take dietary supplements at an increasing rate, with 33.9% of US adults using a vitamin and mineral supplement in the past 12 months, up from 23.2% in 1987 and 23.7% in 1992 (2). Although consumers of dietary supplements are usually characterized as adult, well-educated females of higher socioeconomic status (3,4), dietary supplement use is expanding to include those of diverse ethnicities (5,6), ages (including young children and adolescents) (7), and education levels as well as both sexes (2). In addition, Americans report consuming supplements not only as insurance for an inadequate diet, but also to prevent or treat disease, increase energy levels, or reduce the risk for infectious illnesses. In 2004, the Multivitamins and Public Health workshop was convened to bring together leading experts from key health organizations to review the literature regarding multivitamin use. This workshop resulted in the publication of a peer-reviewed statement advising all American adults to take a daily multivitamin/mineral supplement (8). The industry-supported Nutrition Business Journal has estimated that the supplement business generated $19.8 billion in 2003 (the nutrition industry as a whole is considered to be a $62 billion industry) (9,10).

Dietetics professionals remain somewhat uncertain when it comes to recommending dietary supplements. Many express concern regarding the potential to overstep their scope of practice from a legal perspective, whereas others are concerned about the lack of adequate training or information regarding the safety and benefits of dietary supplements. With the continued emergence of an expanding dietary supplement market and continued consumer demand for knowledge and information regarding safe and appropriate supplement use, this practice paper was developed to meet the following objectives:
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Define dietary supplements and describe the current regulatory environment.

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Provide guidelines for recommending dietary supplements in practice.

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Provide educational resources regarding the use of dietary supplements.

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Provide legal and ethical perspectives on dietary supplementation.

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Recommend actions that individual dietetics practitioners and the American Dietetic Association (ADA) should consider as our profession expands its role in this area, including steps to empower and educate dietetics professionals.


Definitions and regulatory issues   

Understanding the regulatory definition of dietary supplement as well as the complexity of regulations is central to providing service to clients regarding the appropriate use of supplements. Congress defined the term “dietary supplement” in the Dietary Supplement Health and Education Act (DSHEA) of 1994 (11) as a product taken by mouth that contains a dietary ingredient intended to supplement the diet. The dietary ingredients in these products include vitamins, minerals, herbs or other botanicals, amino acids, and substances such as enzymes, organ tissues, glandular substances, and metabolites. Dietary supplements can also be extracts or concentrates, and are found in forms such as tablets, capsules, softgels, gelcaps, liquids, and powders. They can also be in food forms, such as bars and juices, but if they are, information on their labels must not represent the product as a conventional food or a sole item of a meal or diet. In addition, DSHEA requires that every supplement be labeled clearly as a dietary supplement. Thus, according to DSHEA, dietary supplements are regulated by a specific regulatory category and are enforced by the Center for Food Safety and Applied Nutrition (CFSAN) under the US Food and Drug Administration (FDA), not the Center for Drug Evaluation and Research.

Intended use

The intended use of a product guides what category the product falls under—food, drug, or cosmetic—and how the FDA will regulate it. The FDA has oversight over the labeling and manufacture of dietary supplements, whereas the Federal Trade Commission (FTC) has oversight over advertising. Intended use may be established in a number of ways: (a) claims stated on the product label, in advertising, on the Internet, or in other promotional materials (certain claims may cause a product to be considered a drug, even if the product is marketed as if it were a dietary supplement); (b) consumer perception, which may be established through the product’s reputation (this means asking why the consumer is buying it and what the consumer expects it to do); and (c) ingredients, which may cause a product to be considered a drug because they have a well-known (to the public and industry) therapeutic use.

Claims

Under DSHEA, dietary supplement manufacturers are responsible for determining that the dietary supplements it manufactures or distributes are safe and that any representations or claims made about them are substantiated by adequate evidence to show that they are not false or misleading. There are three broad categories of claims that can be used on dietary supplement labels: health claims, structure/function claims, and nutrient content claims (12). Structure/function claims are the primary mode by which the industry markets dietary supplements. In 2003, the FDA permitted a new type of health claim called qualified health claims. Under this new claim type, scientific evidence supporting a claim is scored and ranked. The FDA uses a process similar to the ADA’s evidence-based rating system to evaluate qualified health claims made regarding dietary supplements (13).

