Dietitians use and recommend dietary supplements: report of a survey

Global hotspots and trends of nutritional supplements in sport and exercise from 2000 to 2024: a bibliometric analysis

BACKGROUND

Nutritional supplements for sports and exercise (NSSE) can facilitate the exogenous replenishment of the body. This study provides the first extensive overview of NSSE research through bibliometric and visual analyses.

METHODS

We searched the Web of Science Core Collection database for literature related to "NSSE" from 1st January 2000 to 8th March 2024. A total of 1744 articles were included. CiteSpace, VOSviewer, and Bibliometrix R package software were used to analyze the data.

RESULTS

Research in the NSSE can be divided into steady growth, exponential growth, fluctuating stage, and surge stages. The United States is the most active country in this field. In recent years, the leading countries have been Croatia, Colombia, Slovenia, Chile, Egypt, China, and Thailand. The Australian Institute of Sports is the top research institution in terms of number of publications. Burke, LM from Australia published the most articles. Research in this area has primarily been published in Nutrients in Switzerland. The study population mainly consisted of men, and postmenopausal women were the main focus of the female group. Coronary heart and cardiovascular diseases continue to dominate research.

CONCLUSION

Research on the NSSE is developing rapidly, with an annual growth trend. Insulin resistance, sports nutrition, inflammation, alpha-linolenic acid, limb strength performance, female sex, and gut microbiota are the focus of the current research and trends for future research. Future research should focus on improving the scientific training system for athletes and quality of training and life for the general public.

Quantity, Duration, Adherence, and Reasons for Dietary Supplement Use among Adults: Results from NHANES 2011-2018

Dietary supplement use is common among US adults. We aimed to investigate the quantity, duration, adherence, and reasons for supplement use in individuals who take supplements. Data from 2011 to 2018 from the National Health and Nutrition Examination Survey (NHANES) dataset were analyzed. Four cycles of data were combined to estimate these outcomes. Results are presented as overall group and by subgroups. All analyses were weighted to be nationally representative. The Taylor Series Linearization approach was used to generate variance estimates. A total of 12,529 participants were included. Over 70% of these individuals reported taking more than one unit of dietary supplements daily. Notably, approximately 40% had been taking supplements for more than five years and about 67% were highly adherent to at least one supplement. However, only 26.9% of these supplements were taken following a doctor's recommendation. The primary reasons for dietary supplements intake included improving overall health (37.2%), maintaining health (34.7%), bone health (21.4%), and diet supplementation (20.3%). Our findings indicate that most participants proactively used multiple dietary supplements focused on self-managed health and prevention, with substantial dedication to long-term use and high adherence. Healthcare professionals should play a more active role in guiding such behaviors to optimize the health outcomes of dietary supplement users across the United States.

Perspectives and practices of nutritionists on dietary supplements for elite soccer teams: a cross-sectional survey study

Introduction and objectives

Dietary supplements are part of the nutritional strategies frequently applied in sports performance support. With growing research on this subject and high demand from athletes, nutritionists need to keep up to date with the latest evidence and utility of dietary supplements, particularly in real-world contexts. As information about the use of dietary supplements among elite soccer players is still scarce, this work aimed to know how nutritionists working with elite soccer teams perceive and use these substances in their daily practice.

Methods

A questionnaire previously used to describe nutritionists' beliefs and attitudes regarding the use of dietary supplements in a clinical context was adapted for this study. The online questionnaire was addressed to nutritionists working with elite soccer teams from six European Leagues and Brazil, between November 2022 and February 2023.

Results

Overall, the participants considered themselves well-trained (76.9%), knowledgeable (95.4%), and interested in dietary supplements (95.4%). The majority (70.8%) of the participants agreed or strongly agreed to recommend dietary supplements to soccer players. Personal usage of dietary supplements was associated with recommending supplements (p < 0.001), but no relationships were found with years of experience and academic level.

Discussion

Nutritionists working with elite soccer players consider the use of dietary supplements for performance-enhancement purposes and not only to compensate for nutritional deficits, which might contribute to their higher interest, training and perceived knowledge about this topic. Participants recognize players' interest in dietary supplements, and are mindful of the safety and efficacy of these products. The present study suggests that nutritionists working with elite soccer teams are among the highest prescribers of dietary supplements, although personal usage is lower than that of nutritionists working in a clinical context.

Autopercepción y uso de suplementos nutricionales en usuarios de gimnasios

La insatisfacción con la imagen corporal puede desencadenar preocupación excesiva por la estética conduciendo a una utilización indiscriminada de suplementos nutricionales. Por ello, el objetivo de este estudio fue investigar la relación entre percepción y conformidad de imagen corporal al uso de suplementos nutricionales en usuarios regulares de gimnasios de la región del Biobío, Chile. La investigación corresponde a un estudio analítico transversal realizado en el segundo semestre del año 2018, en el que participaron 262 personas mayores de 18 años. Se observó una asociación estadísticamente significativa entre el uso de suplementos nutricionales y la percepción de la imagen corporal (OR 0,58, IC95%0,34–0,98; p=0,045), y entre el uso de suplementos nutricionales y la conformidad con la imagen corporal (OR 0,43, IC95%0,25–0,75; p=0,003). En conclusión, a mayor disconformidad con la imagen corporal o la presencia de una percepción alterada de ésta, mayor es la probabilidad de consumir suplementos nutricionales.

