Analytical ingredient content and variability of adult multivitamin/mineral products: national estimates for the Dietary Supplement Ingredient Database

Analysis of US Marketed Artemisinin Supplements for Use in Dogs

Oral artemisinin has antiparasitic activity and may help improve treatment success rates in dogs infected with Babesia gibsoni. However, these artemisinin products are unapproved and unregulated botanical supplements. They have not been evaluated for safety and efficacy or for strength, purity, or quality compared with a reference standard. Before considering these products for a clinical study, we evaluated the strength of four suppliers of artemisinin capsules using an high-performance liquid chromatography method validated in our laboratory. We found that the four artemisinin-labeled products that were tested had high within product and between product variability in capsule strength compared with the stated capsule strength on the product label. No products met the acceptance criteria of the United States Pharmacopeia and International Council for Harmonisation (ICH) as well as the criteria adapted by the authors. One product had no detectable artemisinin, and the other three products were much higher than the stated label strength. The results of this study reinforce the importance of testing unapproved and unregulated supplements before recommending a supplement for clinical use in dogs.

Content-Related Quality Control of Water- and Fat-Soluble Vitamins in Fortified Non-Alcoholic Beverages

BACKGROUND/OBJECTIVES

Vitamin-fortified non-alcoholic beverages (VFNABs) are rising in popularity and availability. However, owing to their regulation as foods, there are also growing quality and safety concerns. Therefore, we aimed to provide an overview of the content-related quality of VFNABs on the Slovenian market.

METHODS

Vitamin contents in 50 VFNABs (29 waters, 5 juices, 12 energy drinks, and 4 instant drinks) were determined using validated methods based on liquid chromatography.

RESULTS

The results revealed several quality issues, which were determined in all four VFNAB types. These included an indication of at least one vitamin, present in a lower-than-significant amount, on the nutrition declaration in 64% of the tested VFNABs and vitamin contents outside the tolerance interval (65-150% of the label claim) in almost half of the cases (48.4%, n = 244). Since the disclosed quality issues are not only a reason for the misleading of consumers but may also pose safety risks for both individuals and public health, we further performed an overall assessment of the VFNABs as vitamin sources. The results revealed that the tested VFNABs not only fully cover but in several cases considerably exceed daily vitamin needs (up to 616% of the reference values), an effect which is further accentuated in children.

CONCLUSIONS

The performed content-related quality control study undoubtedly highlight the need for stricter quality control and regulation and can be utilized as a foundation and recommendation for the manufacturers in terms of committing to and pursuing the production of VFNABs.

The Evolution of Science and Regulation of Dietary Supplements: Past, Present, and Future

Dietary supplement use in the United States is widespread and increasing, especially among certain population groups, such as older Americans. The science surrounding dietary supplements has evolved substantially over the last few decades since their formal regulation in 1994. Much has been learned about the mechanisms of action of many dietary supplement ingredients, but the evidence on their health effects is still building. As is true of much nutrition research, there are many studies that point to health effects, but not all are at the level of scientific evidence (e.g., randomized controlled interventions), rigor, or quality needed for definitive statements of efficacy regarding clinical end points. New technologies and approaches are being applied to the science of dietary supplements, including nutrigenomics and microbiome analysis, data science, artificial intelligence (AI), and machine learning-all of which can elevate the science behind dietary supplements. Products can contain an array of bioactive compounds derived from foods as well as from medicinal plants, which creates enormous challenges in data collection and management. Clinical applications, particularly those aimed at providing personalized nutrition options for patients, have become more sophisticated as dietary supplements are incorporated increasingly into clinical practice and self-care. The goals of this article are to provide historical context for the regulation and science of dietary supplements, identify research resources, and suggest some future directions for science in this field.

Active Molecular Network Discovery Links Lifestyle Variables to Breast Cancer in the Long Island Breast Cancer Study Project

A healthy lifestyle has been associated with decreased risk of developing breast cancer. Using untargeted metabolomics profiling, which provides unbiased information regarding lifestyle choices such as diet and exercise, we aim to identify the molecular mechanisms connecting lifestyle and breast cancer through network analysis. A total of 100 postmenopausal women, 50 with breast cancer and 50 cancer-free controls, were selected from the Long Island Breast Cancer Study Project (LIBCSP). We measured untargeted plasma metabolomics using liquid chromatography-high-resolution mass spectrometry (LC-HRMS). Using the "enet" package, we retained highly correlated metabolites representing active molecular network (AMN) clusters for analysis. LASSO was used to examine associations between cancer status and AMN metabolites and covariates such as BMI, age, and reproductive factors. LASSO was then repeated to examine associations between AMN metabolites and 10 lifestyle-related variables including smoking, physical activity, alcohol consumption, meat consumption, fruit and vegetable consumption, and supplemental vitamin use. Results were displayed as a network to uncover biological pathways linking lifestyle factors to breast cancer status. After filtering, 851 "active" metabolites out of 1797 metabolomics were retained in 197 correlation AMN clusters. Using LASSO, breast cancer status was associated with 71 "active" metabolites. Several of these metabolites were associated with lifestyle variables including meat consumption, alcohol consumption, and supplemental β-carotene, B12, and folate use. Those metabolites could potentially serve as molecular-level biological intermediaries connecting healthy lifestyle factors to breast cancer, even though direct associations between breast cancer and the investigated lifestyles at the phenotype level are not evident. In particular, DiHODE, a metabolite linked with inflammation, was associated with breast cancer status and connected to β-carotene supplement usage through an AMN. We found several plasma metabolites associated with lifestyle factors and breast cancer status. Future studies investigating the mechanistic role of inflammation in linking supplement usage to breast cancer status are warranted.

Commercially Available Prenatal Vitamins Do Not Meet American College of Obstetricians and Gynecologists Nutritional Guidelines

OBJECTIVE

This study aimed to evaluate the reported amount of the American College of Obstetricians and Gynecologists (ACOG) recommended nutrients in commercially available, over-the-counter prenatal vitamins (PNVs) in the United States, to assess their adequacy compared with the ACOG guidelines, and to compare these supplements by cost.

STUDY DESIGN

The top 30 online Amazon and Google shopping items found using "prenatal vitamins" in September 2022 were included for analysis if they included the words "prenatal" and "vitamin" in the label and contained multiple nutrients. Duplicates between Amazon and Google were excluded as well as vitamins that did not list all ingredients. The reported amounts of 11 key nutrients, as recommended by the ACOG, for each product were recorded, as well as supplemental form and cost per 30-day supply. A cost analysis was done of PNVs that met the ACOG recommendations for the highlighted nutrients compared with those that did not. Five out of the 11 key nutrients (folic acid, iron, docosahexaenoic acid, vitamin D, and calcium) were specifically highlighted, as deficiencies in these nutrients are known to correlate with significant clinical outcomes in pregnancy.