Unlike the FDA, the FTC does not break claims into categories. When evaluating claims about the efficacy of dietary supplements in advertising, the FTC has typically applied a substantiation standard of competent and reliable scientific evidence (14).

Safety concerns related to dietary supplement use

One of the most challenging issues surrounding the use and evaluation of dietary supplements is safety. Safety has continued to be a primary concern of the FDA since the enactment of DSHEA. In 1993, the FDA published a review of illnesses and injuries associated with the use of dietary supplements (15). In addition, the Lancet published an observational study (16) addressing adverse events associated with dietary supplementation, and reports of adverse herb/drug interactions have increased (17-21) for such botanical supplements as St John’s wort, ephedra, and kava. This increase in adverse events is likely in part related to the advent of the FDA’s Adverse Event Reporting Program. Contamination and analytical quality of dietary supplements, primarily botanical products, sold over the counter has also remained a concern (22,23). Dietetics professionals are responsible for reviewing Web-based information, such as information provided by CFSAN, Supplement Watch, or Consumer Lab, to assess any safety issues before recommending dietary supplementation (See Figure 1 for various Web sites).

Figure 1. Resources on dietary supplements. Select reliable resources for evaluating dietary supplement use by patients.

 

Because regulation and enforcement of dietary supplements is continually evolving, dietetics professionals should periodically check the FDA’s Web site to monitor current developments. On November 4, 2004, the FDA announced three major regulatory initiatives designed to further implement DSHEA. These initiatives include: (a) collaboration with federal agencies and other partners to improve the evidentiary base that the FDA uses to make safety and enforcement decisions about dietary ingredients and dietary supplements; (b) implementation of a transparent, systematic, and predictable process to evaluate safety concerns about dietary ingredients and dietary supplements (includes publishing a final rule on current good manufacturing practice requirements for dietary supplements and clarifying what is a new dietary ingredient); and (c) issuance of a guidance document on the amount, type, and quality of evidence a manufacturer should have to substantiate a structure/function claim.


The role of dietetics professionals  

As the use of dietary supplements continues to expand and as labeling regulations become more complex, it becomes even more essential that dietetics professionals position themselves as experts in this area. To do so, dietetics professionals need to show competence in the following:
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identification of dietary supplement use patterns in individual clients;

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evaluation of the proposed benefit of specific dietary supplement products in the context of the individual’s health status;

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evaluation of the safety of products that could potentially interact with over-the-counter or prescribed medications or other dietary supplements and/or food or fortified food products;

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evaluation of the benefits of a product;

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assessment of product quality based on the company’s standards for quality manufacturing and use of good manufacturing practices;

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education of clients regarding “food first” along with the appropriate use of dietary supplementation;

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documentation of dietary supplement use and clinical response including reporting of adverse events that may occur in relation to dietary supplement use;

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monitoring of individual clinical response to dietary supplementation over time;

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critical evaluation of research regarding dietary supplementation;

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education of other health care providers regarding the role of dietary supplementation in health;

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regulatory issues effecting dietary supplement labeling and distribution (eg, structure/function and health claims); and

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legal and ethical issues surrounding the recommending or selling of dietary supplements.

The prophylactic use of dietary supplements in health and disease prevention and management continues to expand. Dietetics professionals need to make a concerted effort to stay abreast of new developments and to arm themselves with reliable resources if they are interested in meeting this challenge. In recent years, ADA-related publications have been developed to both challenge and educate dietetics professionals in this area, including the ADA position paper on food fortification and dietary supplementation (24), guidelines for recommending and selling dietary supplements (25), and the resource guide, A Health Professional’s Guide to Evaluating Dietary Supplements published in conjunction with the American Pharmaceutical Association (26). However, evaluation of dietary supplement use must be a routine part of nutritional care. These competencies should serve as benchmarks for evaluating individual performance.