Interassociation Consensus Statement on Sports Nutrition Models for the Provision of Nutrition Services From Registered Dietitian Nutritionists in Collegiate Athletics

Collegiate athletic programs are increasingly adding nutrition services to interdisciplinary sports medicine and sports performance departments in response to scientific evidence highlighting nutrition's integral role in supporting athletic performance and overall health. Registered Dietitian Nutritionists (RDNs) specializing in sports dietetics (ie, sports RDNs) and credentialed Board-certified Specialists in Sports Dietetics (CSSDs) are the preferred nutrition service providers for these programs. Their extensive training and proficiency in medical nutrition therapy, education and behavioral counseling, food-service management, exercise physiology, physical performance, and administration, as defined by the "Standards of Practice and "Standards of Professional Performance" for Registered Dietitian Nutritionists in Sports Nutrition and Human Performance," make these practitioners uniquely qualified to deliver the breadth of care required in the collegiate setting. Therefore, this document, guided by a multidisciplinary panel, introduces 4 sports nutrition models through which any collegiate athletic program can deliver sports RDN-directed nutrition services. In each model, the most effective staffing and scope of service are indicated and reviewed. In addition, recommended organizational structures for sports RDNs are provided that best support the delivery of the model's nutrition services in a variety of collegiate athletic programs and organizational settings. Lastly, future research initiatives and nutrition interventions to help improve the standard of care through these sport nutrition models are explored.

Vitamin, Mineral, and Multivitamin Supplementation to Prevent Cardiovascular Disease and Cancer: US Preventive Services Task Force Recommendation Statement

Importance

According to National Health and Nutrition Examination Survey data, 52% of surveyed US adults reported using at least 1 dietary supplement in the prior 30 days and 31% reported using a multivitamin-mineral supplement. The most commonly cited reason for using supplements is for overall health and wellness and to fill nutrient gaps in the diet. Cardiovascular disease and cancer are the 2 leading causes of death and combined account for approximately half of all deaths in the US annually. Inflammation and oxidative stress have been shown to have a role in both cardiovascular disease and cancer, and dietary supplements may have anti-inflammatory and antioxidative effects.

Objective

To update its 2014 recommendation, the US Preventive Services Task Force (USPSTF) commissioned a review of the evidence on the efficacy of supplementation with single nutrients, functionally related nutrient pairs, or multivitamins for reducing the risk of cardiovascular disease, cancer, and mortality in the general adult population, as well as the harms of supplementation.

Population

Community-dwelling, nonpregnant adults.

Evidence Assessment

The USPSTF concludes with moderate certainty that the harms of beta carotene supplementation outweigh the benefits for the prevention of cardiovascular disease or cancer. The USPSTF also concludes with moderate certainty that there is no net benefit of supplementation with vitamin E for the prevention of cardiovascular disease or cancer. The USPSTF concludes that the evidence is insufficient to determine the balance of benefits and harms of supplementation with multivitamins for the prevention of cardiovascular disease or cancer. Evidence is lacking and the balance of benefits and harms cannot be determined. The USPSTF concludes that the evidence is insufficient to determine the balance of benefits and harms of supplementation with single or paired nutrients (other than beta carotene and vitamin E) for the prevention of cardiovascular disease or cancer. Evidence is lacking and the balance of benefits and harms cannot be determined.

Recommendation

The USPSTF recommends against the use of beta carotene or vitamin E supplements for the prevention of cardiovascular disease or cancer. (D recommendation) The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of the use of multivitamin supplements for the prevention of cardiovascular disease or cancer. (I statement) The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of the use of single- or paired-nutrient supplements (other than beta carotene and vitamin E) for the prevention of cardiovascular disease or cancer. (I statement).

Knowledge, use and practices of licensed dietitians related to dietary supplements in Lebanon

OBJECTIVE

To evaluate Lebanese licensed dietitians' knowledge, prevalence of use and recommendation of dietary supplements (DS), and their associated factors.

DESIGN

Cross-sectional survey.

SETTING

Dietitians across Lebanon were contacted through the telephone and were asked to participate in the study. An online self-administered questionnaire was designed and sent to dietitians either by email or by WhatsApp, between 4 March and 4 May 2020.

PARTICIPANTS

This study included 319 dietitians randomly selected from the dietitians' list that was provided by the Lebanese Ministry of Public Health.

RESULTS

Around 75 % of dietitians had a knowledge score above 50 %. Overall, 73·7 % of them have used DS and 46·1 % have recommended them. Higher knowledge score was associated with less years of experience, using scientific articles as source of information on DS, and participating in research. Resorting to pharmacists was significantly associated with both nutrient supplements (NS) and herbal supplements (HS) use, whereas referring to health food stores was associated with HS use only. NS recommendation to patients was associated with personal NS use (OR = 3·38, P < 0·001), considering pharmacists as a source of information on DS (OR = 2·29, P = 0·01) and discussing DS with patients (OR = 3·82, P = 0·01). Having personally used HS (OR = 12·23, P < 0·001) and having discussed DS with patients (OR = 8·51, P = 0·01) increased the likelihood of recommending HS.

