ABSTRACT
Immune health products represent approximately 10% of all US dietary supplement sales. Claims made on products to support or boost the immune system are attractive to the otherwise healthy consumer who may or may not be experiencing certain life stressors. The purpose of this systematic review is to critically evaluate the purported benefits and/or potential harms of select dietary supplement ingredients frequently listed on the labels of products having immune health or related market claims. With a focus on resilience, research questions were related to whether dietary supplement ingredients are efficacious in preserving and protecting immune health in healthy individuals; and when faced with a stressor, whether taking a supplement prophylactically can assist in maintaining health and resisting or bouncing back more quickly. Thirty-nine randomized controlled studies involving populations including children, adults and seniors exposed to stressors, such as air travel, intense exercise, academic stress, and/or exposure to winter weather, met eligibility criteria. The studies included eight of the 27 supplement ingredients identified through a market-driven scoping review. Those ingredients used in single ingredient products were echinacea, elderberry, garlic, vitamin A, vitamin C, vitamin D, vitamin E, and zinc. Whereas some studies may point to evidence for benefit, specific gaps preclude the authors from making firm statements with regard to the overall evidence-base for these products and ingredients and in answering the research questions. As we move toward a vision of health promotion and resilience rather than a sole focus on disease prevention and treatment, further work in this area of dietary supplements is of utmost importance.
Subject(s)
Biological Products , Dietary Supplements , Adult , Child , Humans , Vitamins , Exercise , Immune SystemABSTRACT
AIMS: This study aimed to: 1) investigate sex differences in heat-induced mitochondrial dysfunction, ROS production, and skeletal muscle injury in mice; 2) evaluate whether curcumin and astaxanthin, alone or together, would prevent those heat-induced changes. MAIN METHODS: Male and female C57BL/6J mice were treated with curcumin and astaxanthin for 10 days, then exposed to 39.5 °C heat for up to 3 h. Heat-induced hyperthermia, changes in mitochondrial morphology and function, and oxidative damage to skeletal muscle were evaluated. KEY FINDINGS: Although female mice had a slightly higher basal core body temperature (Tc) than male mice, peak Tc during heat exposure was significantly lower in females than in males. Heat increased ROS levels in skeletal muscle in both sexes; interestingly, the increases in ROS were greater in females than in males. Despite the above-mentioned differences, heat induced similar levels of mitochondrial fragmentation and membrane potential depolarization, caspase 3/7 activation, and injury in male and female skeletal muscle. Individual treatment of curcumin or astaxanthin did not affect basal and peak Tc but prevented heat-induced mitochondrial dysfunction, ROS increases, and apoptosis in a dose-dependent manner. Moreover, a low-dose combination of curcumin and astaxanthin, which individually showed no effect, reduced the heat-induced oxidative damage to skeletal muscle. SIGNIFICANCE: Both male and female mice can develop mitochondrial dysfunction and oxidative stress in skeletal muscle when exposed to heat stress. High doses of either curcumin or astaxanthin limit heat-induced skeletal muscle injury, but a low-dose combination of these ingredients may increase their efficacy.