State of dietetics education   

Dietetics educators are responsible for integrating new content areas into their educational programs to ensure the adequate preparation of future professionals. In 2002, the White House Commission on Complementary and Alternative Medicine Policy recommended that the complementary and alternative medicine (CAM) content, including dietary supplementation, be included in the education and training of all health practitioners (27). Curriculum requirements for dietetics education are guided by the Commission on Accreditation for Dietetics Education. The requirements related to CAM and dietary supplements as stated by the Commission on Accreditation for Dietetics Education are that “graduates will have knowledge of complementary and alternative nutrition and herbal therapies” and that “graduates will have knowledge of dietary supplements” (28). Inclusion of these topics in dietetics curricula has not been formally studied, so it is not possible to evaluate whether or to what extent this topic is currently being addressed in undergraduate education, although there is some concern that dietetics education may be lagging behind usage trends (29).

According to the 2000 Practice Audit conducted by the Commission on Dietetic Registration, 18% of entry-level and 22% of beyond-entry-level practitioners reported that they are currently performing CAM, including dietary supplement evaluation in their practice, and 46% and 42%, respectively, anticipated adding CAM to their practice in the future (30). An ADA task force was charged with and developed general CAM competencies for dietetics practitioners, including recommendations to achieve competence in the area of dietary supplements (29). Specific guidelines for medical education have also been published (31), and something similar would be useful for dietetics educators. Resources and strategies that can be used to integrate these topics into the educational program are needed. It would be useful to develop dietary supplementation educational objectives, sample course content, and a listing of specific learning activities with corresponding knowledge and skill requirements to enhance dietetics training in this area, similar to those suggested by Kauwell (32) in the area of diet-gene interactions.

With curriculum crowding always a concern of faculty, the most practical and realistic options for integrating dietary supplementation content into dietetics education are first to prioritize curricula content and then to integrate the topic into existing courses beginning with basic nutrition and carrying through life cycle, community, therapeutic, and counseling courses. According to a 2004 report by the Centers for Disease Control and Prevention (33), 36% of US adults had used some form of CAM including natural products and diet-based therapies in the past 12 months. If significantly more Americans are using some form of dietary supplements, and if dietetics professionals are to become reasonably positioned to provide recommendations on their use, then it is critical that dietetics education and training provide students with the knowledge base to assist clients with decision making related to dietary supplement use.

The development of additional curriculum requirements for dietetics education in the topic area of dietary supplementation should be based on published competencies for dietetics professionals (29) that state that practitioners should be able to:
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describe the prevalence for dietary supplement use in the US population;

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identify legal, ethical, moral, economic, religious, cultural, and reimbursement issues surrounding dietary supplementation;

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describe the practice implications of DSHEA, FDA structure/function claims, and new and evolving legislation surrounding dietary supplements;

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explain how to read and interpret dietary supplement labels;

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recognize good manufacturing practices;

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identify scientifically sound resources for evaluating the efficacy and safety of dietary supplements;

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delineate the process for reporting adverse events;

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identify the risks, benefits, safe/unsafe practices, and high-risk groups in relation to dietary supplementation;

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associate the most commonly used dietary supplements with their appropriate uses; pharmacokinetics; safe doses; effective biochemical formulations and dosage; and interactions with food, medications, or other dietary supplements;

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demonstrate the ability to access and assess scientifically sound resources;

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articulate legal, ethical, and clinical practice issues;

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practice effective communication with patients and other health care providers regarding dietary supplementation;

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identify patients at risk for deficiencies and/or nutrient insufficiencies;

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articulate strategies for collecting data regarding the individual patient use of dietary supplements; and

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document patient dietary supplement use, education, clinical response, and adverse events.