CONCLUSIONS

A proper DS education, the elaboration of national scientific guidelines and the implementation of concise laws regarding the regulations of DS would play a crucial role in supporting dietitians' practices and improving the quality of patient care with respect to DS.

Exploration of Predictive Modeling of Defense Health Agency & Department of Veterans Affairs Beneficiaries Dietary Supplements Use

PURPOSE

The purpose of this study was to predict dietary supplements (DS) use among Defense Health Agency (DHA) and Veterans Affairs (VA) beneficiaries who were scheduled for surgical procedures.

DESIGN

This was a predictive descriptive multicenter study with a convenience sample of 2,623 adult subjects. After institutional review board exemption, data collection occurred preoperatively via electronic survey. Participation was voluntary and data unidentifiable.

METHODS

Data were collected in preoperative anesthesia clinics during preanesthetic evaluations, or in surgery holding areas immediately prior to surgery, using a validated data collection tool. The total convenience sample size was 2,623 subjects from 6 medical centers. Data were voluntarily, anonymously, and verbally obtained from subjects using electronic survey methodology. Collected data included: gender, age, rank, beneficiary status, race, body mass index, tobacco use, marital status, and knowledge of DS side effects and drug interactions. For predictive modeling of DS use, multiple logistic regression was performed for binary outcomes via SPSS.

FINDINGS

For binary logistic regression the predictors were significant for the following outcomes: taking DS (education, sex, age, and race; P < .05), knowledge of side effects (age, race, and rank; P < .05), and believe they are having side effects (age; P < .05).

CONCLUSIONS

Understanding DS use is central to predict and anticipate potential negative sequelae in patient outcomes in anesthesia. College education, females, Caucasians, and increasing age are indicators for greater DS use. These results provide opportunities for perianesthesia nurses to improve preoperative assessments, design patient specific perianesthesia care, and enhance patient education. Further research is recommended.

Evaluation of dietary supplement, functional food and herbal medicine use by dietitians during the COVID-19 pandemic

OBJECTIVE

The current study was conducted to evaluate the dietary habits of the dietitians who had a leading role in this regard during the pandemic and their use of dietary supplements, functional food and herbal medicines.

DESIGN

A cross-sectional study. An online questionnaire was used as a data collection tool to identify the participants’ socio-demographic characteristics, health statuses and dietary habits and their use of dietary supplements, functional foods and herbal medicines.

SETTING

Turkey.

PARTICIPANTS

The study population was 550 dietitians.

RESULTS

In the current study, the participants’ average age was 30·6 ± 9·1 years, and most of them (88·2 %) were women. More than half of the participants (88·9 %) thought that adequate and balanced nutrition would positively affect the course of COVID-19. To avoid COVID-19, 94·5 % of the dietitians used dietary supplements, 46·1 % herbal medicines and 34·9 % functional foods during the pandemic. The most commonly used dietary supplement was fish oil (81·9 %), functional food was vegetables and fruits (80·5 %) and the herbal medicine was cinnamon (63·5 %). Women’s consumption of functional foods was approximately twice higher compared with men (95 % Cl: 1·048, 4·165; P < 0·05). The findings showed that the longer the dietitians were in their careers, the more functional foods and herbal medicines they used.

CONCLUSION

During the pandemic, dietitians’ use of foods with protective effects against diseases increased depending on their academic knowledge and experience in nutrition. The findings obtained in the current study suggest that an expert’s opinion should be obtained before using dietary supplements and herbal medicines.

ASSOCIATION BETWEEN ORAL IRON SUPPLEMENTATION AND RETINAL OR SUBRETINAL HEMORRHAGE IN THE COMPARISON OF AGE-RELATED MACULAR DEGENERATION TREATMENT TRIALS

PURPOSE

Because patients often take iron supplements without medical indication, and iron can accumulate in vascular endothelial cells, the authors evaluated the association of oral iron supplementation with retinal/subretinal hemorrhage in patients with neovascular age-related macular degeneration.

METHODS

A post hoc secondary data analysis of comparison of age-related macular degeneration treatments trials was performed. Participants were interviewed for use of oral iron supplements. Trained readers evaluated retinal/subretinal hemorrhage in baseline fundus photographs. Adjusted odds ratios from multivariate logistic regression models assessed the association between iron use and baseline hemorrhage adjusted by age, sex, smoking, hypertension, anemia, and use of antiplatelet/anticoagulant drugs.

RESULTS

Among 1,165 participants, baseline retinal/subretinal hemorrhage was present in the study eye in 71% of 181 iron users and in 61% of 984 participants without iron use (adjusted odds ratio = 1.47, P = 0.04), and the association was dose dependent (adjusted linear trend P = 0.048). Iron use was associated with hemorrhage in participants with hypertension (adjusted odds ratio = 1.87, P = 0.006) but not without hypertension. The association of iron use with hemorrhage remained significant among hypertensive participants without anemia (adjusted odds ratio = 1.85, P = 0.02).