Subject(s)
Curcumin/pharmacology , Heat-Shock Response , Hyperthermia, Induced/adverse effects , Muscle, Skeletal/drug effects , Muscular Diseases/drug therapy , Reactive Oxygen Species/metabolism , Animals , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Diet , Female , Male , Mice , Mice, Inbred C57BL , Muscle, Skeletal/injuries , Muscle, Skeletal/metabolism , Muscle, Skeletal/pathology , Muscular Diseases/etiology , Muscular Diseases/metabolism , Muscular Diseases/pathology , Oxidative Stress , Protective Agents/pharmacology , Xanthophylls/pharmacologySubject(s)
COVID-19/epidemiology , Magnesium Deficiency/epidemiology , Magnesium/physiology , Aging , COVID-19/prevention & control , Cardiovascular Diseases/epidemiology , Comorbidity , Congresses as Topic , Disease Susceptibility , Humans , Immune System/physiology , Inflammation/epidemiology , Magnesium Deficiency/therapy , Metabolic Diseases/epidemiology , Neoplasms/epidemiology , Obesity/epidemiology , Research , Societies, ScientificABSTRACT
The US Dietary Guidelines for Americans (DGA) provide dietary recommendations to meet nutrient needs, promote health, and prevent disease. Despite 40 years of DGA, the prevalence of under-consumed nutrients continues in the US and globally, although dietary supplement use can help to fill shortfalls. Nutrient recommendations are based on Dietary Reference Intakes (DRIs) to meet the nutrient requirements for nearly all (97 to 98 percent) healthy individuals in a particular life stage and gender group and many need to be updated using current evidence. There is an opportunity to modernize vitamin and mineral intake recommendations based on biomarker or surrogate endpoint levels needed to 'prevent deficiency' with DRIs based on ranges of biomarker or surrogate endpoints levels that support normal cell/organ/tissue function in healthy individuals, and to establish DRIs for bioactive compounds. We recommend vitamin K and Mg DRIs be updated and DRIs be established for lutein and eicosapentaenoic and docosahexaenoic acid (EPA + DHA). With increasing interest in personalized (or precision) nutrition, we propose greater research investment in validating biomarkers and metabolic health measures and the development and use of inexpensive diagnostic devices. Data generated from such approaches will help elucidate optimal nutrient status, provide objective evaluations of an individual's nutritional status, and serve to provide personalized nutrition guidance.
Subject(s)
Health Promotion , Nutrition Policy/legislation & jurisprudence , Dietary Supplements , Fatty Acids, Omega-3 , Health Promotion/legislation & jurisprudence , Health Promotion/standards , Humans , Lutein , Nutritional Status , Recommended Dietary Allowances , United States , Vitamin KABSTRACT
Low magnesium intakes coupled with high calcium intakes and high calcium-to-magnesium (Ca:Mg) intake ratios have been associated with increased risk for multiple chronic conditions such as cardiovascular disease and metabolic syndrome, as well as some cancers (colorectal, prostate, esophageal), and total mortality. A high dietary Ca:Mg ratio (>2.60) may affect body magnesium status while, on the other hand, high intakes of magnesium could adversely impact individuals with an exceedingly low dietary Ca:Mg ratio (<1.70). Thus, a Ca:Mg ratio range of 1.70-2.60 (weight to weight) has been proposed as an optimum range. Data from NHANES surveys have shown the mean Ca:Mg intake ratio from foods alone for US adults has been >3.00 since 2000. One-third of Americans consume a magnesium supplement with a mean dose of 146 mg/d, and 35% of Americans consume a calcium supplement with a mean dose of 479 mg/d. Our review of Ca:Mg ratios in dietary supplements sold in the United States and listed in NIH's Dietary Supplement Label Database (DSLD) found a mean ratio of 2.90 across all calcium- and magnesium-containing products, with differences by product form. The ratios ranged from a low of 0.10 in liquid products to a high of 48.5 in powder products. Thirty-one percent of products fell below, 40.5% fell within, and 28.3% fell above the ratio range of 1.70-2.60. Our findings of calculated Ca:Mg ratios from dietary supplements coupled with food-intake data suggest that, in individuals with high calcium intakes from diet and/or supplements, magnesium supplementation may be warranted to establish a more favorable dietary Ca:Mg ratio in their total diet. Additional research may provide greater insight into whether the Ca:Mg ratio is a biomarker of interest for moderating chronic disease and which population groups may derive benefit from moderating that ratio.