Developing skills for competency   

It is imperative for any health professional to have the ability to review and critique all published research, particularly in the area of dietary supplementation. Dietetics professionals have numerous opportunities to engage and assist the general public in understanding and interpreting messages communicated by companies that are involved in the retail of dietary supplements. Dietetics professionals should continue efforts to increase public and media awareness of the unique skills and training they have in nutrition science and how these skills allow for effective evaluation of published science regarding dietary supplements. The ADA’s Nutrition and You: Trends 2000 survey indicated that television was the major source of nutrition information for the public (48%), with only 1% of respondents identifying dietitians as a source for nutrition information (34). Dietetics professionals should develop the skills to accurately interpret research and be proactive in communicating research findings to the public, including those specific to dietary supplementation.

Evaluating dietary supplement research

Assuring scientific validity is the responsibility of not only the researcher, but also of dietetics professionals and other health care providers who interpret research findings for their clientele (35). This is necessary to ensure that fraudulence is not perpetuated. Increasingly, health care providers are using the Centre for Evidence-Based Medicine guidelines to assess the scientific merit of research (36). The five steps of evidence-based medicine have been outlined as: (a) asking answerable questions, (b) finding the best evidence, (c) critically appraising the evidence, (d) acting on the evidence, and (e) evaluating performance. Several organizations have provided guidelines for critically appraising the scientific validity of research, including the American Cancer Society (37) and the International Food Information Council (38). These guidelines can be summarized into the following key assessment questions:
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In evaluating the study design, is the study a preliminary study? Was there a control group?

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Was the research population (sample size) large enough (powered amply)? Was the study long enough?

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Was there objective reporting of information? Were the findings supported by other published research—why or why not?

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Were both efficacy and safety shown?

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Were the study findings put into a context that makes the results relevant to clinical practice?

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Was the research peer-reviewed before publication?

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Was the study performed with animals or human beings?

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What was the funding source?

In addition, the Agency for Healthcare Research and Quality has published evidence reports and technology assessments that use systematic review methodology to evaluate the quality and extent of scientific evidence for the use of select dietary supplements (See Figure 1 for Web site).

Scientific studies regarding dietary supplementation can be categorized as follows: clinical trials, animal studies, in vitro laboratory studies, and other. The clinical trial design hierarchy is ordered as follows (ranked from highest order downward):
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prospective, randomized, double-blind, placebo-controlled clinical trial with crossover;

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prospective, randomized, double-blind clinical trial;

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single-blind clinical trial;

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open-label clinical trial;

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retrospective epidemiological study; and

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other types (including meta-analyses) of consumer or patient-based, interview-type studies.

Although few dietetics professionals work in strictly clinical research, it is important for the profession to have an understanding of clinical trial design, types of statistics used in research, and how to examine whether investigators have disclosed (or not disclosed) potential conflicts of interest. The research should be hypothesis driven, with clear-cut stated objectives regarding the safety and efficacy parameters being examined. Resources for information related to research design can be found, including publications of ADA, the FDA, the International Food Information Council, the United States Pharmacopeia, and elsewhere (39-43). It is also important to understand that in the area of traditional botanical use, randomized, controlled clinical trials may not be available, yet years of traditional use may support the efficacy and safety of the product. Dietetics professionals assessing the efficacy and safety of such products should consider consulting traditional healers for additional information and should also review the available literature on the supplement’s long-term safety and/or efficacy.

Similar to the pharmaceutical and food industries, many dietary supplement companies directly sponsor clinical research on their finished products or individual ingredients within products. This research ranges from in vitro laboratory studies to full-fledged, prospective, randomized, double-blind, placebo-controlled clinical trials. Dietary supplement manufacturers may also sponsor research to further develop intellectual property and to obtain safety and efficacy data on their products.

The consistent and accurate dissemination of information from nutrition scientists, researchers, and other health professionals is an important step in the chain of communicating interpretation and advice to the consumer with respect to dietary supplements. There are many sources of information and misinformation. Nutrition misinformation can potentially be disseminated by the media, Internet sources, industry, or even e-mail list-serves. Any assessment of scientific integrity of the information should begin with a comparison of the original research article with the disseminated information. When reviewing the original study, the dietetics professional should consider the strength of diet-outcome association, brand name, and chemical form of the specific supplement under study; any dose-response relationship; temporal aspects of the association; consistency of association either over time or in comparison with other published research; specificity of association as well as biological plausibility; and full disclosure of any conflict of interest (44-46).