CONCLUSION

Among participants of comparison of age-related macular degeneration treatments trials, the use of oral iron supplements was associated with retinal/subretinal hemorrhage in a dose-response manner. Unindicated iron supplementation may be detrimental in patients with wet age-related macular degeneration.

Dietetics Program Directors in the United States Support Teaching Vegetarian and Vegan Nutrition and Half Connect Vegetarian and Vegan Diets to Environmental Impact

Registered Dietitian Nutritionists (RDNs) are clinicians trained in the application of food, nutrition, and dietetics. Vegetarians and vegans have a lower risk of many nutrition-related chronic diseases that are epidemic while vegetarian and vegan diets are associated with reduced environmental impact. Despite this strong diet-disease and diet-environment connection, it is not known if dietetics students are taught the principles of vegetarian and vegan nutrition. The overarching goal of our study was to investigate curricular practices in accredited dietetics training programs in the United States (U.S.) including (1) the prevalence and perceived importance of vegetarian and vegan nutrition instruction and (2) if program directors connect vegetarian and vegan diets to climate change mitigation and resource conservation. Primary data were collected by way of a cross-sectional, Internet-based survey. All Accreditation Council for Education in Nutrition and Dietetics (ACEND) program directors in the U.S. (N = 574) were sent a 37-question survey and invited to participate in the study. Outcome measures included the prevalence of vegetarian and vegan nutrition instruction, quantifying if relationships exist among variables, and the frequency of connecting vegetarian and vegan diets to environmental impact. Descriptive and inferential statistics were utilized. Respondents (n = 205) indicated that over 51% of programs teach vegetarian nutrition while 49% teach vegan nutrition. There were significant differences between program type and the prevalence of vegetarian (p = 0.00005) and vegan (p = 0.00005) nutrition instruction. Over 90% of program directors believe that vegetarian and vegan nutrition should be taught. Over 50% of programs identify the connection between vegetarian and vegan diets in climate change mitigation and resource conservation. Most ACEND program directors believe vegetarian and vegan nutrition should be taught and half connect diet to environmental concern. Nevertheless, there is a discrepancy between beliefs and practice behaviors. These results suggest the need for increased collaboration and the use of novel techniques that better incorporate vegan and vegetarian nutrition throughout dietetics education.

Starch quality traits of improved provitamin A cassava (Manihot esculenta Crantz)

Provitamin A cassava clones were analysed for starch yield and critical starch quality attributes, to understand possible applications in the food industry. Total carotenoids content in the test clones ranged from 0.03-11.94 μg g^-1 of fresh root. Starch yield ranged from 8.4-33.2 % and correlated negatively (r = -0.588, P < 0.001) with carotenoids content. Amylose content (16.4–22.1%) didn't differ significantly (P ≤ 0.05) among the cassava clones. Meanwhile, total carotenoid content had significant negative correlations (P ≤ 0.05) with starch pasting temperature, peak time, setback viscosities and peak area. The reduced peak time and pasting temperatures in high-carotenoid cassava signifies reduction in energy requirements in yellow-fleshed roots when compared to white-fleshed cassava. This attribute is desirable for the food industry as it would reduce the overall cost of processing the cassava. Furthermore, final viscosities of starch from carotenoid-rich cassava were lower than those of white-fleshed roots, making provitamin A cassava suitable for soft food processing.

Protein Supplement Usage Among Male University Students: Comparisons Between Current and Previous Users

OBJECTIVE

Interest in specialized dietary supplements is leading market growth, and protein supplements are popular for increasing muscle mass among young males. Therefore, this study investigated the attitudes toward and satisfaction with protein supplements to identify detailed consumer behaviors related to the consumption of protein supplements.

METHOD

The study sample includes male university students in their 20s in South Korea. In total, 223 responses were entered for analysis. Questions related to attitudes, satisfaction, and future behavioral intentions were asked using 5-point Likert scales. The responses were divided into two groups, current and previous users, to identify significant differences in terms of attitudes, satisfaction, and future behavioral intentions. A descriptive analysis, analysis of variance (ANOVA), and multiple regression were run.

RESULTS

The majority of respondents prefer the powdered form of supplements in bulk with a price range between 30,000 won and 60,000 won. Online shopping was preferred, while word of mouth and friends/family were considered credible information sources. The most common side effects experienced were problems with digestion and hives, although more than 78% did not experience side effects. In comparison between current and previous users in terms of attitudes and satisfaction, the following areas showed significances. Regarding attitudes, the importance of brand, preference for products from overseas, the search for nutritional facts, and reading carefully all product information were significant, while regarding satisfaction, price, effectiveness, and ease of consumption were significant. All significances showed that current users had more positive attitudes and greater satisfaction. Overall, consumers' satisfaction regarding ease of consumption influenced future behavioral intentions.

CONCLUSIONS

The market for protein supplements has been growing, so measuring consumers' attitudes and satisfaction would help attract potential consumers. In addition, analyzing previous users' opinions on products could guide product development and encourage customers to return for repurchase.

