| | Position of the American Dietetic Association: Fortification and Nutritional SupplementsAbstract It is the position of the American Dietetic Association (ADA) that the best nutritional strategy for promoting optimal health and reducing the risk of chronic disease is to wisely choose a wide variety of foods. Additional nutrients from fortified foods and/or supplements can help some people meet their nutritional needs as specified by science-based nutrition standards such as the Dietary Reference Intakes. Dietetics professionals are trained to assess dietary adequacy as well as the need for dietary modification. This position paper addresses increasing the nutrient density of foods or diets through fortification or supplementation when diets fail to deliver consistently adequate amounts of vitamins and minerals. The discussion presents points to consider that relate to both public health and individual applications. Many resources may be used to help guide the dietetics professional to determine responsible, evidence-based recommendations relating to nutrient fortification or supplementation.
Position Statement  It is the position of the American Dietetic Association (ADA) that the best nutritional strategy for promoting optimal health and reducing the risk of chronic disease is to wisely choose a wide variety of foods. Additional nutrients from fortified foods and/or supplements can help some people meet their nutritional needs as specified by science-based nutrition standards such as the Dietary Reference Intakes. This position⁎ paper is written for practitioners and policymakers and takes into account the rapid changes in both patterns of fortification and prevalence of use of dietary supplementation that include vitamins and minerals (1). Emerging scientific evidence and new products in the marketplace blur the distinctions between fortified foods, nutrient-containing dietary supplements, dietary supplements with other bioactive ingredients, and drugs. Although limited in scope to vitamins and minerals, the concepts outlined in this paper relate to other nutrients such as proteins and amino acids, fatty acids and other lipids, and dietary fiber. Furthermore, much of the discussion about nutrient supplements applies to dietary supplements containing other bioactive substances. Because this field of research is so active, dietetics professionals will need to adapt the concepts presented in this paper to the evolving understanding of optimal nutrition. Nutrient-Dense Foods Within and Among the Basic Food Groups Before considering fortification and supplementation, one must acknowledge that a balanced variety of nutrient-dense foods eaten in moderation lays the foundation of a health-promoting diet. Nutrient-dense foods are “those foods that provide substantial amounts of vitamins and minerals and relatively few calories” (2). Most of the nutrients that a person consumes should come from a variety of foods and beverages, because they provide vital macronutrients and micronutrients, including water and dietary fiber, as well as pigments and other useful nonnutrient components (3, 4, 5, 6, 7). Diets rich in a variety of foods within and among the basic food groups support nutritional balance and supply nutrients that cannot be added to foods or nutrient supplements at optimal levels. For example, relatively large nutritional requirements for major minerals with distinctive flavors such as magnesium present major formulation challenges for food scientists and supplement makers. In other instances, toxicologic thresholds and the narrow ranges that exist between some trace minerals’ Recommended Dietary Allowances (RDAs) or Adequate Intakes (AIs) and Tolerable Upper Intake Levels (ULs) preclude their addition to foods (eg, copper, selenium) (8). A comparison between the levels of minerals in whole-grain flours and enriched wheat flours illustrates the importance of including basic foods in the diet (3). Despite the useful contributions of fortified foods and nutrient supplements that this paper will define, a diet composed solely of such products does not replace the established or yet-to-be-defined benefits provided by a diet that includes a variety of foods within and among the basic food groups (3, 5). Regulatory Framework for Supplementation and Fortification The essence of the legal definition of a dietary supplement is as follows:
A product (other than tobacco) intended to supplement the diet that bears or contains one or more of the following dietary ingredients: a vitamin or mineral; an herb or other botanical; an amino acid; a dietary substance for use by man to supplement the diet by increasing the total dietary intake; or a concentrate, metabolite, constituent, extract; or combinations of these ingredients. And a product that is intended for ingestion in tablet, capsule, powder, softgel, gelcap, or liquid form; and a product that is not represented for use as a conventional food or as a sole item of a meal or the diet; and a product that is labeled as a dietary supplement (9). Fortification means the addition of nutrients to foods, including beverages, and is used synonymously with “enrichment” (10). Since the 1940s, policymakers at the Food and Drug Administration (FDA) interpreted the food law and determined that fortification in the United States should not be required; rather, nonenriched counterparts to enriched standards of identity still exist (11). However, the FDA does regulate how much of which nutrients must be added to enriched foods, such as infant formula, fortified milk, or foods that contain olestra fat-replacement as a food additive (10, 12). Other than applications defined by the FDA, fortification is voluntary and discretionary (11). In 1980, the FDA codified a nonenforceable Fortification Policy that sets forward principles for the rational addition of nutrients to foods (10). These principles include, in part, adding nutrients to correct dietary insufficiencies; restoring nutrients lost during storage, handling, or processing; and adding 5% of the Daily Reference Value or Reference Daily Intake per 100 kcal for a full range of nutrients (10, 11). Although the FDA cannot force manufacturers to comply with its Fortification Policy, the agency does enforce the truthfulness and accuracy of food labeling of all fortified foods. In 2003, a committee of the Food and Nutrition Board proposed a different rationale for discretionary fortification that will be discussed later in this paper (11). In the United States, the FDA regulates both fortified foods and dietary supplements in accordance with the Federal Food, Drug, and Cosmetic Act (9, 13, 14). Unlike other countries, the United States regulates both categories as foods (15); conventional foods include fortified foods, whereas dietary supplements form a separate category of foods. Despite the potentially vague delineations between foods and dietary supplements, regulations mandate that most packaged conventional foods bear “Nutrition Facts” labeling; dietary supplements also bear nutrition labeling