Identifying quality continuing professional education opportunities

Reliable continuing professional education resources specific to dietary supplements are widely available (see Figure 1). Integration of these resources into dietetics professionals’ educational portfolios should significantly enhance competence in this area. Dietetics professionals should review educational programs or resources cautiously and consider the source (eg, organization, individual, industry), qualifications of authors and editors, completeness of the data presented, and timeliness of the information. It is advisable to review more than one source when evaluating the efficacy and safety of select dietary supplements; consistency across resources generally indicates a more scientifically sound assessment. Given the rapidly evolving science in this area, dietetics professionals should select resources that are up-to-date and supplement with frequent scientific database reviews to determine whether new information has been published (eg, PubMed, Medline, evidence-based medicine reviews).

Peer-reviewed journal articles have been published to address both the quality and the usefulness of dietary supplement reference books as well as published reports and articles, and should be referred to when selecting professional reference materials (47-49). Select professional journals that include articles related to curriculum development and evaluation. These publications can be a useful resource when attempting to assess the current state of knowledge or developing new resources and/or coursework in this area.

Dietary supplement education programs should be presented in a nonbiased manner. The evidence for and against both the known safety and the efficacy of a specific, single-nutrient supplement (eg, vitamin C) or multi-ingredient product (eg, multivitamin/mineral supplement) should also be covered. The evidence or balanced discussions should include in vitro data, animal studies, and all forms of human clinical trials. Education regarding how to identify quality-minded manufacturers and quality parameters in the manufacture and labeling of dietary supplements should also be included in the educational content.


Practice guidelines   

The challenge to dietetics professionals lies in the implementation of knowledge through practice and marketing efforts as well as alliances with other health care professionals and possibly industry. Once the professional has completed the foundational education process and then acquires skills, tools, and the necessary reference materials to provide quality care, the next challenge is to bring this knowledge to action through client-provider interactions. A starting point should be evaluation of dietary supplement use. It is clear that dietetics professionals can and should evaluate and recommend Dietary Reference Intakes nutrients in dietary supplements in the context of a well-balanced diet (50). However, this is less clear for other components that meet the definition of dietary supplements and for which Dietary Reference Intake levels have not been established, such as botanicals or hormonals. This issue has not been resolved either intellectually or legally. Some would argue that to ignore botanical use among clients, particularly if the dietetics professional is knowledgeable of potential harm, would be considered unethical. Others would argue that it is important to understand a client’s use of botanicals because many of the health conditions for which they are using such supplements are also responsive to dietary modifications or nonherbal nutrient supplementation (ie, heart health, bone density, immune support, menopausal symptoms). Others see botanical use as a less evidence-based area of professional practice, or recognize that they are not adequately trained to provide such service and refer to other health care providers with expertise in botanical medicine to serve as resources for clients (ie, licensed acupuncturists) rather than risk potential legal ramifications. Regardless of dietetics professionals’ personal views, it is necessary to document all supplements that a patient/client is taking, because select supplements have been shown to interact with medications.


Ethical issues   

Controversy continues to exist and evidence-based practice information regarding dietary supplementation is in its infancy, thus any discussion of dietary supplements is not complete without addressing the ethical issues. Lack of solid scientific data coupled with potential conflicts of interest when dietetics professionals become involved in selling dietary supplements are both areas of concern. The ADA’s guidelines for recommending and selling dietary supplements have been published elsewhere (25), but briefly, they include the importance of patient assessment, literature review, product safety evaluation, keeping the client’s best interests foremost, reporting adverse reactions, accountability for competence, client education, financial disclosure, and truthful advertising per the ADA’s Code of Ethics (51).

A sample case study is provided below to illustrate the process of dietary supplementation evaluation and recommendation for dietetics professionals. Putting this process into practice is complex and requires individualization. Each of us would likely approach this case in a slightly different way; however, providing a case example is important in demonstrating the complexity and possibilities as dietetics professionals gain expertise and comfort in this dynamic area of dietetic practice.