A Low Dose Caffeine and Carbohydrate Supplement does not Improve Athletic Performance during Volleyball Competition

Dietary supplements are widely used to enhance sport performance and the combination of carbohydrate and caffeine (CHO+CAF) has yielded particularly high performance gains. Though the effects of a CHO+CAF supplement have been studied in a laboratory environment, little research exists on the effects of supplementation during competition. Therefore, the purpose of this study was to determine the effects of a CHO+CAF supplement on athletic performance in competition. Eight female collegiate volleyball players completed three testing sessions under three different conditions separated by approximately one week each: CHO+CAF supplement, placebo (PBO), and control (CTL) using a randomized, cross-over design. Blood glucose (BG) was assessed prior to supplementation and immediately after set three. The supplement and PBO were administered prior to play and between sets two and three. Following three sets of play, three performance tests were completed: vertical jump (VJ), agility (AGL), and repeated 30-m sprint ability (RSA). While CHO+CAF supplementation significantly increased BG, the performance tests were not different (p>.05) among the testing conditions. These findings suggest that the amount of the supplement used in this study is not beneficial to VJ, AGL, and RSA in female volleyball players. As these performance tests were largely anaerobic and non-glycolytic in nature, the ergogenicity of the supplement may have been underutilized. Additionally, coaches and athletes should not only be aware of what ingredients are in the supplements they choose, but the amount of those ingredients as they may modify the efficacy of the supplement to impact performance.

Demographic factors associated with dietary supplement prescriptions filled by United States Military Service Members 2005-2013

BACKGROUND

Dietary supplements (DSs) can be purchased over-the-counter but may also be prescribed by medical personnel for specific therapeutic reasons. Few studies have examined this latter source of DSs despite the fact that 79% of physicians and 82% of nurses have recommended DSs to their patients. This investigation examined demographic factors associated with temporal trends in oral DS prescriptions filled by all United States (US) service members (SMs) from 2005 to 2013 (n = 1,427,080 ± 22,139, mean ± standard deviation per year).

METHODS

The Food and Drug Administration National Drug Code database and the formularies of the US Defense Health Agency's Pharmacoeconomic Center were queried to identify DSs available to SMs. The number of these DS prescriptions filled by all SMs from 2005 through 2013 was then obtained from the US Department of Defense Pharmacy Data Transaction System. Data were grouped by American Hospital Formulary System (AHFS) pharmacologic-therapeutic classifications and examined over time. Denominators (number of SMs each year) were obtained from the Defense Health Agency.

RESULTS

Major findings included 1) generally greater prevalence of prescriptions filled by women and older SMs for most AHFS categories; 2) a temporal decline in total prescriptions filled by Marine Corps personnel accounted for by a decline in the prevalence of zinc preparations filled by younger male Marines; 3) a temporal decline in the prevalence of iron preparations filled by women; 4) a temporal increase in the prevalence of prescriptions for replacement preparations filled by women accounted for largely by more prescriptions for calcium compounds; and 5) a temporal decline in the prevalence of prescriptions filled for cathartics/laxatives in older SMs accounted for largely by a decline in prescriptions for sodium/potassium compounds.

CONCLUSIONS

These temporal trends may be associated with the greater health care utilization of women and older SMs as well as the perceptions of prescribers and/or patients on appropriate roles of these substances in medicine and public health.

Temporal trends in dietary supplement prescriptions of United States military service members suggest a decrease in pyridoxine and increase in vitamin D supplements from 2005 to 2013

Dietary supplements (DSs) can be obtained over-the-counter but can also be prescribed by health-care providers for therapeutic reasons. Few studies have documented this later source despite the fact that 79% of physicians and 82% of nurses have recommended DSs to patients. This investigation assessed prevalence and temporal trends in oral DS prescriptions filled by all United States service members (SMs) from 2005 to 2013 (n = 1 427 080 ± 22 139, mean ± standard deviation (SD)/y). We hypothesize that there would be temporal variations in specific types of DSs. Data obtained from Department of Defense Pharmacy Data Transaction System were grouped by American Hospital Formulary System pharmacologic-therapeutic classifications and prevalence examined over time. About 11% of SMs filled one or more DS prescriptions of 235 180 ± 4926 (mean ± SD) prescriptions/y over the 9-year period. Curve-fitting techniques indicated significant linear declines over time for multivitamins (P = .004), iron preparations (P < .001), antacids (P < .001), and vitamin B and B complex vitamins (P < .001). There were significant quadratic trends indicating a rise in early years followed by a leveling off in later years for replacement preparations (P < .001) and vitamin C (P < .001). There were significant quadratic trends (P < .001) for vitamin E indicating a decline in early years and leveling off in later years, and vitamin D indicating little change in early years followed by a large rise subsequently (P < .001). This study identified temporal trends in specific DS categories that may be associated with changing perceptions of prescribers and/or patients of the appropriate roles of DSs in medicine and public health.

Prevalence of Dietary Supplement Use by Athletes: Systematic Review and Meta-Analysis

BACKGROUND

Dietary supplements (DSs) are commercially available products consumed as an addition to the usual diet and are frequently ingested by athletes.

OBJECTIVE

Our objective was to examine the prevalence of DS use by athletes.