in the form of a “Supplement Facts” panel on their labels (13, 14). Fortification and Supplementation: Modifying the Nutrient Density of the Diet The first two key recommendations for the general population from the Dietary Guidelines for Americans 2005 state, “Consume a variety of nutrient-dense foods and beverages within and among the basic food groups…” and “Meet recommended intakes within energy needs by adopting a balanced eating pattern…” (2). Health statistics indicate that many people in the United States are overweight, yet undernourished (3, 4, 5, 16, 17, 18, 19, 20, 21). These people consume more calories than they need without meeting recommended intakes for several nutrients (3). One way to help these individuals is to improve the nutrient density of their diets. For purposes of this discussion, nutrient density is a relational term and is defined as “the ratio of the amount of a nutrient in foods to the energy provided by these same foods” (22). Therefore, a more vitamin- and mineral-rich diet relative to its caloric content has a higher nutrient density (3). Even when the diet is fully adequate and balanced, nutrients that are added through fortification or supplementation increase the nutrient density of the diet. The balance of this section outlines several points to consider when modifying the nutrient density of the diets of populations and individuals. Food Security Deserves Attention A laudable goal for public health practitioners and policymakers is to have everyone in the population consume the RDA or AI for each nutrient without exceeding its UL (3, 11). However, experts indicate suboptimum nutrient intakes by the US population (3). Specifically, an assessment of available data concluded that low reported intakes of vitamin E, calcium, magnesium, and potassium are of concern for both children and adults; levels of dietary vitamins A and C are also low among adults (3). Subpopulations that consume inadequate levels of vitamins and minerals will be discussed later. Since 1974, data from the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) have shown that increasing the nutrient density of diets, which includes fortified foods, improves the health status of participating at-risk women, infants, and children (23). Sedentary Lifestyles and Low Energy Intakes Present Challenges In the increasingly sedentary American society, people require less energy to maintain a healthy body mass index. To counteract this societal change, the Dietary Guidelines for Americans 2005 advise, “To help manage body weight and prevent gradual, unhealthy body weight gain in adulthood: Engage in approximately 60 minutes of moderate- to vigorous-intensity activity on most days of the week while not exceeding caloric intake requirements” (2). This position is consistent with the Food and Nutrition Board recommendation that individuals get at least 1 hour of physical activity each day to obtain sufficient nutrients from food and drink, and stay in energy balance (24). A complementary approach is to add nutrients to, which increases the average nutrient density of, the standard American diet (4, 5, 25). Optimal Intakes May Be Higher than Previously Recognized Advancements in basic sciences are necessary to further the applied science of nutrition. In its early decades, nutrition research focused on fairly simplistic outcomes that could be demonstrated relatively quickly (26). The expanding knowledge of molecular biology, genetics, and proteomics is setting the stage for explosive growth in the understanding of nutrition (27, 28). As new data are published, more sophisticated theories emerge while old more simplistic one-deficiency-disease-per-nutrient paradigms falter (5, 6, 26, 27, 28, 29). A newer theory, “fetal origins of adult disease,” suggests that maternal nutrition status may affect the genome of the fetus, thereby influencing the offspring’s development and life-long risk of disease (28, 30). Separately, consider the recent theme that indicates that an array of separate diagnoses may share common causes (6, 26, 27, 29, 31). One emerging example points to data published since the Dietary Reference Intakes (DRIs) were issued in 1997 for vitamin D (32): suboptimal vitamin D status may be more widespread than previously thought, because the vitamin’s functions involve more than bone mineral metabolism (3, 18, 26, 31, 33, 34). Researchers speculate that suboptimal serum 25-hydroxyvitamin D-3 may increase the risk of some forms of cancer (18, 26, 31, 33, 34) or exacerbate a variety of autoimmune dysfunctions (31) such as rheumatoid arthritis (35), type 1 diabetes (33, 34), multiple sclerosis (31, 34, 36), and thyroid dysfunction (34). Although it is premature to make recommendations for vitamin D for these conditions, additional research will clarify its role. By improving the nutritional status of the vulnerable but sizeable subpopulations, the prevalence of debilitating diseases may decline and the average health span could increase (18, 26, 27, 33). Fine-tuning a person’s diet based on that individual’s nutritional requirements—which are still being defined through scientific discovery—offers the potential of slowing the onset of multiple chronic diseases by minimizing the effects inflammation and DNA damage or slowing mitochondria’s functional deterioration with aging (6, 26, 27). More research is needed to further our understanding of every facet of “optimal” nutrition. Nutrient Modifications Can Improve Health Status of Subpopulation Groups Some subpopulations are particularly vulnerable to inadequate nutrient intake for a variety of physiological, psychological, and socioeconomic reasons (4, 5, 16, 25, 37). For example, public health measures such as WIC for those in lower-income households show improved iron status among participants (16, 23). Among 2- to 4-year-old children, WIC food packages intend to focus on iron, vitamin E, and potassium (16); WIC-eligible adolescents and women should focus on foods that include calcium, iron, magnesium, potassium, folate, and vitamins A, B-6, C, D, and E (16). Adjusting the density of the diet for one or more nutrients may help protect subpopulations from environmental challenges that they encounter resulting from dietary, occupational, lifestyle, or pharmacologic exposures (25, 27). To illustrate this point, a brief overview of nutrient-drug interactions in the Merck Manual of Diagnosis and Therapy explains that common pharmaceuticals such as oral contraceptives may increase the need for zinc, folic acid, and vitamins B-6 and B-12 (38). Apart from the many environmental influences on nutritional status, conclusions of recent literature reviews identified nutritional needs of several subpopulations that warrant careful attention (3):
•iron—adolescent females and women during childbearing years;
•folic acid—adolescent females and women during childbearing years;
•vitamin B-12—people >50 years old; and
•vitamin D—elderly people, people with heavily pigmented skin, and people exposed to inadequate ultraviolet-B radiation.