Case study

The supplement assessment was developed using the “Evaluating Dietary Supplement Use” guidelines (Figure 2).Dietary supplementation assessment should be completed in the context of a more comprehensive nutritional status assessment including a review of medical history, a diet history, anthropometric measurements, biochemical evaluation, and nutrition physical examination. In the following case, “S” is information reported by the patient; “O” is objective reference information about the dietary supplement from peer-reviewed sources; “A” is assessment of the rationale and efficacy of the specific supplement in the context of the specific case described; and “P” is the plan for supplementation, follow-up, and communication with other health care providers.

Figure 2. Evaluating dietary supplement use. Step-wise progression for evaluation of dietary supplementation in individual patients. Four-step process: ASK, EVALUATE, EDUCATE, and DOCUMENT.

 

The following is an example of an assessment of dietary supplement products using select cited literature and resources (seeFigure 1).

Mrs. Smith is a 52-year-old, overweight, perimenopausal white woman who has been diagnosed with osteoarthritis and referred for weight loss. She has no other medical problems. Diet history revealed a low intake of calcium sources. She is experiencing hot flashes and night sweats and has occasional bouts of indigestion and sleeplessness. The only medications she takes are over-the-counter (aspirin) and prescription nonsteroidal anti-inflammatory drugs (NSAIDs) for knee pain, but they have not seemed to help. She has made the decision not to take hormone replacement therapy because of her family history of breast cancer. During her first visit, she mentions that some of her friends are taking glucosamine and have no more knee pain. She has also read in a magazine that black cohosh can cure hot flashes. And the clerk at the health food kiosk in the mall told her that kava might help her sleep. She would like advice on these dietary supplements.

Glucosamine
S

The patient reports that the product label claims that glucosamine relieves knee-joint pain.

O

Review of evidence suggests that glucosamine is an amino monosaccharide derived from glucose metabolism that plays a role in cartilage formation. There are no reported serious side effects in short-term (3 years) studies. More mild side effects may include upset stomach, drowsiness, and headache. No significant drug/nutrient interactions have been described. Preliminary evidence suggests that it may reduce symptoms of osteoarthritis as compared with a placebo, and glucosamine is at least as effective as NSAIDs. Some but not all studies suggest combining glucosamine with chondroitin to achieve greater pain relief. There is a potential to develop an allergic reaction to glucosamine because it is derived from shellfish, but no cases have been reported to date despite widespread use of this supplement. Problems have been reported with standardization of products containing chondroitin. Glucosamine may be taken for 4 to 8 weeks before any clinical benefit is seen. This dietary supplement is generally most effective in earlier stages of the disease, and continuous use is recommended for therapeutic benefit. There are no known food sources of glucosamine. The recommended dosage is 500 mg three times daily (52,53).

A

In assessing the efficacy of the supplement, it is important to evaluate the validity of claims associated with the product. Peer-reviewed evidence for the use of glucosamine to reduce the symptoms of osteoarthritis does exists, although findings are inconsistent (54). A trial by the National Center of Complementary and Alternative Medicine has recently completed recruiting subjects, and results for this randomized clinical trial will be available by 2006 (see Web site listed in Figure 1). Thus, the current evidence suggests that a potential benefit exists with little risk, even at doses of 1,500 mg/day in nondiabetic, nonpregnant adults. The patient will be queried regarding evidence for shellfish allergy because the product should not be used by those at risk of or reporting shellfish allergy.

P

Because the available evidence from randomized, controlled clinical trials supports the use for improving symptoms of osteoarthritis, especially of the knee, the patient is advised to continue use of glucosamine (55). Compliance, tolerance, and clinical response using the suggested dose will be monitored monthly. The patient is advised to select a product that has been cleared by ConsumerLab (Web site listed in Figure 1) because product potency can be highly variable. The dietetics professional should document recommendations in detail in the patient’s medical record and should inform other health care providers of supplement use as indicated.