DATA SOURCES

PubMed, Ovid MEDLINE, OVID Healthstar, and Cumulative Index to Nursing and Allied Health were searched for original research articles published up to August 2014. Search terms included specific sports, specific DSs, and other terms.

STUDY SELECTION

Studies were selected if they were written in English, involved athletes, and provided a quantitative assessment of the proportion of athletes using specific DSs. Percent of athletes using specific DSs.

SYNTHESIS OF DATA

Methodological quality of studies was assessed by three reviewers using an 8-point scale that included evaluations for sampling methods, sampling frame, sample size, measurement tools, bias, response rate, statistical presentation, and description of the participant sample. Where there were at least two investigations, meta-analysis was performed to obtain summary (pooled) prevalence estimates (SPEs) on (1) DS use prevalence by sport and sex, (2) DS use prevalence by elite versus non-elite athletic status, and (3) specific DS prevalence for all athletic groups combined. Meta-analyses included evaluations of homogeneity and publication bias.

RESULTS

A total of 159 unique studies met the review criteria. Methodological quality was generally low with an average ± standard deviation of 43 ± 16% of available rating points. There was low homogeneity for SPEs when compiled by sport, athletic status, and/or specific DSs. Contributing to the lack of homogeneity were differences in studies' objectives and types of assessments used (e.g., dietary surveys, interviews, questionnaires). Despite these limitations, the data generally indicated that elite athletes used DSs much more than their non-elite counterparts. For most DSs, use prevalence was similar for men and women except that a larger proportion of women used iron while a larger proportion of men used vitamin E, protein, and creatine. No consistent change in use over time was observed because even the earliest investigations showed relatively high use prevalence.

CONCLUSION

It was difficult to generalize regarding DS use by athletes because of the lack of homogeneity among studies. Nonetheless, the data suggested that elite athletes used dietary supplements far more than their non-elite counterparts; use was similar for men and women with a few exceptions; use appeared to change little over time; and a larger proportion of athletes used DSs compared with the general US population. Improvements in study methodology should be considered in future studies especially (1) defining DSs for participants; (2) querying for very specific DSs; (3) using a variety of reporting timeframes (e.g., daily, 2-6 times/week, 1 time/week and <1 time/week); (4) reporting the sampling frame, number of individuals solicited, and number responding; (5) reporting characteristics of volunteers (and non-volunteers, if available); and (6) using similar methods on several occasions to examine possible temporal trends among athletes.

Consumer attitudes about the role of multivitamins and other dietary supplements: report of a survey

BACKGROUND

U.S. nutrition surveys find that intakes of many nutrients fall short of recommendations. The majority of U.S. adults use multivitamins and other dietary supplements as one means of improving nutrient intakes. Some policy makers and health professionals appear reluctant to recommend routine use of dietary supplements to fill nutrient gaps in the diet, in part because they are concerned that people will view the supplements as a substitute for dietary improvement and that the use of supplements may lead to overconsumption of micronutrients. Surveys find that in fact users of dietary supplements tend to have better diets and adopt other healthy habits, suggesting that the supplements are viewed as one aspect of an overall effort to improve wellness. Furthermore, evidence demonstrates that the incidence of excess micronutrient intake is low. We report the results of a survey probing consumer attitudes about the role of dietary supplements.

METHODS

The Council for Responsible Nutrition funded a survey to measure consumer attitudes about the role of multivitamins, calcium and/or vitamin D supplements, and other supplements in improving dietary intakes. The research was designed and analyzed by FoodMinds and was fielded using Toluna's On-line Omnibus. The weighted sample of 2159 respondents is representative of U.S. adults.

RESULTS

Nearly 90% of the survey respondents agreed that multivitamins and supplements of calcium and/or vitamin D can help meet nutrient needs when desirable intakes are not achieved through food alone. At the same time, 80% agreed that dietary supplements should not be used to replace healthy dietary or lifestyle habits, and 82% agreed that people considering taking a high dose, single nutrient supplement should talk with their physician.

CONCLUSIONS

These results provide additional support for the conclusion that the vast majority of consumers recognize that multivitamins and other supplements can help fill nutrient gaps but should not be viewed as replacements for a healthy diet. This suggests that policy makers and health professionals could feel comfortable recommending rational dietary supplementation as one means of improving nutrient intakes, without being unduly concerned that such a recommendation would lead consumers to discount the importance of good dietary habits.

Online Education Improves Canadian Dietitians' Attitudes and Knowledge Regarding Recommending and Ordering Multivitamin/Mineral Supplements

PURPOSE

To determine the attitudes and knowledge of Fraser Health registered dietitians (RDs) regarding recommending and ordering multivitamin/mineral supplements prior to and following an online education module.

METHODS

The educational intervention consisted of narrated slides with electronic resources. After undergoing external review for face and content validity, 6 attitude questions and a 15-item knowledge test were administered pre- and postintervention. The attitude questionnaire utilized a 5-point Likert scale and had a maximum summative score of 30 points. The knowledge test was worth a maximum of 15 points.