Individualized Diets Help People Meet Specific Needs Through appropriate and targeted assessment and coordination with the client’s physician, practitioners can tailor diets to improve health. Medical nutrition therapy and nutrigenomics (how nutrition affects genetic expression) can promote peak performance. Biochemical researchers show clearly how, on a molecular level, dietary or nutrient changes can shift a person’s homeostatic balance toward more health-promoting outcomes (26, 27, 28). Furthermore, diet modifications can aid the expression of favorable genetic phenotypes and help suppress the expression of unfavorable genes (27). For example, upregulating methylation with folic acid and vitamins B-6 and B-12 corrects homocystinemia in genetically susceptible individuals (26, 27, 29). Proper Assessment Needs to Guide Selection and Use of Fortified Foods and Nutrient Supplements When positioned in a suitable context, both conventional and emerging assessment techniques help determine whether a specific formulation or application of a fortified food or nutrient supplement could be beneficial or potentially detrimental (11). A periodic, evidence-based assessment is a responsible, systematic approach to take (7, 39, 40). Special Needs of Individual Clients or Patients Characteristics commonly found in elderly people, such as declining renal function or atrophic gastritis, may influence micronutrient use and clearance (37). This is but one example of the importance of using effective assessment to guide food choices; there are many others. For some people with underlying health conditions, foods and supplements containing specific nutrients could be contraindicated. For instance, individuals who are homozygotic for hemochromatosis should avoid iron-rich foods and supplements (1, 41). Patients undergoing renal dialysis must carefully monitor their mineral status (1, 42). However, researchers still seek definitive answers to questions such as, “Whether and how should smokers modify their intake of antioxidant vitamins?” and “While persons are undergoing radiation therapy, which nutrients should they increase or limit?” Research that further elucidates dietary adequacy must continue (11, 22, 37). Form and Source of the Nutrient Dietetics practitioners should understand and address the differences among various forms and sources of nutrients when counseling clients and patients. This is not to suggest that one form or source of a nutrient is necessarily good or bad, or right or wrong in every situation, but rather that one may function differently from another. Four factors that relate to different facets of bioavailability deserve special consideration (22):
•All forms of a nutrient may not function equivalently. For example, data published, especially since the publication of the 1997 DRIs, indicate that vitamin D-3 delivers far more vitamin D activity than vitamin D-2 (1, 34).
•Research indicates that natural sources of nutrients are not always the most biologically effective (29). Although natural source d-α-tocopherol delivers twice the vitamin E activity as its synthetic dl-α counterpart (1), synthetic folic acid is widely considered more bioavailable than natural sources of folate (43). Regardless, healthful diets that feature a variety of nutrient-dense foods often include nutrients from both natural and synthetic sources.
•Sources of nutrients in a food matrix might perform differently from their isolated counterparts, depending on the nutrient and the dietary context. Calcium citrate malate added to vitamin-C-rich orange juice has been shown to be easily absorbed, but the overall nutritional impact of the fortified juice is obviously not identical to that of milk (1, 3). Separately, vitamin E added to fortified cereals was shown to be more readily available than the same amount taken in capsule form (44). Heme iron is considered more bioavailable than many iron salts (1). On the other hand, foods that contain calcium, phytic acids, tannins, or polyphenols tend to bind or compete for the absorption of non-heme iron, making it less available (1).
•Nutrient balance must be preserved. Some products in the marketplace feature a single added nutrient, whereas others deliver an array of vitamins and minerals. Examples of products that provide relatively high levels of a single nutrient include juice beverages that are fortified with 100% of the Daily Value for vitamin C, and iron supplements. An alternate approach combines many nutrients in a single product, such as fortified ready-to-eat cereals and multivitamin supplements. Since the passage of the Dietary Supplement Health and Education Act of 1994, many product introductions feature small combinations of nutrients that offer structural or functional benefits, such as antioxidant protection. Of course, synergistic and antagonistic nutrient-nutrient interactions—such as the well-documented interaction between zinc and iron—may influence the overall nutrient balance of the diet and the physiologic value of any food or supplement (1). Therefore, with so many facets to consider, practitioners need to assess their clients and patients periodically and to determine whether, and which forms and sources of, nutrients are appropriate. Resources listed in Figure 1, Figure 2 may help guide the assessment process.
Potentially Beneficial or Harmful Interactions With Drugs Use of prescription drugs and polypharmacy increases with age and chronic illness (19). Although interactions with foods and other nutrients have been discussed elsewhere in this paper, one must also consider interactions with drugs or botanicals. Drugs with narrow therapeutic windows, such as warfarin, are particularly sensitive to fluctuations in intakes of nutrients like vitamins E or K. Nutrients and drugs may interact in other ways. For example, corticosteroids have been shown to increase the need for calcium and possibly vitamin D (1). Well known to many, some diuretics used to treat hypertension require compensatory potassium, whereas others are potassium-sparing. By working with knowledgeable dietetics professionals and physicians, individuals can strive to fit their diet and drug regimens around important aspects of their lifestyles instead of forcing their lifestyles to be completely dictated by their medications or dietary restrictions (5). Consumption Patterns That Help Deliver Nutritional Benefits With a few exceptions, most vitamins and minerals are absorbed in the small intestine. Therefore, people should ingest and digest foods and dietary supplements in ways that will maximize the likelihood of absorption. The optimal consumption pattern depends on the nutrient, dose, and form. Nutrient supplements should be consumed in a way that will enhance absorption, typically with food (1, 45). For example, the absorption rate of vitamin E is higher when it is consumed with dietary fat (1, 45). When evidence exists that more thoroughly defines the effective use of a product, it benefits both the manufacturer and consumer to label such information. Nutrient Fortification: Special Aspects When to Support Nutritional Fortification To Comply With Regulations and Government Policy Food fortification can be a cost-efficient way of increasing the nutrient density of a population’s diet (46). As our understanding of vitamin nutrition blossomed in the late 1930s, the US military documented that recruits suffered from clinical nutrient deficiencies. Since 1941, governmental and voluntary programs added nutrients such as thiamin, riboflavin, niacin, and iron to flour and other grain-based products (10, 11). Decades of evidence document that enrichment programs such as these effectively reduce the prevalence of classical nutrient deficiency diseases in populations around the world (46). Beginning in 1998, mandatory levels of folic acid added to enriched grain-based products lowered the prevalence of neural tube defects in the United States and Canada (26, 43, 47, 48). In a separate successful initiative, the US government recognizes that iron-fortified foods largely account for WIC participants’ improved iron status (23). To Address Inadequate Nutrient Intake in Large Segments of the Population Consistent with the key recommendation of the Dietary Guidelines for Americans 2005, fortified foods are nutrient-rich. Therefore, the general population benefits from having a variety of fortified foods available from which to choose. Many breads, cereals, and certain beverages are fortified with vitamins and minerals. Food labels can help guide food selection. Beyond the value of fortified foods to the general public, three categories of subpopulations benefit from food fortification:
•One subpopulation represents those who follow certain dietary regimens for reasons of health or lifestyle. For example, those who consume vegetarian diets can choose fortified plant-based foods such as ready-to-eat cereals or cereal bars to obtain nutrients that naturally come from animal sources, such as vitamins B-12 and D.