Subject(s)
Calcium , Magnesium , Adult , Calcium, Dietary , Diet , Dietary Supplements , Humans , Male , Nutrition Surveys , United StatesABSTRACT
Background: Previous in vitro and in vivo studies indicate that enzymes that synthesize and metabolize vitamin D are magnesium dependent. Recent observational studies found that magnesium intake significantly interacted with vitamin D in relation to vitamin D status and risk of mortality. According to NHANES, 79% of US adults do not meet their Recommended Dietary Allowance of magnesium. Objectives: The aim of this study was to test the hypothesis that magnesium supplementation differentially affects vitamin D metabolism dependent on baseline 25-hydroxyvitamin D [25(OH)D] concentration. Methods: The study included 180 participants aged 40-85 y and is a National Cancer Institute independently funded ancillary study, nested within the Personalized Prevention of Colorectal Cancer Trial (PPCCT), which enrolled 250 participants. The PPCCT is a double-blind 2 × 2 factorial randomized controlled trial conducted in the Vanderbilt University Medical Center. Doses for both magnesium and placebo were customized based on baseline dietary intakes. Subjects were randomly assigned to treatments using a permuted-block randomization algorithm. Changes in plasma 25-hydroxyvitamin D3 [25(OH)D3], 25-hydroxyvitamin D2 [25(OH)D2], 1,25-dihydroxyvitamin D3, 1,25-dihydroxyvitamin D2, and 24,25-dihydroxyvitamin D3 [24,25(OH)2D3] were measured by liquid chromatography-mass spectrometry. Results: The relations between magnesium treatment and plasma concentrations of 25(OH)D3, 25(OH)D2, and 24,25(OH)2D3 were significantly different dependent on the baseline concentrations of 25(OH)D, and significant interactions persisted after Bonferroni corrections. Magnesium supplementation increased the 25(OH)D3 concentration when baseline 25(OH)D concentrations were close to 30 ng/mL, but decreased it when baseline 25(OH)D was higher (from â¼30 to 50 ng/mL). Magnesium treatment significantly affected 24,25(OH)2D3 concentration when baseline 25(OH)D concentration was 50 ng/mL but not 30 ng/mL. On the other hand, magnesium treatment increased 25(OH)D2 as baseline 25(OH)D increased. Conclusion: Our findings suggest that optimal magnesium status may be important for optimizing 25(OH)D status. This trial was registered at clinicaltrials.gov as NCT03265483.
Subject(s)
Magnesium/administration & dosage , Nutritional Status , Vitamin D/analogs & derivatives , Vitamin D/blood , 24,25-Dihydroxyvitamin D 3/blood , 25-Hydroxyvitamin D 2/blood , Aged , Calcifediol/blood , Calcitriol/blood , Dietary Supplements , Ergocalciferols/blood , Female , Humans , Kidney/physiopathology , Magnesium Deficiency/physiopathology , Male , Middle Aged , Placebos , Vitamin D Deficiency/physiopathologyABSTRACT
Objective: To describe the history, key features, recent enhancements, and common applications of the Dietary Supplement Label Database (DSLD). Background and History: Although many Americans use dietary supplements, databases of dietary supplements sold in the United States have not been widely available. The DSLD, an easily accessible public-use database was created in 2008 to provide information on dietary supplement composition for use by researchers and consumers. Rationale: Accessing current information easily and quickly is crucial for documenting exposures to dietary supplements because they contain nutrients and other bioactive ingredients that may have beneficial or adverse effects on human health. This manuscript details recent developments with the DSLD to achieve this goal and provides examples of how the DSLD has been used. Recent Developments: With periodic updates to track changes in product composition and capture new products entering the market, the DSLD currently contains more than 71,000 dietary supplement labels. Following usability testing with consumer and researcher user groups completed in 2016, improvements to the DSLD interface were made. As of 2017, both a desktop and mobile device version are now available. Since its inception in 2008, the use of the DSLD has included research, exposure monitoring, and other purposes by users in the public and private sectors. Future Directions: Further refinement of the user interface and search features to facilitate ease of use for stakeholders is planned. Conclusions: The DSLD can be used to track changes in product composition and capture new products entering the market. With over 71,000 DS labels it is a unique resource that policymakers, researchers, clinicians, and consumers may find valuable for multiple applications.
Subject(s)
Commerce , Databases, Factual , Dietary Supplements , Information Dissemination , Product Labeling , Humans , United StatesABSTRACT
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.