RESULTS

A total of 48 unique PNVs were included for final analysis. Of these PNVs, none were compliant with suggested amounts of all five key vitamins and nutrients. No products met daily recommendations for calcium. Only five PNVs were compliant with recommendations with 4/5 key nutrients. Of note, 27% of PNVs did not have the recommended amount of folic acid (13/48). The median cost of PNVs that were not compliant with the four nutrients mentioned above was $18.99 (interquartile range [IQR]: $10.00-30.29), which was not statistically different from the median cost of the PNVs that did meet compliance with the four nutrients, which was $18.16 (IQR: $9.13-26.99), p = 0.55.

CONCLUSION

There were significant variations in the level of nutrients and cost of commercially available, over-the-counter PNVs in the United States. This raises concern that there should be more regulation of PNVs.

KEY POINTS

· Commercially available over the counter PNVs vary in their content of the ACOG recommended nutrients and vitamins for pregnancy.. · None of these studied PNVs contain adequate amounts of all five key nutrients.. · Cost is not correlated with more compliance with the ACOG recommendations..

Assessment of calcium intake and recognition of calcium-rich food sources among the Saudi population

Calcium is an essential skeletal mineral, and calcium deficiency has a negative impact on bone health. We conducted an online questionnaire to assess the intake and knowledge among the Saudi population. The survey included 950 participants, with 51.1% demonstrating poor knowledge of calcium sources and a mean intake lower than the recommended level.

INTRODUCTION

Calcium is an essential mineral and one of the most prevalent in the body. Chronic insufficient calcium intake increases the risk of osteopenia, osteoporosis, and bone fracture.

PURPOSE

This study aimed to assess the Saudi population's calcium intake and knowledge of calcium sources as well as to identify factors associated with inadequate calcium intake.

METHODS

This cross-sectional study was conducted across Saudi Arabia using an online questionnaire distributed randomly through social media channels. The questionnaire was a validated tool that was previously developed and used by the original author to assess knowledge of calcium food sources and estimate calcium intake in the Saudi population. If an individual answered more than 11 questions correctly, calcium knowledge was considered adequate. Calcium intake was considered sufficient or insufficient based on the recommended dietary allowance (RDA) of 1000 mg/day.

RESULTS

The survey included male and female Saudi citizens and residents aged 14 years or older. A total of 950 respondents aged 9-70 completed the questionnaire. A total of 62.9% of the respondents were 26-50 years old. Of the participants, 64.2% were female, 71.7% were married, and 61.9% had a diploma or a bachelor's degree. Of these, 63.8% were from the central region, and 97.6% were from Saudi Arabia. For those aged 9-18, the average calcium consumption was 577 mg/day, whereas it was 479 mg/day for those aged 19-50. The average intake was 479 mg/day for males aged 51-70 (EAR = 1000 mg/day) and 438 mg/day for females (EAR = 1200 mg/day). These calcium consumption values were significantly lower than the estimated average requirement (EAR) and RDA (p < 0.01). Correct response rates for the 19 calcium intake knowledge items ranged from 23.4 to 94.7%. Among the participants, 48.9% had significant calcium intake knowledge, as indicated by a score of > 11 out of 19 correct responses. Age, sex, marital status, educational attainment, and residence were significantly correlated with adequate knowledge of calcium. Demographic characteristics such as age, marital status, and residence were associated with sufficient calcium intake in the study.

CONCLUSION

The study findings revealed that a significant proportion (51.1%) of participants demonstrated inadequate knowledge regarding calcium food sources. Additionally, the mean calcium intake was found to be lower than the RDA of 1300 mg/day for males and females 14-18 years old and 1000 mg/day for males and females 19-50 years old and males 51-70 years old; however, the RDA for females 51-70 years old is 1200 mg/day, suggesting an urgent need for interventions aimed at enhancing both calcium knowledge and intake.

Evaluating the Compliance, Efficacy, and Cost of Formulated Vitamins Versus Separate Supplements in Post-bariatric Surgery Patients

OBJECTIVE

Micronutrient deficiencies are common complications after bariatric surgery as alterations to the gastrointestinal tract change absorption. Patients are recommended to take supplements including multivitamins, B complex, calcium, vitamin D, and iron after bariatric surgery, and can take these as specifically formulated vitamins for post-bariatric patients or separate vitamin supplements. We investigated the compliance, efficacy, and cost of specifically formulated vitamins for post-bariatric patients in comparison to separate vitamin supplements.

METHODS

We surveyed 126 post-bariatric adult patients between February 1, 2022, and August 31, 2022, who had undergone bariatric surgery between 2014 and 2021 to assess the type of supplements taken, compliance, and cost. Demographics, type of bariatric surgery, and serum micronutrient levels were evaluated for all patients.

RESULTS

There were 51 patients taking formulated vitamins and 75 patients taking separate vitamins. The formulated vitamin group demonstrated greater adherence to optimal vitamin dosage (formulated vitamin group, 76.5% vs. separate supplement group, 30.7%; p < 0.001) and higher compliance (formulated vitamin group, 90.2% vs. separate supplement group, 66.7%; p = 0.002). The costs associated with both groups were comparable. No significant difference was observed in the incidence of micronutrient deficiency between the groups.

CONCLUSIONS

Our study shows that formulated vitamins do not offer significant difference in micronutrient levels or cost compared to separate standard vitamin supplements. However, formulated bariatric vitamins have improved compliance compared to separate vitamin supplements.

Iodine deficiency and real-life supplementation ineffectiveness in Polish pregnant women and its impact on thyroid metabolism

Introduction

Iodine is a pivotal component of thyroid hormones, and its deficiency leads to negative pregnancy outcomes. Therefore, during gestation, additional iodine supplementation is recommended.

Objectives

By evaluating a group of women from western Poland, the study updated on iodine status during pregnancy and the effectiveness of iodine supplementation in relation to the maternal and neonatal thyroid function.

Patients and methods

A total of 91 women were recruited before the delivery between 2019 and 2021. During the medical interview, the patients declared their dietary supplements intake. Thyroid parameters (TSH, ft3, ft4, a-TPO, a-Tg, and TRAb) were measured in the serum of mothers and in the cord blood of newborns after birth. Urinary iodine concentration (UIC) and urine/creatinine (UIC/crea) ratio were assessed in single urine samples using a validated high-performance liquid chromatography with ultraviolet detection (HPLC-UV). Neonatal TSH screening from dried blood spot was analyzed.

Results

Pregnant women showed a median (interquartile range) UIC of 106 (69-156) µg/liter and UIC/crea ratio of 104 (62-221) µg/g, whereas approximately 20% had UIC/crea below 50 µg/g, indicating iodine deficiency. The iodine supplementation ratio was 68%. No significant differences in UIC, UIC/crea and thyroid parameters were found between iodine supplemented and non-supplemented groups; however, the highest ioduria was detected when iodine was supplemented in addition to levothyroxine in comparison with both substances administered separately. Patients with UIC/crea within 150-249 µg/g demonstrated the lowest TSH and a-TPO levels. Screening TSH was above 5 mIU/liter in 6% of children.

Conclusions

Despite the national salt iodization and the recommendation to supplement iodine during gestation, the status of the abovementioned microelement and real-life intake revealed the ineffectiveness of the current iodine-deficiency prophylaxis model in pregnancy.