•A second category of key subgroups relates to age and stage of the lifecycle (11). Fortified foods can help people meet elevated nutritional needs, such as iron and folic acid for women of childbearing age, or vitamins D and B-12 for older individuals (3, 29, 48). Fortified foods can also help subpopulation groups fill nutritional gaps left by their typical food choices (3). Although it is desirable for adolescent females to consume adequate amounts of calcium-rich foods, the reality is that most fall far short of the goal (1); calcium-fortified foods can help close the gap (16, 18, 20, 49).
•The third category of subpopulations that benefits from fortified foods includes those that involve prevalent diseases or conditions, such as iron-deficiency anemia (1, 16, 23), bone loss (18, 49), or perhaps autoimmune dysfunction (26, 34). From a historic perspective, voluntary fortification began in 1924 for this reason with the iodization of salt to prevent or treat goiter (11), followed in the 1930s with vitamin-D-fortified milk to prevent rickets, which was previously prevalent (11).
Special Considerations Associated With Nutritional Fortification The nutrient profile of a food with discretionary fortification depends on several factors, including the nutritional status of the population that it reaches, which was discussed elsewhere in this paper (11). The Dietary Context For decades, fortified foods fit predictably within a few specific product categories, such as milk, cereals, and juice drinks (3). More recently, nutrients are being added to energy bars, chewing gum, and other new entries in the marketplace (43). As new nutrient-dense, fortified foods become available, dietetics professionals can ask a few questions to determine whether and when such foods would be appropriate for their patients and clients. If a food has not had a long tradition of fortification, does it substitute for another nutrient-rich food, perhaps one that has been fortified through the years? Is the food typically eaten at a certain meal, as a snack, as a meal replacement, or paired with other foods? Does the nutritional profile of the fortified food fit within the context of how the food is commonly eaten? The nutrient profile and labeling of ready-to-eat cereals reflect the fact that they are typically paired with milk. Dietetics professionals must stay mindful of current dietary patterns and continually monitor food labels because nutrient databases do not include the most up-to-date nutrition information for every product, plus the published literature relating to consumption patterns typically lags behind the data collection by several years (43, 50, 51). Technical Feasibility In addition to the dietary context, one must consider the sensory properties of fortified foods. Unlike most nutrient supplements, food is chewed, savored, and enjoyed. Therefore, formulators of fortified foods must overcome many technical challenges of delivering appetizing, good-tasting nutrition (52). If a manufacturer fails to make nutrient additions that are acceptable to consumers, the product will not be successful in the marketplace. Furthermore, fortified foods must maintain their nutritional and sensory qualities throughout the stated shelf-life (ie, the “sell by” or “best if used by” dates printed on packages). To slow oxidative rancidity, antioxidants like vitamin E (sometimes labeled as mixed tocopherols) may be added to keep products fresh as well as to make a nutritional contribution. Implications of Reducing Levels of Nutrient Fortification The rarity of classical nutrient-deficiency diseases in the United States may be the direct result of effective enrichment and fortification practices (11, 43). Regardless, some believe it may be appropriate to scale back enrichment and fortification practices in the United States. In 2003 a committee of the Food and Nutrition Board proposed lowering the Daily Values used for nutritional labeling (11, 53). The committee recommended moving away from the historical application of RDAs to a lower population-weighted calculation of the Estimated Average Requirements (11). Before making such a major policy change, policymakers must analyze the impact on the public’s health, especially for the vulnerable population groups identified earlier in this paper (11, 16, 43). As explained earlier, policymakers must consider new scientific learning that occurs subsequent to the publication of the current DRIs (16). New Technologies Advances in research and development will certainly lead to novel forms of nutrient delivery. For example, if new varieties of folate-rich grain are developed using conventional cross-breeding techniques, would growers and consumers embrace the new dietary source of folate (54)? How would this “biofortification” technology impact the traditional methods of fortification or supplementation? Similarly, recombinant DNA technology may potentially modify the nutritional profile of food crops or remove allergenic properties. How would such changes alter the population’s overall nutritional status? Consumers can now fortify their own foods with nutrients such as iron and vitamin C by sprinkling the contents of single-portion sachets into foods (55). How will newer delivery systems for nutrients impact traditional techniques? Dietetics professionals and policymakers must continuously monitor new developments and evaluate how they may impact current fortification and supplementation practices. Nutrient Supplementation: Special Aspects Although food fortification practices impact public health more broadly, most uses of nutrient supplements address individuals’ specific needs. When to Consider Supporting Nutrient Supplementation To Follow Expert Recommendations for Subpopulations Examples in four types of circumstances illustrate when nutrition experts, professional organizations, or governmental agencies recommend nutrient supplementation. Each circumstance reflects a change in either a person’s typical nutritional needs or his/her eating patterns.
•The first example relates to certain dietary regimens. Experts acknowledge that when adults ingest fewer than 1,600 kcal per day, they have a low probability of getting adequate vitamins and minerals solely from food (3, 25). Physicians overseeing dietary regimens such as modified fasts routinely prescribe vitamin and mineral supplements.
•The second category considers stages during the life cycle. For instance, most protocols for the care of pregnant women include a specially formulated prenatal supplement that contains higher levels of folic acid and iron (1), and oftentimes calcium along with a complement of other vitamins and minerals. Elderly people, having lower rates of nutrient use and often compromised diets, are more at risk for suboptimal nutrition, especially as their caloric intakes decrease to ≤1,500 kcal/day (25).
•The third category addresses using supplements to prevent, treat, and/or manage diseases or other conditions. Some of the many examples that illustrate this point include: (a) supplementation with vitamin D for the prevention of rickets (26, 56) or perhaps some autoimmune disorders (31, 34), (b) electrolyte replacement in the treatment of acute diarrhea (57), (c) the important role of nutrient supplementation in the management of renal dialysis patients (42), and (d) the addition of nutrient supplements to ensure nutrient adequacy for people on low-calorie weight-loss diets (3).
•The fourth type of circumstance reflects an emerging philosophy: to supplement the diet as a public health measure for large subpopulation groups. One such case is in recognition of the importance of adequate folic acid status during the first weeks of pregnancy to prevent neural tube defects. In this instance, the Surgeon General recommends that all women of child-bearing age—whether or not they plan on becoming pregnant—should supplement their diets with folic acid (58).
To Address an Individual’s Nutrition Needs That Are Not Being Met Through Foods Similar sets of circumstances as described in the preceding paragraph determine an individual’s need for nutrient supplementation.