Subject(s)
Databases, Factual , Dietary Supplements/analysis , Dietary Supplements/standards , Food Labeling/standards , Humans , Laboratories , Minerals/administration & dosage , Minerals/analysis , Minerals/standards , Nutrition Surveys , Quality Control , United States , Vitamins/administration & dosage , Vitamins/analysis , Vitamins/standardsABSTRACT
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.
Subject(s)
Databases, Factual , Dietary Supplements , Food Labeling , Dietary Supplements/analysis , Food Labeling/legislation & jurisprudence , Food Labeling/standards , Food Labeling/statistics & numerical data , Humans , Legislation, Food , United States , United States Food and Drug AdministrationABSTRACT
PURPOSE OF REVIEW: To update advances in identifying factors affecting magnesium (Mg) status that assist in providing improved evidence-based clinical decision-making for assessing Mg status. RECENT FINDINGS: Findings from recent cohort studies, small randomized control trials, and multiple meta-analyses reinforce earlier work that serum Mg concentrations, urinary Mg excretion, and Mg dietary intakes are inversely associated with cardiovascular disease, chronic kidney disease, and diabetes. These studies indicate that the reference range for serum Mg needs updating, and that individuals with serum Mg in the range of 0.75-0.85âmmol/l and displaying changes in other factors associated with a low Mg status may be Mg deficient. Individuals with serum Mg concentrations below this range most likely are Mg deficient and, above this range, are most likely Mg sufficient. SUMMARY: The combined determination of serum Mg concentration, 24-h urinary Mg excretion, and dietary Mg intake is currently the most practical method to obtain a sound assessment of Mg status. The strong correlations of Mg deficiency with increased risk of several chronic diseases, some of which exist as comorbidities, indicate that Mg status should be ascertained in patients presenting such disorder.
Subject(s)
Magnesium/administration & dosage , Magnesium/blood , Magnesium/urine , Cardiovascular Diseases/blood , Cardiovascular Diseases/complications , Cardiovascular Diseases/prevention & control , Clinical Decision-Making , Diabetes Mellitus/blood , Diabetes Mellitus/prevention & control , Dietary Supplements , Evidence-Based Medicine , Humans , Magnesium Deficiency/blood , Magnesium Deficiency/complications , Magnesium Deficiency/drug therapy , Meta-Analysis as Topic , Randomized Controlled Trials as Topic , Renal Insufficiency, Chronic/blood , Renal Insufficiency, Chronic/complications , Renal Insufficiency, Chronic/prevention & controlABSTRACT
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.
Subject(s)
Dietary Supplements/standards , Drug Labeling/standards , Food Labeling/standards , Nonprescription Drugs/standards , Prescription Drugs/standards , Databases, Factual , Drug Labeling/methods , Female , Food Labeling/methods , Humans , Nutritive Value , Pregnancy , Prenatal Care , Prenatal Nutritional Physiological Phenomena , Recommended Dietary Allowances , United StatesABSTRACT
Multiple randomized controlled trials (RCTs) have assessed the effects of supplementation with eicosapentaenoic acid plus docosahexaenoic acid (omega-3 polyunsaturated fatty acids, commonly called fish oils) on the occurrence of clinical cardiovascular diseases. Although the effects of supplementation for the primary prevention of clinical cardiovascular events in the general population have not been examined, RCTs have assessed the role of supplementation in secondary prevention among patients with diabetes mellitus and prediabetes, patients at high risk of cardiovascular disease, and those with prevalent coronary heart disease. In this scientific advisory, we take a clinical approach and focus on common indications for omega-3 polyunsaturated fatty acid supplements related to the prevention of clinical cardiovascular events. We limited the scope of our review to large RCTs of supplementation with major clinical cardiovascular disease end points; meta-analyses were considered secondarily. We discuss the features of available RCTs and provide the rationale for our recommendations. We then use existing American Heart Association criteria to assess the strength of the recommendation and the level of evidence. On the basis of our review of the cumulative evidence from RCTs designed to assess the effect of omega-3 polyunsaturated fatty acid supplementation on clinical cardiovascular events, we update prior recommendations for patients with prevalent coronary heart disease, and we offer recommendations, when data are available, for patients with other clinical indications, including patients with diabetes mellitus and prediabetes and those with high risk of cardiovascular disease, stroke, heart failure, and atrial fibrillation.