Simultaneous analysis of water-soluble and fat-soluble vitamins through RP-HPLC/DAD in food supplements and brewer's yeast

The current study is focused on investigation and quantitation of seven commercially available on the Bulgarian market food supplements, containing multivitamin mixtures of water-soluble and fat-soluble vitamins. In addition, a second fermentation brewer's yeast is also analyzed. The analytical procedures are performed on a RP-HPLC/DAD using Purospher STAR C18 (Merck Millipore, Germany) 5 μm, 25 × 0.46 cm column, conditioned at 25 °C in a column oven. Dionex UltiMate 3000 high performance liquid chromatograph was carried out in diode array detector, set up at 270 nm for water-soluble vitamins, except for vitamin B₅, where 210 nm was applied as analytical wavelength. The fat-soluble vitamins were detected at 325 nm and 265 nm for vitamin A and vitamin E, respectively. Two general methods were developed where Method 1 was based on gradient elution and Method 2 was based on isocratic elution. Both methods identified stated by the manufacturer labeled amounts. The developed methods are applicable for routine analysis of vitamin contents both in multivitamin preparations and in brewer's yeast from secondary fermentation.

Vitamin B12 in Foods, Food Supplements, and Medicines-A Review of Its Role and Properties with a Focus on Its Stability

Vitamin B₁₂, also known as the anti-pernicious anemia factor, is an essential micronutrient totally dependent on dietary sources that is commonly integrated with food supplements. Four vitamin B₁₂ forms-cyanocobalamin, hydroxocobalamin, 5'-deoxyadenosylcobalamin, and methylcobalamin-are currently used for supplementation and, here, we provide an overview of their biochemical role, bioavailability, and efficacy in different dosage forms. Since the effective quantity of vitamin B₁₂ depends on the stability of the different forms, we further provide a review of their main reactivity and stability under exposure to various environmental factors (e.g., temperature, pH, light) and the presence of some typical interacting compounds (oxidants, reductants, and other water-soluble vitamins). Further, we explore how the manufacturing process and storage affect B₁₂ stability in foods, food supplements, and medicines and provide a summary of the data published to date on the content-related quality of vitamin B₁₂ products on the market. We also provide an overview of the approaches toward their stabilization, including minimization of the destabilizing factors, addition of proper stabilizers, or application of some (innovative) technological processes that could be implemented and contribute to the production of high-quality vitamin B₁₂ products.

Safety of selenium exposure and limitations of selenoprotein maximization: Molecular and epidemiologic perspectives

Recent evidence from laboratory and epidemiologic studies has shed a different light on selenium health effects and its recommended range of environmental exposure, compared with earlier research. Specifically, epidemiologic studies in Western populations have shown adverse effects of selenium exposure at low levels, sometimes below or slightly above selenium intakes needed to maximize selenoprotein expression and activity. In addition, three recent lines of evidence in molecular and biochemical studies suggest some potential drawbacks associated with selenoprotein maximization: 1) the possibility that selenoprotein upregulation is a compensatory response to oxidative challenge, induced by selenium itself or other oxidants; 2) the capacity of selenoproteins to trigger tumor growth in some circumstances; and 3) the deleterious metabolic effects of selenoproteins and particularly of selenoprotein P. The last observation provides a toxicological basis to explain why in humans selenium intake levels as low as 60 μg/day, still in the range of selenium exposure upregulating selenoprotein expression, might start to increase risk of type 2 diabetes. Overall, these new pieces of evidence from the literature call into question the purported benefit of selenoprotein maximization, and indicate the need to reassess selenium dietary reference values and upper intake level. This reassessment should clarify which range of selenoprotein upregulation follows restoration of adequate selenium availability and which range is driven by a compensatory response to selenium toxicity and oxidative stress.

Application of Liquid Chromatography Coupled to Mass Spectrometry in Quality Assessment of Dietary Supplements-A Case Study of Tryptophan Supplements: Release Assay, Targeted and Untargeted Studies

Dietary supplements are widely consumed in the EU and the USA. Based on their similarity to pharmaceuticals, consumers mistakenly believe that dietary supplements have also been approved for safety and efficacy. However, in the absence of mandatory testing, data on supplement quality is scarce. Thus, we applied liquid chromatography coupled with tandem mass spectrometry to analyse the quality of dietary supplements containing tryptophan (Trp). We examined 22 supplements in tablets or capsules, produced in the USA, Great Britain, Germany, France, Czech Republic, and Poland. Trp release, crucial for bioavailability and efficiency, was assessed. Additionally, we performed a qualitative analysis of the main ingredient and screened for contaminants. Among the contaminants, we detected Trp's metabolites, condensation products of Trp and carbonyl compounds, Trp degradation products, degradation products of kynurenine, and other contaminants such as glucosamine and melatonin. The main ingredient content was in the range of 55-100% in capsules and 69-87% in tablets. Surprisingly, almost no Trp release was noted from some supplements. Our study confirms the need to advance research on supplements. We believe that the high-quality analysis of supplements based on reliable analytical techniques will be an important contribution to the discussion on the regulatory framework of these products.

Analytical Challenges and Metrological Approaches to Ensuring Dietary Supplement Quality: International Perspectives

The increased utilization of metrology resources and expanded application of its' approaches in the development of internationally agreed upon measurements can lay the basis for regulatory harmonization, support reproducible research, and advance scientific understanding, especially of dietary supplements and herbal medicines. Yet, metrology is often underappreciated and underutilized in dealing with the many challenges presented by these chemically complex preparations. This article discusses the utility of applying rigorous analytical techniques and adopting metrological principles more widely in studying dietary supplement products and ingredients, particularly medicinal plants and other botanicals. An assessment of current and emerging dietary supplement characterization methods is provided, including targeted and non-targeted techniques, as well as data analysis and evaluation approaches, with a focus on chemometrics, toxicity, dosage form performance, and data management. Quality assessment, statistical methods, and optimized methods for data management are also discussed. Case studies provide examples of applying metrological principles in thorough analytical characterization of supplement composition to clarify their health effects. A new frontier for metrology in dietary supplement science is described, including opportunities to improve methods for analysis and data management, development of relevant standards and good practices, and communication of these developments to researchers and analysts, as well as to regulatory and policy decision makers in the public and private sectors. The promotion of closer interactions between analytical, clinical, and pharmaceutical scientists who are involved in research and product development with metrologists who develop standards and methodological guidelines is critical to advance research on dietary supplement characterization and health effects.

The Importance of Reference Materials and Method Validation for Advancing Research on the Health Effects of Dietary Supplements and Other Natural Products

Insufficient assessment of the identity and chemical composition of complex natural products, including botanicals, herbal remedies, and dietary supplements, hinders reproducible research and limits understanding mechanism(s) of action and health outcomes, which in turn impede improvements in clinical practice and advances in public health. This review describes available analytical resources and good methodological practices that support natural product characterization and strengthen the knowledge gained for designing and interpreting safety and efficacy investigations. The practice of validating analytical methods demonstrates that measurements of constituents of interest are reproducible and appropriate for the sample (e.g., plant material, phytochemical extract, and biological specimen). In particular, the utilization of matrix-based reference materials enables researchers to assess the accuracy, precision, and sensitivity of analytical measurements of natural product constituents, including dietary ingredients and their metabolites. Select case studies are presented where the careful application of these resources and practices has enhanced experimental rigor and benefited research on dietary supplement health effects.