•Dietary regimens that limit variety in food selection represent the first category. To illustrate this point, vegans or people who eliminate all dairy foods from their diets often find it difficult to ingest adequate levels of nutrients such as calcium or vitamin D (1, 7); supplementation may be a logical alternative, especially if they lack exposure to good-quality sunlight (3, 18, 26, 31).
•Certain life stages compose the second category. As the gastrointestinal function of otherwise healthy elderly individuals slows, nutrients from food may not be adequately absorbed or metabolized. Supplementing the diet with nutrients such as crystalline vitamin B-12 may be warranted if serum levels decrease (3, 7, 29, 37, 59).
•The third category is medical nutrition therapy associated with specific diseases or conditions. For example, people with allergies often turn to nutrient supplements because their food choices may be severely restricted. Those with celiac disease typically use supplements to fill the nutritional gaps caused by the malabsorption or the dietary elimination of so many grain-based and other gluten-containing foods; mineral supplementation further addresses anemia and bone health, which is often compromised in patients living with celiac disease (1, 60). Separately, certain genetic diseases or undesirable polymorphisms may be treated through nutritional supplementation at levels higher than ingested from typical diets (27).
Precautions Associated With Nutrient Supplementation For whatever reasons individuals take dietary supplements, they should inform their health care providers and strive for consistency to achieve the intended outcomes. Consistency is especially important when people take pharmaceutical agents that may interact with nutrients being taken as dietary supplements. Need for Careful Product Selection As mentioned earlier, forms of nutrient supplements can vary widely. Supplements are often available in a variety of forms, sources, and potencies. Because regulations require that product labels indicate the specific ingredients and the level of each dose, consumers are able to select the same form of supplements at each purchase. For best results, consumers should buy supplements that deliver consistent quality over time. Although reputable brands may cost more, clients should choose supplements that have recognized quality-control procedures in place. Until the FDA finalizes current good manufacturing practices for dietary supplements (rule proposed in March 2003) (13), the National Sanitation Foundation International (61), the US Pharmacopeia (62), the Australian Therapeutic Goods Administration (63), and the National Nutritional Foods Association (64) are organizations that offer frameworks for supplement quality. Alternatively, manufacturers may pay to have their products tested for l abel compliance and have the results posted on the ConsumerLab.com Web site (65). People with paid subscriptions to the site can learn the names of products that comply with their label claims. Selecting supplements that deliver consistent quality is the first major step toward consistent use of supplements. Importance of Consistent Intake Standardizing the frequency and the method or pattern of consumption contribute to one’s ability to predict the supplement’s overall effect on the body. For example, an individual absorbs less calcium if he or she takes an entire day’s dose of calcium at one time instead of taking the same total amount in divided doses ≤500 mg throughout the day (1). Experts recommend that individuals establish a consistent time for taking nutrient supplements, often with the same meal each day. Regardless, individual response to a nutrient supplement such as vitamin E can vary widely from person to person (44). Consider the Impact of All Sources of Nutrients Caregivers of very young children, and others who include a variety of nutrient-dense foods in their typical food patterns, should periodically review the need to take nutrient supplements (43). In some instances, particularly with fat-soluble vitamins such as preformed vitamin A or trace minerals, people can reach or possibly exceed their ULs (66). In other cases, some physicians recommend that elderly patients take two multivitamin supplements each day as a way to ingest adequate levels of vitamins D and B-12 (66). People in situations such as these may be at particular risk of hypervitaminosis A (66). As stated before, adequate nutritional assessment is vital. Inform Health Care Providers People should report the use of any and all supplements to their health care providers. Because neither physicians nor nurses routinely ask patients about diet or supplement use, dietetics professionals are best suited to ascertain a client’s supplement use at the same time as they learn about his or her dietary patterns and medications. Responding effectively to the information gleaned from the client may prove vital to a successful outcome. Concentrated Sources Because nutrient supplements are concentrated sources of nutrients that typically are not chewed or accompanied by either water or macronutrients, they pose a greater risk than food sources for toxicity, interactions with other nutrients or drugs, and adverse reactions. In some instances, the FDA requires special packaging and labeling to minimize the risk of unintended overdose (10, 13). People should carefully monitor consumption of dietary supplements and keep them stored out of the reach of children. Medical supervision is appropriate when a person consumes fat-soluble vitamins or minerals at levels greater than the RDAs (4, 5). The consumption of pharmacologic doses of nutrients in excess of their RDAs is not discussed here. However, some propose reducing the UL for certain nutrients such as vitamin E (67). Dietetics professionals who recommend dietary supplements must critically evaluate the ever-emerging evidence, particularly the data relating to higher doses. Reporting Adverse Effects If a dietary supplement is suspected of causing a serious adverse event, the FDA encourages health care professionals and consumers to file a voluntary report through the agency’s MedWatch program at 1-800-332-1088, or online at www.fda.gov/medwatch (68). If preferred, a person may complete the Form 3500 and submit it online, via facsimile at 1-800-332-0178, or via mail at: MEDWATCH, The FDA Safety Information and Adverse Event Reporting Program, Food and Drug Administration, 5600 Fishers Lane, Rockville, MD 20852-9787. Use of Fortification and Supplements in the Absence of Established Protocols The need to conduct research to support an evidence-based practice persists in order for us to better comprehend the economic and health implications of altering the nutrient density of foods or diets through fortification and supplementation. Nearly every research paper identifies unanswered questions; some publications lay out particularly insightful recommendations and perspectives (3, 11, 22, 37, 43, 69). With an ever-evolving understanding of nutrition, how should dietetics professionals determine whether, when, and how to put new knowledge into practice? How complete must the evidence be or how overwhelming must the consensus become before an individual embraces a point of view (7, 26, 69, 70)? Although these questions relate to all facets of dietetics, this discussion focuses solely on issues surrounding fortification and nutrient supplements. Dietetics professionals have the training and skills to determine when the evidence warrants integration into their practices. One familiar tenet, “do no harm,” resonates whenever a practitioner approaches the outer limits of her or his comfort zone. When do practitioners place their clients and patients at higher risk by not putting into practice newer ideas that have not achieved universal acceptance (31, 67)? Dr Walter Willett observed that nutrition recommendations evolve slowly, “[Policymakers] say, ’You really need a high level of proof to change the recommendations,’ which is ironic, because they never had a high level of proof to set them” (26, 71). Yes, the quantity and quality of evidence must be convincing; dietetics professionals must critically evaluate all of the relevant evidence before applying it to practice, making sure the recommendations fit within their own professional comfort zone (70). However, instead of waiting for leaders in other professions to state their positions on matters involving diet and nutrition, dietetics professionals have the ability to accept their leadership role, to critically assess all of the evidence, and to act accordingly. Furthermore, dietetics professionals can exert their leadership roles by petitioning organizations and governmental agencies to embrace an evidence-based decision-making philosophy. The ADA and the Commission for Dietetic Registration provide tools that help guide members through their discernment process. Figure 1 summarizes many of the resources offered by the ADA and the Commission for Dietetic Registration. Beyond the information provided by the ADA, professionals can find other useful resources on the Internet and elsewhere to help with the critical evaluation of the massive amount of information that exists on the topics of fortification and supplementation. Several examples are listed in Figure 2. Aspects relating to safety, efficacy, form, level and mode of administration, selection criteria for research subjects, research design, sensitivity and magnitude of results, and stated research hypotheses all deserve special attention. By keeping abreast of the rapidly expanding science and by maintaining questioning yet open minds, discerning dietetics professionals who apply evidence-based techniques to their practices are well positioned to build on previously acquired knowledge and skills to lead the future of dietetics with respect to nutrient fortification and supplementation.