Subject(s)
Cardiovascular Diseases/epidemiology , Cardiovascular Diseases/prevention & control , Dietary Supplements , Fatty Acids, Omega-3/administration & dosage , Fish Oils/administration & dosage , Atrial Fibrillation/etiology , Atrial Fibrillation/prevention & control , Cardiac Surgical Procedures/adverse effects , Cardiovascular Diseases/etiology , Cardiovascular Diseases/mortality , Diabetes Complications , Diabetes Mellitus/prevention & control , Heart Failure/prevention & control , Humans , Primary Prevention , Risk , Secondary Prevention , Stroke/prevention & controlABSTRACT
CONTEXT: Dietary supplements are widely used by military personnel and civilians for promotion of health. OBJECTIVE: The objective of this evidence-based review was to examine whether supplementation with l-arginine, in combination with caffeine and/or creatine, is safe and whether it enhances athletic performance or improves recovery from exhaustion for military personnel. DATA SOURCES: Information from clinical trials and adverse event reports were collected from 17 databases and 5 adverse event report portals. STUDY SELECTION: Studies and reports were included if they evaluated the safety and the putative outcomes of enhanced performance or improved recovery from exhaustion associated with the intake of arginine alone or in combination with caffeine and/or creatine in healthy adults aged 19 to 50 years. DATA EXTRACTION: Information related to population, intervention, comparator, and outcomes was abstracted. Of the 2687 articles screened, 62 articles meeting the inclusion criteria were analyzed. Strength of evidence was assessed in terms of risk of bias, consistency, directness, and precision. RESULTS: Most studies had few participants and suggested risk of bias that could negatively affect the results. l-Arginine supplementation provided little enhancement of athletic performance or improvements in recovery. Short-term supplementation with arginine may result in adverse gastrointestinal and cardiovascular effects. No information about the effects of arginine on the performance of military personnel was available. CONCLUSIONS: The available information does not support the use of l-arginine, either alone or in combination with caffeine, creatine, or both, to enhance athletic performance or improve recovery from exhaustion. Given the information gaps, an evidence-based review to assess the safety or effectiveness of multi-ingredient dietary supplements was not feasible, and therefore the development of a computational model-based approach to predict the safety of multi-ingredient dietary supplements is recommended.
Subject(s)
Arginine/administration & dosage , Arginine/adverse effects , Athletic Performance , Dietary Supplements , Military Personnel , Caffeine/administration & dosage , Cardiovascular Diseases/chemically induced , Creatine/administration & dosage , Dietary Supplements/adverse effects , Gastrointestinal Diseases/chemically induced , HumansABSTRACT
Cinnamon (Cinnamomum sp) has been suggested to help patients with type 2 diabetes mellitus (T2DM) achieve better glycemic control, although conclusions from meta-analyses are mixed. To evaluate whether the use of cinnamon dietary supplements by adults with T2DM had clinically meaningful effects on glycemic control, as measured by changes in fasting plasma glucose (FPG) or hemoglobin A1c (HbA1c), a comprehensive PubMed literature search was performed. Eleven randomized controlled trials were identified that met our inclusion criteria that enrolled 694 adults with T2DM receiving hypoglycemic medications or not. In 10 of the studies, participants continued to take their hypoglycemic medications during the cinnamon intervention period. Studies ranged from 4 to 16 weeks in duration; seven studies were double-blind. Cinnamon doses ranged from 120 to 6,000 mg/day. The species of cinnamon used varied: seven used Cinnamomum cassia or Cinnamomum aromaticum, one used Cinnamomum zeylanicum, and three did not disclose the species. Because of the heterogeneity of the studies, a meta-analysis was not conducted. All 11 of the studies reported some reductions in FPG during the cinnamon intervention, and of the studies measuring HbA1c very modest decreases were also apparent with cinnamon, whereas changes in the placebo groups were minimal. However, only four studies achieved the American Diabetes Association treatment goals (FPG <7.2 mmol/L [130 mg/dL] and/or HbAlc <7.0). We conclude that cinnamon supplements added to standard hypoglycemic medications and other lifestyle therapies had modest effects on FPG and HbA1c. Until larger and more rigorous studies are available, registered dietitian nutritionists and other health care professionals should recommend that patients continue to follow existing recommendations of authoritative bodies for diet, lifestyle changes, and hypoglycemic drugs.