Black cohosh
S

The patient began using black cohosh to relieve adverse menopausal symptoms, including hot flashes.

O

Review of peer-reviewed evidence suggests that black cohosh is generally safe, although there have been reports of stomach discomfort, headaches, and weight problems. The specific mechanism of action is inadequately described (56).

A

A review of current claims for validity indicates that the preliminary evidence is encouraging. The National Institutes of Health is currently funding studies. Earlier peer-reviewed evidence has shown inconsistent results. The American College of Gynecology states that black cohosh supplementation may be helpful in short-term use (6 months or less) for vasomotor symptoms (eg, sweating, palpitations) of menopause (56). Few adverse events have been reported; however, long-term safety data are not available. One study of 5 years’ duration showed a small but significant increase in the risk of certain diseases. Earlier evidence suggested that black cohosh had estrogenic activity, which could impact breast or uterine tissue, but more recent studies have refuted this assumption. This supplement should not be used by women who are pregnant or those with breast cancer until estrogenic effects are better understood. No food sources for black cohosh are available. The recommended dose for efficacy in reducing menopausal symptoms is 20 mg/day, providing 2 mg triterpene glycoside, up to 80 mg/day, providing 4 to 8 mg triterpene glycoside (57,58).

P

Given that recent data suggest that short-term use is safe, but long-term studies are limited, the patient will be monitored monthly for possible adverse effects associated with long-term use. In addition, the patient will be monitored for unintentional changes in body weight or reports of gastrointestinal discomfort. The patient will be educated regarding selection of quality products, including the need to use products containing standardized extract (triterpene glycosides) or brands previously tested in clinical trials (eg, RemiFemin Menopause [GlaxoSmithKline, Middlesex, England], Enzymatic Therapies [Green Bay, WI], or Phytopharmica [Green Bay, WI]). Complete documentation of product use, patient education, and expected compliance should be made in the patient’s medical record. Health care providers should be informed as appropriate.

Kava
S

The patient reports that she is taking kava to promote sleep and relaxation.

O

Review of the peer-reviewed evidence indicates that there is a long history of traditional use among Pacific Islanders. Reports also indicate that there is a possible induction of abnormal liver function or damage that is often irreversible in select people using kava supplementation; deaths have been reported. To this end, the FDA released a warning to consumers in March 2002 (59). Kava has been banned in Canada, Germany, Switzerland, South Africa, and Singapore. Kava has also been shown to interact with antianxiety medications, alcohol, barbiturates, and levodopa. The mechanism of biological action is not fully understood. Kava may act as a monoamine oxidase inhibitor. Reported side effects have included rash; tremors; muscle spasms; liver toxicity; and discolored skin, hair, and nails (60).

A

In developing a recommendation for this patient in regard to kava use, it is clear that patients with liver disease or Parkinson disease should not use kava-containing supplements. There is a need for more information regarding the safety of kava supplementation in healthy individuals. There is limited evidence that kava may reduce anxiety in nonpsychotic anxiety disorders, but more research is needed. Randomized clinical trials are lacking regarding the sedative effect for sleep. Kava is generally used at a dose of 300 mg/day. Clearly, kava supplementation should be discouraged in pregnancy (or in women with the potential to become pregnant), and patients taking kava should not combine its use with alcohol or other drugs. This dietary supplement should not be taken without medical advice, and close medical follow-up is necessary to evaluate hepatic function. Kava has also been shown to reduce motor reflexes and therefore cannot be used while driving or operating motorized equipment (60).

P

Given that kava is potentially hazardous and that there is concern about hepatotoxicity, which resulted in its removal from the markets in many countries because of safety concerns, kava supplementation is not recommended. The patient will be informed of the FDA-issued warning about usage. The dietetics professional suggests other means to induce sleep (eg, warm milk before bedtime, avoidance of alcohol, relaxation techniques) and refers the patient to other health care providers for assistance in improving sleep.

Calcium
S

The patient is interested in taking calcium to promote increased bone density because she is a perimenopausal woman. She also understands that calcium may promote weight loss, and she wants to lose weight.