RESULTS

Of the eligible RDs (n = 123), 57 (46.3%) completed the study and 55 participants were included in the final analyses. Summative attitude scores were higher on the post-intervention questionnaire compared with the preintervention questionnaire (t = 92.5, P < 0.001). The proportion of correctly answered knowledge questions pre- (78.0% ± 10.0%) to postintervention (mean = 87.4% ± 6.0%) increased significantly (t = 7.16, P < 0.001).

CONCLUSIONS

Postintervention, RD attitudes and knowledge improved confirming that the education strategy was effective. Future work should focus on optimizing the module and knowledge questions.

Micronutrient supplement use and diet quality in university students

Many national and international public health organisations recommend achieving nutrient adequacy through consumption of a wide variety of nutritious foods. Despite this, dietary supplement sales continue to increase. Understanding the characteristics of micronutrient supplement users and the relationship with diet quality can help develop effective public health interventions to reduce unnecessary consumption of vitamin and mineral supplements. Participants (n = 1306) were a convenience sample of students studying first year food and nutrition. Data was collected via a Food and Diet Questionnaire (FDQ) and a Food Frequency Questionnaire (FFQ). Supplement users were defined as participants who indicated consuming any listed supplement as frequently as once a month or more. Diet quality was assessed using a Dietary Guideline Index (DGI) score. Prevalence of supplement use was high in this study population with 56% of participants reporting supplement use; the most popular supplements consumed were multivitamins (28%) and vitamin C (28%). A higher DGI score was significantly associated with an increased likelihood of supplement use (mean: 105 ± 18 vs. 109 ± 17, p = 0.001). Micronutrient supplement use was associated with a higher DGI score, suggesting that supplements are more likely to be used by those who are less likely to require them.

Consumer usage and reasons for using dietary supplements: report of a series of surveys

OBJECTIVE

Consumer usage of dietary supplements is prevalent in the United States, and total usage is higher than reported in recent National Health and Nutrition Examination Surveys (NHANES), because these surveys capture usage only in the 30 days prior to the respondent's interview and do not capture occasional and seasonal use throughout the year. We report data from a series of consumer surveys on the full extent of dietary supplement use, on the reasons for supplement use, and on the products most commonly taken, as well as other health habits of supplement users.

METHODS

The Council for Responsible Nutrition (CRN), a trade association of the dietary supplement industry, has contracted with Ipsos Public Affairs to conduct consumer surveys annually since 2000. The surveys have been administered online since 2007 to about 2000 subjects each year. We report 5 years of data (2007 to 2011) on the prevalence of dietary supplement use, as well as more detailed data from the 2011 survey on the products used, the reasons for using supplements, and other health habits of supplement users.

RESULTS

The prevalence of supplement use fluctuated within the range of 64% to 69% from 2007 to 2011, and the prevalence of regular supplement use ranged from 48% to 53%, with no statistically significant differences from year to year. Over the 5-year period, the percentage of respondents who said that they regularly used a variety of supplements increased from 28% to 36%, and the increase from 2010 to 2011 was statistically significant. The percentage of respondents who said that they regularly used only a multivitamin, as opposed to a variety of supplements, declined from 24% to 17%, and the decrease from 2007 to 2008 was statistically significant. Detailed results from the 2011 survey confirm that supplement use increases with age and is higher in women than in men. Vitamin or mineral supplements were used by 67% of all respondents in 2011, specialty supplements by 35%, botanicals by 23%, and sports supplements by 17%. Among supplement users, multivitamins were the most commonly used supplement (71%), followed by omega-3 or fish oil (33%), calcium (32%), vitamin D (32%), and vitamin C (32%). The reasons most often cited for supplement use were for overall health and wellness (58%) and to fill nutrient gaps in the diet (42%). Supplement users were significantly more likely than nonusers to say that they try to eat a balanced diet, visit their doctor regularly, get a good night's sleep, exercise regularly, and maintain a healthy weight.

CONCLUSIONS

Annual consumer surveys over a period of 5 years show that dietary supplement use is somewhat more prevalent in the United States than has been reported in the NHANES surveys, when occasional and seasonal use are taken into account, in addition to regular use. Most dietary supplement users take a multivitamin, and many take a variety of products. The primary reasons given for supplement use are for overall health and wellness or to fill nutrient gaps. Users of dietary supplements are more likely than nonusers to adopt a variety of healthy habits, indicating that supplement use is part of an overall approach to living healthy.

A systematic review of multivitamin-multimineral use and cardiovascular disease and cancer incidence and total mortality

Multivitamin-multimineral (MVM) supplements are the most frequently used dietary supplements in the United States, with one third or more of the population using at least one daily. However, the health-related implications of MVM use are unclear. Thus, we systematically reviewed and summarized the prospective studies of MVM supplementation and all-cause and cause-specific mortality, as well as cardiovascular disease (CVD) and cancer incidence, to critically evaluate the current evidence on this topic. We included studies of generally healthy adult populations that evaluated multivitamin (the most commonly used dietary supplement) and/or multimineral supplement use or simultaneous use of 3 or more vitamins and minerals. We did not evaluate individual supplements. A total of 12 cohort studies and 3 primary prevention randomized controlled trials met our inclusion criteria. The majority of the studies were conducted in the United States (n = 11), and the remaining were conducted in European countries (n = 3) and Japan (n = 1). Although between-study methodological variation was present, most relative risks hovered closely around or slightly below the null value. No clear patterns of associations by study country, gender, smoking status, or frequency of use were observed. Based upon the available scientific evidence to date, supplementation with MVMs does not appear to increase all-cause mortality, cancer incidence or mortality, or CVD incidence or mortality and may provide a modest protective benefit.