Effects of 12-Week Multivitamin and Omega-3 Supplementation on Micronutrient Levels and Red Blood Cell Fatty Acids in Pre-menopausal Women

The purpose of this study was to validate the efficacy of a customized vitamin-mineral supplement on blood biomarkers in pre-menopausal females. Women (21-40 years old) who were apparently healthy were recruited from the local community (ClinicalTrials.gov trial registration NCT03828097). Pretesting (PRE) occurred in the morning 5 ± 2 days following each participant's menses and involved a fasted blood draw, body mass assessment, and blood pressure assessment. Participants were then randomly assigned in a double-blinded fashion to either the multivitamins (MV) (n = 43) or placebo group (n = 51). Participants consumed two capsules per day with breakfast for 12 weeks. Following the trial, participants reported to the laboratory for POST assessments, which replicated PRE procedures. Red blood cell fatty acid and serum micronutrient analyses were performed in a blinded fashion at hematology laboratories. A group × time interaction was observed for serum vitamin D levels (p < 0.001). MV increased levels from PRE to POST (+43.7%, p < 0.001), whereas no change occurred in the placebo group. Additionally, 78% of MV participants at PRE exhibited inadequate vitamin D levels (<40 ng/dl), whereas only 30% exhibited levels below this threshold at POST. An interaction was also observed for serum folate levels (p < 0.001). MV increased serum folate from PRE to POST (p < 0.001), whereas no change occurred in the placebo group. Red blood cell omega-3 fatty acid content increased from PRE to POST in the MV group (p < 0.001) and placebo group (p < 0.05), although POST values were greater in the MV group (p < 0.001). An interaction was observed for serum HDL cholesterol levels (p = 0.047), and a non-significant increase in this variable from PRE to POST occurred in the MV group (p = 0.060). Four-day food recalls indicated MV increased intake of omega-3 fatty acids, vitamin D, folate, and other micronutrients. In summary, MV supplementation increased serum vitamin D, serum folate, and red blood cell omega-3 fatty acid levels. However, these data are limited to healthy females, and more research is needed to examine if MV can affect metabolic disturbances in individuals with micronutrient deficiencies.

Evolution of cocoa flavanol analytics: impact on reporting and cross-study comparison

Cocoa flavanols (CF) are a group of dietary bioactives that have been studied for their potential health benefits for over two decades. In this time, multiple methods for CF testing have evolved, introducing the potential for differences in reported CF content. The reliable characterization of CF content in food and test materials used in clinical studies is critical to comparisons of research studies over time, as well as critical to enabling the systematic reviews and meta-analyses required to support dietary recommendations of bioactives. In this work, we compared two analytical methods that have been widely applied to characterize materials used in clinical research and a method newly recognized by AOAC as the official method for CF analysis. Differences in accuracy of -36% to +20% were observed when comparing CF contents determined with these methods, supporting the notion that CF values determined across methods are not directly comparable. To address differences, a linear regression model was developed to predict CF values. This approach was cross-validated and directly applied to the conversion of CF values published in key scientific papers on the benefits of CF. This work provides a valid tool to compare CF values reported across these different methods and enables comparisons and interpretation of studies investigating the bioactivity of CF.

Overview of dietary assessment methods for measuring intakes of foods, beverages, and dietary supplements in research studies

Measuring the dietary intakes of individuals for research and monitoring purposes is notoriously challenging and is subject to both random and systematic measurement error. In this review, the strengths and limitations of current methods to assess dietary and supplemental exposures are described. Traditional methods of dietary assessment include food records, food frequency questionnaires, 24-hour recalls, and screening tools; digital and mobile methods that leverage technology are available for these traditional methods. Ultimately, the choice of assessment method is dependent upon the research question, the study design, sample characteristics, and the size of the sample, to name just a few. Despite their challenges, dietary assessment tools are an important dimension of nutrition research and monitoring.

Genotype-guided dietary supplementation in precision nutrition

Achieving adequate micronutrient status, while avoiding deficiencies, represents a challenge for people globally. Consequently, many individuals resort to oral nutrient supplementation (ONS) in order to correct suboptimal dietary intakes. Advances in the fields of nutrigenetics and nutritional genomics have identified differences in response to micronutrient supplementation according to genetic makeup, adding dietary supplement use to the clinician's toolkit in the precision nutrition era. This review focuses on published evidence linking genetic variants to the responses associated with some of the most popular dietary supplements. With an increasing number of health professionals becoming involved in the prescription of ONS, identifying and matching individuals to the appropriate dietary supplement according to their genotype is important for achieving optimal health benefits and micronutrient equilibrium, while reducing the adverse events and financial costs often associated with excessive ONS.

Circulatory and Urinary B-Vitamin Responses to Multivitamin Supplement Ingestion Differ between Older and Younger Adults

Multivitamin and mineral (MVM) supplements are frequently used amongst older populations to improve adequacy of micronutrients, including B-vitamins, but evidence for improved health outcomes are limited and deficiencies remain prevalent. Although this may indicate poor efficacy of supplements, this could also suggest the possibility for altered B-vitamin bioavailability and metabolism in older people. This open-label, single-arm acute parallel study, conducted at the Liggins Institute Clinical Research Unit in Auckland, compared circulatory and urinary B-vitamer responses to MVM supplementation in older (70.1 ± 2.7 y, n = 10 male, n = 10 female) compared to younger (24.2 ± 2.8 y, n = 10 male, n = 10 female) participants for 4 h after the ingestion of a single dose of a commercial MVM supplement and standardized breakfast. Older adults had a lower area under the curve (AUC) of postprandial plasma pyridoxine (p = 0.02) and pyridoxal-5′phosphate (p = 0.03) forms of vitamin B₆ but greater 4-pyridoxic acid AUC (p = 0.009). Urinary pyridoxine and pyridoxal excretion were higher in younger females than in older females (time × age × sex interaction, p < 0.05). Older adults had a greater AUC increase in plasma thiamine (p = 0.01), riboflavin (p = 0.009), and pantothenic acid (p = 0.027). In older adults, there was decreased plasma responsiveness of the ingested (pyridoxine) and active (pyridoxal-5′phosphate) forms of vitamin B₆, which indicated a previously undescribed alteration in either absorption or subsequent metabolic interconversion. While these findings cannot determine whether acute B₆ responsiveness is adequate, this difference may have potential implications for B₆ function in older adults. Although this may imply higher B vitamin substrate requirements for older people, further work is required to understand the implications of postprandial differences in availability.