O

Review of the currently available peer-reviewed evidence suggests that calcium supplementation has been shown to be safe. The tolerable upper limit for calcium is 2,500 mg/day (50). However, there are some concerns, including the concern that calcium supplementation may lead to constipation. The patient’s diet should be evaluated to estimate daily dietary and supplemental calcium intake. The goal is to achieve a daily intake of 1,500 mg/day total calcium, the level of intake recommended to optimize bone mineral density. Recent studies suggest that calcium supplementation does not significantly increase weight loss or body fat loss during a randomized, double-blind, placebo-controlled weight loss intervention among adult women (61), although greater dietary calcium intake is likely beneficial in weight control (62). The results of the Women’s Health Trial should be available in 2006 to further answer this important scientific question regarding optimal calcium intake for bone health and weight control. The exact mechanisms by which dietary calcium may induce weight loss are not known, but are postulated to be related to hormone regulation.

A

Because the patient is perimenopausal and reports a low activity level, 500 to 1,000 mg supplemental calcium is recommended each day to complement dietary intake of calcium to achieve the recommended intake level for optimizing bone health.

P

The patient is advised to increase intake of low-fat, calcium-rich foods daily. In addition, to promote weight control the patient is advised to consume a minimum of five servings of vegetables and fruits each day to replace other energy-dense foods in an effort to promote weight control. The dietetics professional is to inform other health care providers of the nutritional care plan.


Summary   

Efforts to improve the eating habits of Americans must continue in light of the growing obesity epidemic. When dietary intakes are insufficient to optimize health and when scientific evidence exists supporting dietary supplementation to improve health, dietetics professionals must have an opportunity to provide this information to consumers. Dietary assessment can no longer be confined to evaluation of food intake. It must also include a thorough and accurate evaluation of dietary supplement use (or lack thereof).

Dietetics professionals, with their comprehensive training in biological sciences, diet, and behavior, are uniquely positioned to lead in this expanding area of health care. The foundation has been laid in recent years to take on this challenge with confidence and competence. Although professional continuing education programs are available and evidence-based databases exist, without an individual effort to develop this expertise, quality of care can and may be compromised. The World Health Organization has recently recommended that qualification and registration systems be developed to promote consumer safety in the area of dietary supplementation (17).

With appropriate and thorough training, an understanding of the ethical and legal issues as addressed at the Association level, and the perspectives for practice provided here, dietetics professionals are well positioned to lead health care practice in this pivotal area. In addition, the resources, references, and assessment tools should provide further support for taking knowledge into practice. Dietetics professionals have the responsibility to serve as the resource for consumers making decisions regarding dietary supplementation.

Recognition is given to the following people for their contributions in developing this practice paper. Author/editor: Cynthia A. Thomson, PhD, RD, FADA (University of Arizona, Tucson). Contributing authors/content practitioners: Nancy Cotugna, DrPH, RD (University of Delaware, Newark); Douglas S. Kalman, MS, RD, FACN (Miami Research Associates, Miami, FL); Leila G. Saldanha, PhD, RD, FACN (Scientific Consultant, Alexandria, VA). Reviewers: Dietetic Technicians in Practice dietetics practice group (Denise Elmore, DTR, University of Texas MD Anderson Cancer Center, Houston); Jessica Donze Black, MPH, RD (ADA Government Relations, Washington, DC); Patricia Giblin Wolman, EdD, RD (Winthrop University, Rock Hill, SC); Leslie K. Kay, MS, RD (University of California, Irvine); Adam Perlman, MD, MPH (Institute for Complementary and Alternative Medicine, University of Medicine and Dentistry of New Jersey, Newark); Tamara Schryver, MS, RD (University of Minnesota, St Paul); Riva Touger-Decker, PhD, RD (University of Medicine and Dentistry of New Jersey, Newark); Gretchen K. Vannice, MS, RD (Nordic Naturals, Inc, Watsonville, CA). APC Workgroup: Mary P. Fuhrman, MS, RD (chair) and Idamarie Laquatra, PhD, RD.


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