Subject(s)
Cinnamomum zeylanicum , Diabetes Mellitus, Type 2/drug therapy , Dietary Supplements , Phytotherapy , Plant Extracts/pharmacology , Blood Glucose/drug effects , Diabetes Mellitus, Type 2/blood , Glycated Hemoglobin/drug effects , Humans , Hypoglycemic Agents/therapeutic use , Randomized Controlled Trials as TopicABSTRACT
Some adults with type 2 diabetes mellitus (T2DM) believe that chromium-containing supplements will help control their disease, but the evidence is mixed. This narrative review examines the efficacy of chromium supplements for improving glycemic control as measured by decreases in fasting plasma glucose (FPG) or hemoglobin A1c (HbA1c). Using systematic search criteria, 20 randomized controlled trials of chromium supplementation in T2DM patients were identified. Clinically meaningful treatment goals were defined as an FPG of ≤7.2 mmol/dL, a decline in HbA1c to ≤7%, or a decrease of ≥0.5% in HbA1c. In only a few randomized controlled trials did FPG (5 of 20), HbA1c (3 of 14), or both (1 of 14) reach the treatment goals with chromium supplementation. HbA1c declined by ≥0.5% in 5 of 14 studies. On the basis of the low strength of existing evidence, chromium supplements have limited effectiveness, and there is little rationale to recommend their use for glycemic control in patients with existing T2DM. Future meta-analyses should include only high-quality studies with similar forms of chromium and comparable inclusion/exclusion criteria to provide scientifically sound recommendations for clinicians.
Subject(s)
Blood Glucose/analysis , Chromium/administration & dosage , Diabetes Mellitus, Type 2/blood , Dietary Supplements , Fasting , Glycated Hemoglobin/analysis , Humans , Randomized Controlled Trials as TopicABSTRACT
BACKGROUND: Accurate determination of Mg status is important for improving nutritional assessment and clinical risk stratification. OBJECTIVE: We aimed to quantify the overall responsiveness of Mg biomarkers to oral Mg supplementation among adults without severe diseases and their dose- and time responses using available data from randomized controlled trials (RCTs). METHODS: We identified 48 Mg supplementation trials (n = 2131) through searches of MEDLINE and the Cochrane Library up to November 2014. Random-effects meta-analysis was used to estimate weighted mean differences of biomarker concentrations between intervention and placebo groups. Restricted cubic splines were used to determine the dose- and time responses of Mg biomarkers to supplementation. RESULTS: Among the 35 biomarkers assessed, serum, plasma, and urine Mg were most commonly measured. Elemental Mg supplementation doses ranged from 197 to 994 mg/d. Trials ranged from 3 wk to 5 y (median: 12 wk). Mg supplementation significantly elevated circulating Mg by 0.04 mmol/L (95% CI: 0.02, 0.06) and 24-h urine Mg excretion by 1.52 mmol/24 h (95% CI: 1.20, 1.83) as compared to placebo. Circulating Mg concentrations and 24-h urine Mg excretion responded to Mg supplementation in a dose- and time-dependent manner, gradually reaching a steady state at doses of 300 mg/d and 400 mg/d, or after ~20 wk and 40 wk, respectively (all P-nonlinearity ≤ 0.001). The higher the circulating Mg concentration at baseline, the lower the responsiveness of circulating Mg to supplementation, and the higher the urinary excretion (all P-linearity < 0.05). In addition, RBC Mg, fecal Mg, and urine calcium were significantly more elevated by Mg supplementation than by placebo (all P-values < 0.05), but there is insufficient evidence to determine their responses to increasing Mg doses. CONCLUSIONS: This meta-analysis of RCTs demonstrated significant dose- and time responses of circulating Mg concentration and 24-h urine Mg excretion to oral Mg supplementation.