References 1.
1
National Institutes of Health, Office of Dietary Supplements. Available at http://ods.od.nih.gov/index.aspx. Accessed October 29, 2004
2.
2
US Department of Health and Human Services, US Department of Agriculture. Dietary Guidelines for Americans 2005. Available at: http://www.healthierus.gov/dietaryguidelines. Accessed March 3, 2005.
3.
3
US Department of Health and Human Services, US Department of Agriculture. 2005 Dietary Guidelines Advisory Committee Report. Available at: http://www.health.gov/dietaryguidelines/dga2005/report. Accessed August 31, 2004.
4.
4
Fairfield KM
, Fletcher RH
.
Vitamins for chronic disease prevention in adults
(Scientific review)
.
JAMA
. 2002;287:3116–3126
.
MEDLINE |
CrossRef
5.
5
Fletcher RH
, Fairfield KM
.
Vitamins for chronic disease prevention in adults
(Clinical applications)
.
JAMA
. 2002;287:3127–3129
.
MEDLINE |
CrossRef
6.
6
Lopez-Garcia E, Schulze MB, Fung TT, Meigs JB, Rifai N, Manson JE, et al.
Major dietary patterns are related to plasma concentrations of markers of inflammation and endothelial dysfunction
.
Am J Clin Nutr
. 2004;80:1029–1035
.
MEDLINE 7.
7
Willett WC
, Stampfer MJ
.
What vitamins should I be taking, Doctor?
.
N Engl J Med
. 2001;345:1819–1824
.
MEDLINE |
CrossRef
8.
8
Institute of Medicine. Dietary Reference Intakes. Available at: http://www.iom.edu/project.asp?id=4574. Accessed April 22, 2005.
9.
9
Federal Food, Drug and Cosmetic Act. US Code, Title 21, Chapter 9, Subchapter II, Section 321 (ff). 2000 Edition. Available at: http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=browse_usc&docid=Cite:+21USC321. Accessed April 26, 2005.
10.
10
US Food and Drug Administration
.
Code of Federal Regulations, Title 21
(Food and Drug Administration)
.
In: Washington: Office of the Federal Register, National Archives and Records Administration, US Government Printing Office; 2004;
.
11.
11
Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Forti- fication. Washington, DC: The National Academies Press; 2003. Available at: http://books.nap.edu/books/0309091438/html. Accessed November 1, 2004.
12.
12
US Food and Drug Administration
.
Code of Federal Regulations, Title 21
(Food and Drug Administration)
.
Washington, DC: Office of the Federal Register, National Archives and Records Administration, US Government Printing Office; 2004;
.
13.
13
US Food and Drug Administration, Center for Food Safety and Applied Nutrition. Dietary Supplements: Industry Information and Regulation. Available at: http://www.cfsan.fda.gov/∼dms/ds-ind.html. Accessed October 25, 2004.
14.
14
US Food and Drug Administration, Center for Food Safety and Applied Nutrition. Food Labeling and Nutrition: Overview. Available at: http://www.cfsan.fda.gov/label.html. Accessed October 28, 2004.
15.
15
US Food and Drug Administration
.
Code of Federal Regulations, Title 21
(Food and Drug Administration)
.
Washington: Office of the Federal Register, National Archives and Records Administration, US Government Printing Office; 2004;
.
16.
16
Committee to Review the WIC Food Packages, Food and Nutrition Board, Institute of Medicine. Proposed Criteria for Selecting the WIC Food Packages: A Preliminary Report of the Committee to Review the WIC Food Packages. Washington, DC: The National Academies Press; 2004. Available at: http://www.nap.edu/books/0309092981/html/. Accessed April 22, 2005.
17.
17
April 22, 2005. 17. US Department of Health and Human Services, Public Health Service. Healthy People 2010 Progress Review: Nutrition and Overweight. Available at: http://www.healthypeople.gov/data/2010prog/focus19/default.htm. Accessed October 18, 2004.
18.
18
Newmark HL
, Heaney RP
, Lachance PA
.
Should calcium and vitamin D be added to the current enrichment program for cereal-grain products?
.
Am J Clin Nutr
. 2004;80:264–270
.
MEDLINE 19.
19
Centers for Disease Control and Prevention, National Center for Health Statistics. National Health and Nutrition Examination Survey: NHANES Data Briefs. Available at: http://www.cdc.gov/nchs/about/major/nhanes/Databriefs.htm. Accessed April 26, 2005.
20.
20
Nielsen SJ
, Popkin BM
.
Changes in beverage intake between 1977 and 2001
.
Am J Prev Med
. 2004;27:205–210
.
Abstract | Full Text |
Full-Text PDF (103 KB)
|
CrossRef
21.
21
Ogden CL, Fryar CD, Carroll MD, Flegal KM. Mean body weight, height, and body mass index, United States 1960–2002. Department of Health and Human Services Publication No. 2005-1250 04-0467. Available at: http://www.cdc.gov/nchs/data/ad/ad347.pdf. Accessed October 28, 2004.