A Review of Analytical Methods for Calcium Salts and Cholecalciferol in Dietary Supplements

Dietary supplements composed by the combination of a calcium salt with cholecalciferol (vitamin D₃) are widely used for improving bone health in conditions caused by the deficiency of these compounds in the body. Historically, these supplements have been linked to quality and safety issues. In the case of calcium salts, the presence of potentially toxic contaminants such as lead (Pb) has already been alerted by health authorities from different countries. Meanwhile, cholecalciferol is very unstable under inadequate manufacturing and storage conditions. The content of both compounds in commercial dietary supplements is often found to be in disagreement with the label claims, which can lead to a deficient or excessive nutrient intake by consumers. In this scenario, analyzing these compounds is still a difficult and time-consuming task, which usually requires specific pretreatment procedures and multiple analytical methods due to the inorganic nature of calcium and the organic nature of cholecalciferol. Therefore, this article reviews the analytical methods, described in official compendia and scientific literature, for the determination of calcium salts and cholecalciferol in dietary supplement formulations. We also approached the sample preparation procedures highly required due to the matrix complexity of these materials.

Expired probiotics: what is really in your cabinet?

The popularity of using probiotics has surged, since they became widely accepted as safe and help improve general health. Inevitably, some of these products are used after expiration when microbial cell viability is below the recommended effective dose. Given that probiotics must be live microorganisms administered in adequate amounts, the aim of this study was to measure viability in expired products and assess how packaging and storage conditions impact efficacy, if at all. Thirty-three expired probiotic products were evaluated, of which 26 were stored in conditions recommended by the manufacturer. The viable microbial cells were enumerated and representative isolates identified by 16S and internally transcribed spacer rRNA gene sequencing. While the products had a mean past expiration time of 11.32 (1-22) years, 22 still had viable contents, and 5 were within or above the original product cell count claim. Product formulation and the number of species present did not appear to impact the stability of the products. However, overall packaging type, storage conditions and time since expiry were found to affect viability. All products with viable cells had the strain stipulated on the label. Despite some selected probiotic products retaining viability past their expiry date (indicating long-term storage is possible), the total counts were mostly well below that required for efficacious use as recommended by the manufacturer. Consuming expired probiotics may not yield the benefits for which they were designed.

An educational intervention improved knowledge of dietary supplements in college students

BACKGROUND

We have previously reported on the prevalence of dietary supplements among college students; it was deduced that their intake of supplements increased according to their grade (i.e., 13.1% in the first grade to 20.5% in the sixth grade). We also reported that some students had experienced adverse events in Japan due to their intake of these supplements. However, awareness of dietary supplements among college students remains limited, even among pharmaceutical students. Being appropriately educated about them is important for pharmaceutical students, both for themselves as well as for their future careers as pharmacists.

METHODS

We conducted a lecture-based educational intervention about dietary supplements on 328 college students in Japan-184 from pharmaceutical science and 144 from environmental science or food and life science disciplines. The purpose of this study was to evaluate the effects of an educational intervention on college students' understanding of dietary supplements. The intervention involved a lecture that covered the quality of dietary supplements, how they differed from drugs, and a summary of their adverse events. The lecture was evaluated using a 14-question questionnaire. We then compared the pre- and post-intervention responses to the same questionnaire using a Wilcoxon signed-rank test. The questions were assessed using a Likert scale that ranged from "strongly agree" to "strongly disagree"; the latter being the preferred answer.

RESULTS

Before the intervention had taken place, the students' understanding of dietary supplements was shown to be deficient. Conversely, post-intervention, their knowledge levels had significantly improved, especially concerning agreement on whether "Dietary supplements are safe because they are just food items". Pre-intervention, 2.7% strongly agreed and 37.5% agreed; post-intervention, 1.2% strongly agreed and 15.6% agreed. On whether "Dietary supplements made from natural ingredients or herbs are safe", at the pre-intervention stage 2.8% strongly agreed and 44.0% agreed and post-intervention, 2.2% strongly agreed and 16.9% agreed. On whether "Dietary supplements made from food items are safe", 4.0% strongly agreed and 43.6% agreed pre-intervention and 0.9% strongly agreed and 16.6% agreed post-intervention. Despite there being a greater number of pharmaceutical students who had a correct understanding of dietary supplements before the intervention, these students still showed improvement after the lecture.

CONCLUSION

An intervention in the form of a single educational lecture has the capacity to improve college students' understanding of dietary supplements. It is important for pharmacists to be appropriately educated about dietary supplements when they consult with patients. We will evaluate the long-term effects of the intervention on the alumni (pharmacists) in a subsequent study.

Comparison of 4 Methods to Assess the Prevalence of Use and Estimates of Nutrient Intakes from Dietary Supplements among US Adults

BACKGROUND

Accurate and reliable methods to assess prevalence of use of and nutrient intakes from dietary supplements (DSs) are critical for research, clinical practice, and public health monitoring. NHANES has been the primary source of DS usage patterns using an in-home inventory with a frequency-based DS and Prescription Medicine Questionnaire (DSMQ), but little is known regarding DS information obtained from 24-h dietary recalls (24HRs).

METHODS

The objectives of this analysis were to compare results from 4 different methods for measuring DS use constructed from two data collection instruments (i.e., DSMQ and 24HR) and to determine the most comprehensive method for measuring the prevalence of use and estimating nutrient intakes from DS for selected nutrients. NHANES 2011-2014 data from US adults (aged ≥19 y; n = 11,451) were used to examine the 4 combinations of methods constructed for measuring the prevalence of use of and amount of selected nutrients from DSs (i.e., riboflavin, vitamin D, folate, magnesium, calcium): 1) DSMQ, 2) 24HR day 1, 3) two 24HRs (i.e., mean), and 4) DSMQ or at least one 24HR.

RESULTS

Half of US adults reported DS use on the DSMQ (52%) and on two 24HRs (mean of 49%), as compared with a lower prevalence of DS use when using a single 24HR (43%) and a higher (57%) prevalence when combining the DSMQ with at least one 24HR. Mean nutrient intake estimates were highest using 24HR day 1. Mean supplemental calcium from the DSMQ or at least one 24HR was 372 mg/d, but 464 mg/d on the 24HR only. For vitamin D, the estimated intakes per consumption day were higher on the DSMQ (46 μg) and the DSMQ or at least one 24HR (44 μg) than those on the 24HR day 1 (32 μg) or the mean 24HR (31 μg). Fewer products were also classed as a default or reasonable match on the DSMQ than on the 24HR.

CONCLUSIONS

A higher prevalence of use of DSs is obtained using frequency-based methods, whereas higher amounts of nutrients are reported from a 24HR. The home inventory results in greater accuracy for products reported. Collectively, these findings suggest that combining the DSMQ with at least one 24HR (i.e., DSMQ or at least one 24HR) is the most comprehensive method for assessing the prevalence of and estimating usual intake from DSs in US adults.This trial was registered at clinicaltrials.gov as NCT03400436.