A systematic review and meta-analysis on the prevalence of dietary supplement use by military personnel

Background

Although a number of studies have been conducted on the prevalence of dietary supplement (DS) use in military personnel, these investigations have not been previously summarized. This article provides a systematic literature review of this topic.

Methods

Literature databases, reference lists, and other sources were searched to find studies that quantitatively examined the prevalence of DS use in uniformed military groups. Prevalence data were summarized by gender and military service. Where there were at least two investigations, meta-analysis was performed using a random model and homogeneity of the prevalence values was assessed.

Results

The prevalence of any DS use for Army, Navy, Air Force, and Marine Corps men was 55%, 60%, 60%, and 61%, respectively; for women corresponding values were 65%, 71%, 76%, and 71%, respectively. Prevalence of multivitamin and/or multimineral (MVM) use for Army, Navy, Air Force, and Marine Corps men was 32%, 46%, 47%, and 41%, respectively; for women corresponding values were 40%, 55%, 63%, and 53%, respectively. Use prevalence of any individual vitamin or mineral supplement for Army, Navy, Air Force, and Marine Corps men was 18%, 27%, 25%, and 24%, respectively; for women corresponding values were 29%, 36%, 40%, and 33%, respectively. Men in elite military groups (Navy Special Operations, Army Rangers, and Army Special Forces) had a use prevalence of 76% for any DS and 37% for MVM, although individual studies were not homogenous. Among Army men, Army women, and elite military men, use prevalence of Vitamin C was 15% for all three groups; for Vitamin E, use prevalence was 8%, 7%, and 9%, respectively; for sport drinks, use prevalence was 22%, 25% and 39%, respectively. Use prevalence of herbal supplements was generally low compared to vitamins, minerals, and sport drinks, ≤5% in most investigations.

Conclusions

Compared to men, military women had a higher use prevalence of any DS and MVM. Army men and women tended to use DSs and MVM less than other service members. Elite military men appeared to use DSs and sport drinks more than other service members.

Health habits and other characteristics of dietary supplement users: a review

Dietary supplements are used by half to two-thirds of American adults, and the evidence suggests that this usage is one component of a larger effort to develop a healthier lifestyle. Dietary supplement users tend on average to be better educated and to have somewhat higher incomes than nonusers, and these factors may contribute to their health-consciousness. Dietary supplement use also tends to be more prevalent among women than among men, and the prevalence of use increases with age in both men and women. Numerous surveys document that users of dietary supplements are significantly more likely than nonusers to have somewhat better dietary patterns, exercise regularly, maintain a healthy weight, and avoid tobacco products. While supplement users tend to have better diets than nonusers, the differences are relatively small, their diets have some substantial nutrient shortfalls, and their supplement use has been shown to improve the adequacy of nutrient intakes. Overall, the evidence suggests that users of dietary supplements are seeking wellness and are consciously adopting a variety of lifestyle habits that they consider to contribute to healthy living.

Dietary supplement recommendations by Saskatchewan chiropractors: results of an online survey

Background

Chiropractors receive training in nutrition during their education, previous surveys have found that chiropractors frequently provide recommendations to patients relating to nutrition and dietary supplement intake. However, it has not been ascertained which specific supplements chiropractors recommend or the types of health conditions for which supplement recommendations are made.

Objective

The purpose of this study was to determine which dietary supplements are most commonly recommended by chiropractors in the province of Saskatchewan,Canada and the health conditions for which supplement recommendations are made.

Design

An online survey of licensed chiropractors practicing in the province of Saskatchewan, Canada was distributed three times following online and in-person notifications of the survey.

Statistical analyses performed

Descriptive statistics were reported, predominantly in the form of means and proportions.

Results

A response rate of 45% was obtained. All of the respondents (100%) indicated providing nutritional advice or counselling to patients, while nearly all (99%) indicated providing dietary supplement recommendations to patients. Respondents estimated that they provide nutritional advice or counselling to 31% of their patients on average, and recommend dietary supplements to an average of 25% of their patients. The most commonly recommended supplements were glucosamine sulfate, multivitamins, vitamin C, vitamin D, calcium, omega-3 fatty acids, and probiotics. The most common reasons to recommend dietary supplements were for “general health and wellness” (82% of respondents), “bone health” (74%), “rheumatologic, arthritic, degenerative, or inflammatory conditions’ (72%), and “acute and/or chronic musculoskeletal conditions” (65%).

Conclusion

The majority of respondents indicated providing nutritional counselling and recommendations for dietary supplements to their patients. Respondents generally recommend a small number of dietary supplements and provide these recommendations and counselling to fewer than half of their patients on average, while tending to focus on conditions most closely related to the scope of practice of chiropractors. The findings of this study may have been limited by selection bias owing to the low response rate and as those who respond to surveys are often more likely to respond positively.