22.
22
Subcommittee on Interpretation and Uses of Dietary Reference Intakes, Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Food and Nutrition Board, Institute of Medicine
.
Dietary Reference Intakes
(Applications in Dietary Planning)
.
Washington, DC: The National Academies Press; 2003;
.
23.
23
US Department of Agriculture, Food and Nutrition Service. How WIC Helps. Available at: http://www.fns.usda.gov/wic/aboutwic/howwichelps.htm. Accessed April 22, 2005.
24.
24
Panel on Macronutrients, Subcommittees on Upper Reference Levels of Nutrients and Interpretation and Uses of Dietary Reference Intakes, and the Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington, DC: The National Academies Press; 2002. Available at: http://www.nap.edu/openbook/0309085373/html/index.html. Accessed November 1, 2004.
25.
25
Wendland BE
, Greenwood CE
, Weinberg I
, Young KWH
.
Malnutrition in institutionalized seniors
(The iatrogenic component)
.
J Am Geriatr Soc
. 2003;51:85–90
.
MEDLINE |
CrossRef
26.
26
Heaney RP
.
Long-latency deficiency disease
(Insights from calcium and vitamin D)
.
Am J Clin Nutr
. 2003;78:912–919
.
MEDLINE 27.
27
Ames BN
, Elson-Schwab I
, Silver EI
.
High-dose vitamin therapy stimulates variant enzymes with decreased coenzyme binding affinity (increased Km)
(Relevance to genetic disease and polymorphisms)
.
Am J Clin Nutr
. 2002;75:616–658
.
MEDLINE 28.
28
Wu G
, Bazer FW
, Cudd TA
, Meininger CJ
, Spencer TE
.
Maternal nutrition and fetal development
.
J Nutr
. 2004;134:2169–2172
.
MEDLINE 29.
29
Tucker KL
, Olson B
, Bakun P
, Dallal GE
, Selhub J
, Rosenberg IH
.
Breakfast cereal fortified with folic acid, vitamin B-6, and vitamin B-12 increases vitamin concentrations and reduces homocysteine concentrations
(a randomized trial)
.
Am J Clin Nutr
. 2004;79:805–811
.
MEDLINE 30.
30
Gluckman PD
, Hanson MA
.
Living with the past
(Evolution, development, and patterns of disease)
.
Science
. 2004;305:1733–1736
.
CrossRef
31.
31
Vieth R
.
Why the optimal requirement for vitamin D3 is probably much higher than what is officially recommended for adults
.
J Steroid Biochem Mol Biol
. 2004;89–90
.
32.
32
Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Food and Nutrition Board, Institute of Medicine. DRI Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. Washington, DC: The National Academies Press; 1997. Available at: http://books.nap.edu/books/0309063507/html/index.html. Accessed November 1, 2004.
33.
33
Holick MF
.
Vitamin D
(Importance in the prevention of cancers, type 1 diabetes, heart disease, and osteoporosis)
.
Am J Clin Nutr
. 2004;79:362–371
.
MEDLINE 34.
34
Vasquez A
, Manso G
, Cannell J
.
The clinical importance of vitamin D (cholecalciferol)
(A paradigm shift with implications for all healthcare providers)
.
Altern Ther Health Med
. 2004;10:28–36
.
MEDLINE 35.
35
Merlino LA
, Crutis J
, Mikuls TR
, Cerhan JR
, Criswell LA
, Saag KG
.
Vitamin D intake is inversely associated with rheumatoid arthritis
(Results for the Iowa Women’s Health Study)
.
Arthritis Rheum
. 2004;50:72–77
.
MEDLINE |
CrossRef
36.
36
Munger KL, Zhang SM, O’Reilly E, Hernan MA, Olek MJ, Willett WC, et al.
Vitamin D intake and incidence of multiple sclerosis
.
Neurology
. 2004;62:60–65
.
37.
37
Russell RM
.
Factors in aging that effect the bioavailability of nutrients
.
J Nutr.
. 2001;131(suppl 4):S1359–S1361
.
38.
38
Beers MH, Berkow R, eds. The Merck Manual of Diagnosis and Therapy. 17th ed. West Point, PA: Merck Publishing; 1999. Available at: http://www.merck.com/mrkshared/mmanual/section1/chapter1/1d.jsp. Accessed March 16, 2005.
39.
39
Gray GE
, Gray LK
.
Evidence-based medicine
(Applications in dietetic practice)
.
J Am Diet Assoc
. 2002;102:1263–1272
.
Abstract | Full Text |
Full-Text PDF (1118 KB)
|
CrossRef
40.
40
Myers EF
, Pritchett E
, Johnson EQ
.
Evidence-based practice guides vs. protocols
(What’s the difference?)
.
J Am Diet Assoc
. 2000;101:1085–1090
.
Full Text |
Full-Text PDF (472 KB)
|
CrossRef
41.
41
Beutler E
.
Iron absorption in carriers of the C282Y hemochromatosis mutation
.
Am J Clin Nutr
. 2004;80:799–800
.
MEDLINE 42.
42
US National Library of Medicine and the National Institutes of Health. Medical Encyclopedia: Kidney diet—dialysis patients. Available at: http://www.nlm.nih.gov/medlineplus/print/ency/article/007135.htm. Accessed April 26, 2005.
43.
43
Berner LA
, Clydesdale FM
, Douglass JS
.
Fortification contributed greatly to vitamin and mineral intakes in the United States, 1989–1991
.
J Nutr
. 2001;131:2177–2183
.
MEDLINE 44.
44
Leonard SW
, Good CK
, Gugger ET
, Traber MG
.
Vitamin E bioavailability from fortified breakfast cereal is greater than that from encapsulated supplements
.
Am J Clin Nutr
. 2004;79:86–92
.
MEDLINE 45.
45
Jeanes YM
, Hall WL
, Ellard S
, Lee E
, Lodge JK
.
The absorption of vitamin E is influenced by the amount of fat in a meal and the food matrix
.
Br J Nutr
. 2004;92:575–579
.
MEDLINE |
CrossRef
46.
46
The Micronutrient Initiative, The United Nations Children’s Fund (UNICEF). Vitamin and Mineral Deficiency: A Global Progress Report. Available at: http://www.micronutrient.org//reports/reports/Full_e.pdf. Accessed April 22, 2005.