Bacteria increase host micronutrient availability: mechanisms revealed by studies in C. elegans

Micronutrients cannot be synthesized by humans and are obtained from three different sources: diet, gut microbiota, and oral supplements. The microbiota generates significant quantities of micronutrients, but the contribution of these compounds to total uptake is unclear. The role of bacteria in the synthesis and uptake of micronutrients and supplements is widely unexplored and may have important implications for human health. The efficacy and safety of several micronutrient supplements, including folic acid, have been questioned due to some evidence of adverse effects on health. The use of the simplified animal-microbe model, Caenorhabditis elegans, and its bacterial food source, Escherichia coli, provides a controllable system to explore the underlying mechanisms by which bacterial metabolism impacts host micronutrient status. These studies have revealed mechanisms by which bacteria may increase the bioavailability of folic acid, B12, and iron. These routes of uptake interact with bacterial metabolism, with the potential to increase bacterial pathogenesis, and thus may be both beneficial and detrimental to host health.

Environmental Selenium and Human Health: an Update

PURPOSE OF REVIEW

Selenium, a trace element, is ubiquitous in the environment. The main source of human exposure is diet. Despite its nutritional benefits, it is one of the most toxic naturally occurring elements. Selenium deficiency and overexposure have been associated with adverse health effects. Its level of toxicity may depend on its chemical form, as inorganic and organic species have distinct biological properties.

RECENT FINDINGS

Nonexperimental and experimental studies have generated insufficient evidence for a role of selenium deficiency in human disease, with the exception of Keshan disease, a cardiomyopathy. Conversely, recent randomized trials have indicated that selenium overexposure is positively associated with type 2 diabetes and high-grade prostate cancer. In addition, a natural experiment has suggested an association between overexposure to inorganic hexavalent selenium and two neurodegenerative diseases, amyotrophic lateral sclerosis and Parkinson's disease. Risk assessments should be revised to incorporate the results of studies demonstrating toxic effects of selenium. Additional observational studies and secondary analyses of completed randomized trials are needed to address the uncertainties regarding the health risks of selenium exposure.

Weighing the risks of high intakes of selected micronutrients compared with the risks of deficiencies

Several intervention strategies are available to reduce micronutrient deficiencies, but uncoordinated implementation of multiple interventions may result in excessive intakes. We reviewed relevant data collection instruments and available information on excessive intakes for selected micronutrients and considered possible approaches for weighing competing risks of intake above tolerable upper intake levels (ULs) versus insufficient intakes at the population level. In general, population-based surveys in low- and middle-income countries suggest that dietary intakes greater than the UL are uncommon, but simulations indicate that fortification and supplementation programs could lead to high intakes under certain scenarios. The risk of excessive intakes can be reduced by considering baseline information on dietary intakes and voluntary supplement use and continuously monitoring program coverage. We describe a framework for comparing risks of micronutrient deficiency and excess, recognizing that critical information for judging these risks is often unavailable. We recommend (1) assessing total dietary intakes and nutritional status; (2) incorporating rapid screening tools for routine monitoring and surveillance; (3) addressing critical research needs, including evaluations of the current ULs, improving biomarkers of excess, and developing methods for predicting and comparing risks and benefits; and (4) ensuring that relevant information is used in decision-making processes.

Best Practices for Dietary Supplement Assessment and Estimation of Total Usual Nutrient Intakes in Population-Level Research and Monitoring

The use of dietary supplements (DS) is pervasive and can provide substantial amounts of micronutrients to those who use them. Therefore when characterizing dietary intakes, describing the prevalence of inadequacy or excess, or assessing relations between nutrients and health outcomes, it is critical to incorporate DS intakes to improve exposure estimates. Unfortunately, little is known about the best methods to assess DS, and the structure of measurement error in DS reporting. Several characteristics of nutrients from DS are salient to understand when comparing to those in foods. First, DS can be consumed daily or episodically, in bolus form and can deliver discrete and often very high doses of nutrients that are not limited by energy intakes. These characteristics contribute to bimodal distributions and distributions severely skewed to the right. Labels on DS often provide nutrient forms that differ from those found in conventional foods, and underestimate analytically derived values. Finally, the bioavailability of many nutrient-containing DS is not known and it may not be the same as the nutrients in a food matrix. Current methods to estimate usual intakes are not designed specifically to handle DS. Two temporal procedures are described to refer to the order that nutrient intakes are combined relative to usual intake procedures, referred to as a "shrinking" the distribution to remove random error. The "shrink then add" approach is preferable to the "add then shrink" approach when users and nonusers are combined for most research questions. Stratifying by DS before usual intake methods is another defensible option. This review describes how to incorporate nutrient intakes from DS to usual intakes from foods, and describes the available methods and fit-for-purpose of different analytical strategies to address research questions where total usual intakes are of interest at the group level for use in nutrition research and to inform policy decisions. Clinical Trial Registry: NCT03400436.

Iodine Content of the Best-Selling United States Adult and Prenatal Multivitamin Preparations

BACKGROUND

Iodine is essential for thyroid hormone production and fetal development. Even mild maternal iodine deficiency in gestation may be associated with impaired child neurodevelopment. Iodine requirements increase during pregnancy and lactation. Supplements containing 150 μg/day are recommended by the American Thyroid Association for all U.S. women who are pregnant, lactating, or planning pregnancy. The contribution of multivitamin supplements as an iodine source for pregnant and nonpregnant US adults has not been well studied. This study aimed to understand better the contribution of the top-selling adult multivitamins (AMV) and prenatal multivitamins (PMV) to iodine nutrition in the United States.

METHODS

Product names, dollar sales, unit and volume sales, and recommended daily intakes of the top-selling 99 AMV and 60 PMV from July 2016 to July 2017 were obtained from Information Resources, Inc. Iodine content and source were determined from product labels. After excluding private-label brands and unavailable product labels, a final sample of 89 AMV and 59 PMV was analyzed.

RESULTS

Of the 89 AMV, 74.2% contained iodine. The median (range) iodine content of AMV was 150 μg (38-150 μg) per daily serving. Over the study period, 8,924,371,955 AMV doses were sold, of which 84.8% contained iodine. Thirty-four (57.6%) of the 59 PMV contained iodine, with a median (range) iodine content of 150 μg (25-290 μg) per daily serving. Over the study period, 466,927,559 PMV doses were sold, of which 76.8% contained iodine. All iodine-containing AMV used potassium iodine as an iodine source. Of iodine-containing PMV, 73.5% used potassium iodide, 23.5% kelp, and 2.9% inactivated Saccharomyces cerevisiae as an iodine source.

CONCLUSIONS

During the one-year study period, a higher proportion of AMV doses than PMV doses contained iodine. Some PMV but no AMV included sources of iodine known to be highly variable. The median iodine content of the top-selling AMV and PMV was at the recommended 150 μg daily intake, but the range remains wide. Twenty-four percent of PMV doses sold did not contain iodine. More effort is needed to ensure adequate iodine content in prenatal vitamins for women who are pregnant, lactating, or planning pregnancy.