Subject(s)
Dietary Supplements , Magnesium/administration & dosage , Magnesium/blood , Magnesium/urine , Administration, Oral , Biomarkers/blood , Dose-Response Relationship, Drug , Humans , Nutrition Assessment , Randomized Controlled Trials as Topic , Time FactorsABSTRACT
The 2015 Dietary Guidelines Advisory Committee indicated that magnesium was a shortfall nutrient that was underconsumed relative to the Estimated Average Requirement (EAR) for many Americans. Approximately 50% of Americans consume less than the EAR for magnesium, and some age groups consume substantially less. A growing body of literature from animal, epidemiologic, and clinical studies has demonstrated a varied pathologic role for magnesium deficiency that includes electrolyte, neurologic, musculoskeletal, and inflammatory disorders; osteoporosis; hypertension; cardiovascular diseases; metabolic syndrome; and diabetes. Studies have also demonstrated that magnesium deficiency is associated with several chronic diseases and that a reduced risk of these diseases is observed with higher magnesium intake or supplementation. Subclinical magnesium deficiency can exist despite the presentation of a normal status as defined within the current serum magnesium reference interval of 0.75-0.95 mmol/L. This reference interval was derived from data from NHANES I (1974), which was based on the distribution of serum magnesium in a normal population rather than clinical outcomes. What is needed is an evidenced-based serum magnesium reference interval that reflects optimal health and the current food environment and population. We present herein data from an array of scientific studies to support the perspective that subclinical deficiencies in magnesium exist, that they contribute to several chronic diseases, and that adopting a revised serum magnesium reference interval would improve clinical care and public health.
Subject(s)
Magnesium Deficiency/blood , Magnesium/blood , Nutrition Assessment , Nutrition Policy , Nutritional Requirements , Animals , Cardiovascular Diseases/blood , Cardiovascular Diseases/etiology , Humans , Inflammation/blood , Inflammation/etiology , Magnesium/urine , Magnesium Deficiency/complications , Metabolic Diseases/blood , Metabolic Diseases/etiology , Musculoskeletal Diseases/blood , Musculoskeletal Diseases/etiology , Nervous System Diseases/blood , Nervous System Diseases/etiology , Reference ValuesABSTRACT
A quality assessment of the primary studies reported in the literature carried out using select dietary ingredients (DI) purported to affect vascular endothelial function was conducted through a systematic PubMed search from January 2000 to August 2012. A total of seventy randomised controlled trials with defined DI (folic acid (fifteen), n-3 fatty acids (twenty), cocoa (fifteen) and isoflavones (twenty)) and standardised measures of vascular endothelial function were evaluated. Jadad scores, quality scoring parameters for DI and flow-mediated dilation (FMD) methodology used were ascertained. A total of 3959 randomised subjects, mean age 51 (se 0·21) years (range 9-79 years), were represented in the dataset. The mean Jadad scores did not differ statistically among the DI studies, with the majority of the studies being of good quality. Higher DI quality scores were achieved by studies using the botanical ingredients cocoa and isoflavones than by those using the nutrient ingredients folic acid and n-3 fatty acids. The mean DI quality scores were 4·13 (se 0·34), 5·20 (se 0·47), 6·13 (se 0·41) and 6·00 (se 0·59) for the folic acid, n-3 fatty acid, cocoa and isoflavone intervention studies, respectively (and significantly different). The mean Corretti FMD scores were 7·27 (se 0·56), 7·46 (se 0·79), 6·29 (se 0·61) and 7·11 (se 0·56) for the folic acid, n-3 fatty acid, cocoa and isoflavone intervention studies, respectively (NS). FMD studies failed to adequately describe the equipment used and more than half failed to provide an adequate description of the procedures used for vascular image acquisition and measurement. DI can be utilised for dietary intervention studies; however, the methodology should be clearly reported using the guidelines for assessment for both DI and FMD.