47.
47
Evans MI
, Lurba E
, Landsberger EJ
, O’Brien JE
, Harrison HH
.
Impact of folic acid fortification in the United States
(Markedly diminished high maternal serum alpha-fetoprotein values)
.
Obstet Gynecol
. 2004;103:474–479
.
MEDLINE 48.
48
US Department of Health and Human Services, Public Health Service. Healthy People 2010 Progress Review. Maternal, Infant, and Child Health, 2003. Available at: http://www.healthypeople.gov/data/2010prog/focus16/. Accessed May 24, 2005.
49.
49
US Department of Health and Human Services, Public Health Service. Bone Health and Osteoporosis: A report of the Surgeon General. Available at: http://www.hhs.gov/surgeongeneral/library/bonehealth/docs/exec_summ.pdf. Accessed October 29, 2004.
50.
50
Ahuja JKC
, Omolewa-Tomobi G
, Moshfegh AJ
.
Impact of selected changes in the market place on nutrient intakes
.
J Am Diet Assoc.
. 2004;104(suppl 2):S49
.
51.
51
LeGault L
, Brandt MB
, McCabe N
, Adler C
, Brown A
, Brecher S
.
2000–2001 Food Label and Package Survey
(An update on prevalence of nutrition labeling and claims on processed, packaged foods)
.
J Am Diet Assoc
. 2004;104:952–958
.
Abstract | Full Text |
Full-Text PDF (89 KB)
|
CrossRef
52.
52
Baggs C. A culinary approach to fortified foods. Prepared Foods. Available at: http://www.preparedfoods.com/CDA/ArticleInformation/features/BNP__Features__Item/0,1231,113404,00.html. Accessed September 20, 2004.
53.
53
Council for Responsible Nutrition. IOM Report on Labeling and Values. Available at: http://www.crnusa.org/about_vms_IOMDVs_1203.html. Accessed May 24, 2005.
54.
54
Hossain T
, Rosenberg I
, Selhub J
, Kishore G
, Beachy R
, Schubert K
.
Enhancement of folates in plants through metabolic engineering
.
Proc Natl Acad Sci
. 2004;101:5158–5163
.
MEDLINE |
CrossRef
55.
55
The Sprinkles Group at SickKids. The Hospital for Sick Children, Toronto, ON. Available at: http://www.supplefer.com. Accessed May 18, 2005.
56.
56
Gartner LM
, Greer FR
Section on Breastfeeding and Committee on Nutrition
.
Prevention of rickets and vitamin D deficiency
(New guidelines for Vitamin D intake)
.
Pediatrics
. 2003;111:908–910
.
57.
57
King CK, Glass R, Bresee JS, Duggan C, Centers for Disease Control and Prevention. Managing acute gastroenteritis among children: Oral rehydration, maintenance, and nutritional therapy. MMWR Recomm Rep. 2003;52(RR-16):1–16. Available at: http://www.cdc.gov/mmwr/PDF/RR/RR5216.pdf. Accessed October 25, 2004.
58.
58
US Department of Health and Human Services, Public Health Service. US Surgeon General Announces New Folic Acid Recommendations. January 24, 2005 News Release. Available at: http://www.surgeongeneral.gov/pressreleases/sg01242005a.html/. Accessed March 17, 2005.
59.
59
Seal EC
, Metz J
, Flicker L
, Melny J
.
A randomized, double-blind, placebo-controlled study of oral vitamin B12 supplementation in older patients with subnormal or borderline serum vitamin B12 concentrations
.
J Am Geriatr Soc
. 2002;50:146–151
.
MEDLINE |
CrossRef
60.
60
Celiac Disease Foundation. Available at: http://www.celiac.org/cd-treatment.html. Accessed October 25, 2004.
61.
61
National Sanitation Foundation International. Dietary Supplements Functional Food and Beverages. Available at: http://www.nsf.org/business/dietary_supplements/index.asp?program=DietarySups. Accessed October 29, 2004.
62.
62
US Pharmacopeia. Dietary Supplements. Available at: http://www.usp.org/dietarySupplements. Accessed October 29, 2004.
63.
63
Australian Government. Therapeutic Goods Administration. Available at: http://www.tga.gov.au/index.htm. Accessed October 29, 2004.
64.
64
National Nutritional Foods Association. Available at: http://www.nnfa.org. Accessed October 29, 2004.
65.
65
ConsumerLab.com. Available at: http://www.consumerlab.com. Accessed November 1, 2004.
66.
66
Penniston K
, Tanumihardjo SA
.
Vitamin A in dietary supplements and fortified foods
(Too much of a good thing?)
.
J Am Diet Assoc
. 2003;103:1185–1187
.
Abstract | Full Text |
Full-Text PDF (72 KB)
|
CrossRef
67.
67
Miller ER 3rd, Pastor-Barriuso R, Dalal D, Riemersma RA, Appel LJ, Guallar E. Meta-analysis: High-dosage vitamin E supplementation may increase all-cause mortality. Ann Intern Med. 2005;142:1–11. Available at: http://www.annals.org/cgi/content/full/0000605-200501040-00110v1. Accessed November 13, 2004.
68.
68
US Food and Drug Administration. MedWatch: The FDA Safety Information and Adverse Event Reporting Program. Available at: http://www.fda.gov/medwatch/. Accessed October 25, 2004.
69.
69
Refsum H
.
Is folic acid the answer?
.
Am J Clin Nutr
. 2004;80:241–242
.
MEDLINE 70.
70
US Food and Drug Administration, Center for Food Safety and Applied Nutrition. Guidance for Industry: Substantiation for Dietary Supplement Claims Made Under Section 403(r)(6) of the Federal Food, Drug, and Cosmetic Act—Draft Guidance. Available at: http://www.cfsan.fda.gov/∼dms/dsclmgui.html. Accessed November 1, 2004.
71.
71
Taubes G
.
The soft science of dietary fat
.
Science
. 2001;291:2536–2545
.
MEDLINE |
CrossRef
PII: S0002-8223(05)01034-5 doi:10.1016/j.jada.2005.06.009 © 2005 American Dietetic Association. Published by Elsevier Inc. All rights reserved. | |
|
FULL TEXT