Current regulatory guidelines and resources to support research of dietary supplements in the United States

The U.S. Dietary Supplement Health and Education Act (DSHEA) established the regulatory framework for dietary supplements as foods through the Food and Drug Administration (FDA). DSHEA outlined the legal definition, labeling requirements, and process for adverse event reporting for dietary supplements. FDA also issued formal guidance on current Good Manufacturing Practice to ensure that processes for preparation, packaging, labeling, and storage of supplements and ingredients are documented and meet specifications to ensure purity, composition, and strength. However, efficacy of dietary supplements is not required under U.S. law. Despite regulations to improve the marketplace, many challenges remain; as a result, the quality and safety of products available can be highly variable, especially for botanical and herbal products. The ability of regulators to successfully carry out their mission is hampered by the sheer number of products and manufacturing facilities and a lack of analytical methods for all ingredients and products in the marketplace, this is especially difficult for herbal and botanical dietary supplements. Safety issues continue to exist such as adulteration and contamination, especially with specific product types (i.e. body building, sexual enhancement). Thus, a need remains for continued efforts and improved techniques to assess the quality of dietary supplements, especially with regard to purity, bioavailability, and safety. This review will highlight the existing American regulatory framework for dietary supplements and will describe the remaining regulatory barriers to ensuring that safe and high-quality dietary supplements are offered in the marketplace.

Dietary Supplement Ingredient Database (DSID) and the Application of Analytically Based Estimates of Ingredient Amount to Intake Calculations

OBJECTIVE

We describe the purpose of the Dietary Supplement Ingredient Database (DSID), the statistical methodology underlying online calculators of analytically verified supplement content estimates, and the application and significance of DSID label adjustments in nutritional epidemiology.

BACKGROUND AND HISTORY

During dietary supplement (DS) manufacturing, many ingredients are added at higher than declared label amounts, but overages are not standardized among manufacturers. As a result, researchers may underestimate nutrient intakes from DSs. The DSID provides statistical tools on the basis of the results of chemical analysis to convert label claims into analytically predicted ingredient amounts. These adjustments to labels are linked to DS products reported in NHANES.

RATIONALE

Tables summarizing the numbers of NHANES DS products with ingredient overages and below label content show the importance of DSID adjustments to labels for accurate intake calculations.

RECENT DEVELOPMENTS

We show the differences between analytically based estimates and labeled content for vitamin D, calcium, iodine, caffeine, and omega-3 (n-3) fatty acids and their potential impact on the accuracy of intake assessments in large surveys. Analytical overages >20% of label levels are predicted for several nutrients in 50-99% of multivitamin-mineral products (MVMs) reported in NHANES: for iodine and selenium in adult MVMs, for iodine and vitamins D and E in children's MVMs, and for iodine, chromium, and potassium in nonprescription prenatal MVMs. Predicted overages of 10-20% for calcium can be applied to most MVMs and overages >10% for folic acid in the vast majority of adult and children's MVMs.

FUTURE DIRECTIONS

DSID studies are currently evaluating ingredient levels in prescription prenatal MVMs and levels of constituents in botanical DSs.

CONCLUSIONS

We estimate that the majority of MVM products reported in NHANES have significant overages for several ingredients. It is important to account for nonlabeled additional nutrient exposure from DSs to better evaluate nutritional status in the United States.

Characteristics and Challenges of Dietary Supplement Databases Derived from Label Information

Launched in 2008, the Dietary Supplement Label Database (DSLD) permits the search of any term that appears anywhere on product labels. Since then, the database's search and download features have been periodically improved to enhance use for researchers and consumers. In this review, we describe how to customize searches and identify products and ingredients of interest to users in the DSLD, and provide the limitations of working with information derived from dietary supplement product labels. This article describes how data derived from information printed on product labels are entered and organized in the DSLD. Among the challenges are determining the chemical forms, types of extract, and amounts of dietary ingredients, especially when these are components of proprietary blends. The FDA announced new dietary supplement labeling regulations in May 2016. The 2017 DSLD has been updated to reflect them. These new regulations and examples cited in this article refer to this redesigned version of the DSLD. Search selection characteristics such as for product type and intended user group are as described in FDA guidance and regulations for dietary supplements. For this reason, some age groups (such as teens and seniors) and marketing recommendations for use (e.g., weight loss, performance, and other disease- or condition-specific claims) are not included in the search selections. The DSLD user interface features will be revised periodically to reflect regulatory and technologic developments to enhance user experience. A comprehensive database derived from analytically verified data on composition would be preferable to label data, but is not feasible for technical, logistic, and financial reasons. Therefore, a database derived from information printed on product labels is the only practical option at present for researchers, clinicians, and consumers interested in the composition of these products.

Challenges in Developing Analytically Validated Laboratory-Derived Dietary Supplement Databases

The Dietary Supplement Label Database (DSLD) is sponsored by the Office of Dietary Supplements (ODS) and the National Library of Medicine (NLM). It provides a searchable, free database of the contents of ∼65,000 supplement labels. A companion database of analytically verified product labels [the Dietary Supplement Ingredient Database (DSID)] was created by ODS, NLM, and the USDA. There are considerable challenges to populating both databases, but the DSID faces unique analytic chemistry challenges. This article describes the challenges to creating analytically verified marketplace surveys of dietary supplement (DS) product content claims for inclusion in public databases. Nutritionists and public health scientists require information on actual exposures to DS constituents because labeled content may not match labeled product content. Analytic verification of composition of DSs provides a link to actual exposure. A public database of analytically derived DS content was developed to provide more accurate estimates of dietary intake in population-based epidemiologic studies. The DSID has conducted surveys of several types of vitamin- and mineral-containing DSs. Results showing label content claims as analytically derived values are available in the current DSID. A recent pilot project explored the feasibility of adding botanical DS products to the DSID. Candidates for future botanical DSID studies will be based on sales volume, potential public health impacts, and the availability of validated analytic methods and reference materials. Databases like DSID and the DSLD are essential for researchers and clinicians to evaluate dietary ingredient intakes in population-based epidemiologic studies. Together, these databases provide a picture of the DS marketplace. The DSID provides an analytic survey of marketed DSs. However, selection of future botanical supplements for DSID evaluation involves analytic challenges. Even when appropriate resources are available, method selection and data evaluation are resource- and time-consuming.

A bacterial route for folic acid supplementation

Background

To prevent folate deficiencies, many countries supplement various foodstuffs with folic acid. This compound is a synthetic oxidised folate that differs from naturally occurring reduced folates in its metabolism and uptake. Notably, safety reviews of folic acid supplementation have not considered interactions with gut bacteria. Here, we use the Caenorhabditis elegans – Escherichia coli animal– microbe model to examine a possible bacterial route for folic acid uptake. It has been assumed that supplements are taken up directly by the worm, especially because E. coli is unable to take up folates. However, E. coli, like many other bacteria, can transport the folate breakdown product, para-aminobenzoate-glutamate (PABA-glu), via AbgT and use it for bacterial folate synthesis. This pathway may impact host health because inhibition of bacterial folate synthesis increases C. elegans lifespan.

Results

Folic acid supplementation was found to rescue a C. elegans developmental folate-deficient mutant; however, a much higher concentration was required compared to folinic acid, a reduced folate. Unlike folinic acid, the effectiveness of folic acid supplementation was dependent on the E. coli gene, abgT, suggesting a bacterial route with PABA-glu uptake by E. coli as a first step. Surprisingly, we found up to 4% PABA-glu in folic acid preparations, including in a commercial supplement. Via breakdown to PABA-glu, folic acid increases E. coli folate synthesis. This pathway restores folate synthesis in a bacterial mutant defective in PABA synthesis, reversing the ability of this mutant to increase C. elegans lifespan.

Conclusions

Folic acid supplementation in C. elegans occurs chiefly indirectly via bacterial uptake of breakdown products via E. coli AbgT, and can impact C. elegans development and longevity. Examining how folic acid supplementation affects bacterial folate synthesis in the human gut may help us to better understand the safety of folic acid supplementation.

Electronic supplementary material

The online version of this article (10.1186/s12915-018-0534-3) contains supplementary material, which is available to authorized users.

Trends in calcium supplementation, National Health and Nutrition Examination Survey (NHANES) 1999-2014

BACKGROUND

Long-term outcomes of supplemental calcium are inadequately understood. Recent research suggests that calcium from supplements may not be entirely free from unintended health consequences. Consequently, it is important to understand patterns and trends in use of calcium supplements.

OBJECTIVE

To report trends in supplemental calcium intake between 1999 and 2014, using NHANES data, overall and stratified by sex, race/ethnicity and age.

METHODS

A total of 42,038 adult NHANES participants were included in this analysis. For each survey period, we calculated the prevalence of calcium supplement use exceeding the Estimated Average Requirement (EAR) and Tolerable Upper Intake Levels (UL), and mean daily supplemental calcium dose among calcium-containing supplement users. Sample weights were applied. Linear regression was used to examine trends.

RESULTS

Overall, the prevalence of calcium supplement use at a dose ≥EAR increased between 1999 and 2000 and 2013-2014, from 2.5% (95% CI: 1.9-3.3%) to 4.6% (3.8-5.5%). Use ≥EAR peaked in 2003-2004 at 6.7% (5.3-8.5%) (p-quadratic trend<0.001). Mean supplemental calcium intake peaked in 2007-2008, thereafter decreasing (p-quadratic trend<0.001). The overall prevalence of intake ≥UL from supplemental calcium in 2013-2014 was 0.4% (0.2-0.8%). Use of supplemental calcium ≥UL peaked during 2007-2008 at 1.2% (0.7-2.0%). In all time periods, supplemental calcium intake tended to be greater among women, non-Hispanic whites and adults >60years.

CONCLUSIONS

We described the prevalence of U.S. adults consuming supplemental calcium ≥UL and ≥ EAR. While few were consuming supplemental calcium ≥UL, consumption ≥EAR was not uncommon, especially among women, non-Hispanic whites and older adults.

Prevalence of inadequate micronutrient intakes of Canadian long-term care residents

This study determines the prevalence of inadequate micronutrient intakes consumed by long-term care (LTC) residents. This cross-sectional study was completed in thirty-two LTC homes in four Canadian provinces. Weighed and estimated food and beverage intake were collected over 3 non-consecutive days from 632 randomly selected residents. Nutrient intakes were adjusted for intra-individual variation and compared with the Dietary Reference Intakes. Proportion of participants, stratified by sex and use of modified (MTF) or regular texture foods, with intakes below the Estimated Average Requirement (EAR) or Adequate Intake (AI), were identified. Numbers of participants that met these adequacy values with use of micronutrient supplements was determined. Mean age of males (n 197) was 85·2 (sd 7·6) years and females (n 435) was 87·4 (sd 7·8) years. In all, 33 % consumed MTF; 78·2 % (males) and 76·1 % (females) took at least one micronutrient pill. Participants on a MTF had lower intake for some nutrients (males=4; females=8), but also consumed a few nutrients in larger amounts than regular texture consumers (males=4; females =1). More than 50 % of participants in both sexes and texture groups consumed inadequate amounts of folate, vitamins B6, Ca, Mg and Zn (males only), with >90 % consuming amounts below the EAR/AI for vitamin D, E, K, Mg (males only) and K. Vitamin D supplements resolved inadequate intakes for 50-70 % of participants. High proportions of LTC residents have intakes for nine of twenty nutrients examined below the EAR or AI. Strategies to improve intake specific to these nutrients are needed.

Development of Databases on Iodine in Foods and Dietary Supplements

Iodine is an essential micronutrient required for normal growth and neurodevelopment; thus, an adequate intake of iodine is particularly important for pregnant and lactating women, and throughout childhood. Low levels of iodine in the soil and groundwater are common in many parts of the world, often leading to diets that are low in iodine. Widespread salt iodization has eradicated severe iodine deficiency, but mild-to-moderate deficiency is still prevalent even in many developed countries. To understand patterns of iodine intake and to develop strategies for improving intake, it is important to characterize all sources of dietary iodine, and national databases on the iodine content of major dietary contributors (including foods, beverages, water, salts, and supplements) provide a key information resource. This paper discusses the importance of well-constructed databases on the iodine content of foods, beverages, and dietary supplements; the availability of iodine databases worldwide; and factors related to variability in iodine content that should be considered when developing such databases. We also describe current efforts in iodine database development in the United States, the use of iodine composition data to develop food fortification policies in New Zealand, and how iodine content databases might be used when considering the iodine intake and status of individuals and populations.

Is Nutrient Content and Other Label Information for Prescription Prenatal Supplements Different from Nonprescription Products?

BACKGROUND

Prenatal supplements are often recommended to pregnant women to help meet their nutrient needs. Many products are available, making it difficult to choose a suitable supplement because little is known about their labeling and contents to evaluate their appropriateness.

OBJECTIVE

To determine differences between prescription and nonprescription prenatal supplements available in the United States regarding declared nutrient and nonnutrient ingredients and the presence of dosing and safety-related information.

DESIGN

Using two publicly available databases with information about prenatal supplement products, information from prescription and nonprescription product labels were extracted and evaluated. For the 82 prescription and 132 nonprescription products, declared label amounts of seven vitamins and minerals, docosahexaenoic acid (DHA), the presence of other nonnutrient components, and the presence of key safety and informational elements as identified in two Department of Health and Human Services Office of Inspector General (OIG)'s 2003 reports were compiled and compared.

RESULTS

Compared with nonprescription products, prescription products contained significantly fewer vitamins (9±0.2 vs 11±0.3; P≤0.05) and minerals (4±0.1 vs 8±0.3; P≤0.05). Declared amounts of folic acid were higher in prescription products, whereas vitamin A, vitamin D, iodine, and calcium were higher in the nonprescription products. Amounts of iron, zinc, and DHA were similar. Virtually all products contained levels of one or more nutrients that exceeded the Recommended Dietary Allowances for pregnant and/or lactating women. Product type also influenced ingredients added. Fewer prescription products contained botanical ingredients (6% prescription vs 33% nonprescription) and probiotics (2% prescription vs 8% nonprescription). Only prescription products contained the stool softener docusate sodium.

CONCLUSIONS

Our analysis of prenatal supplements indicates that prescription and nonprescription supplements differ in terms of declared composition and nutrient strength, but have labels that are similarly sparse regarding aspects of use such as dosing information.