Body mass-normalized moderate dose of dietary nitrate intake improves endothelial function and walking capacity in patients with peripheral artery disease.

Peripheral artery disease (PAD) is characterized by the accumulation of atherosclerotic plaques in the lower extremity conduit arteries, which impairs blood flow and walking capacity. Dietary nitrate has been used to reduce blood pressure (BP) and improve walking capacity in PAD. However, a standardized dose for PAD has not been determined. Therefore, we sought to determine the effects of a body mass-normalized moderate dose of nitrate (0.11 mmol nitrate/kg) as beetroot juice on serum nitrate/nitrite, vascular function, walking capacity, and tissue oxygen utilization capacity in patients with PAD. A total of 11 patients with PAD received either nitrate supplement or placebo in a randomized crossover design. Total serum nitrate/nitrite, resting BP, brachial and popliteal artery endothelial function (flow-mediated dilation, FMD), arterial stiffness (pulse-wave velocity, PWV), augmentation index (AIx), maximal walking distance and time, claudication onset time, and skeletal muscle oxygen utilization were measured pre- and postnitrate and placebo intake. There were significant group × time interactions (P < 0.05) for serum nitrate/nitrite, FMD, BP, walking distance and time, and skeletal muscle oxygen utilization. The nitrate group showed significantly increased serum nitrate/nitrite (Δ1.32 µM), increased brachial and popliteal FMD (Δ1.3% and Δ1.7%, respectively), reduced peripheral and central systolic BP (Δ-4.7 mmHg and Δ-8.2 mmHg, respectively), increased maximal walking distance (Δ92.7 m) and time (Δ56.3 s), and reduced deoxygenated hemoglobin during walking. There were no changes in PWV, AIx, or claudication (P > 0.05). These results indicate that a body-mass normalized moderate dose of nitrate may be effective and safe for reducing BP, improving endothelial function, and improving walking capacity in patients with PAD.

A longitudinal study on morpho-genetic diversity of pathogenic Rhizoctonia solani from sugar beet and dry beans of western Nebraska.

BACKGROUND: Root and stem rot caused by Rhizoctonia solani is a serious fungal disease of sugar beet and dry bean production in Nebraska. Rhizoctonia root rot and crown rot in sugar beet and dry bean have reduced the yield significantly and has also created problems in storage. The objective of this study was to analyze morpho-genetic diversity of 38 Rhizoctonia solani isolates from sugar beet and dry bean fields in western Nebraska collected over 10 years. Morphological features and ISSR-based DNA markers were used to study the morphogenetic diversity. RESULTS: Fungal colonies were morphologically diverse in shapes, aerial hyphae formation, colony, and sclerotia color. Marker analysis using 19 polymorphic ISSR markers showed polymorphic bands ranged from 15 to 28 with molecular weight of 100 bp to 3 kb. Polymorphic loci ranged from 43.26-92.88%. Nei genetic distance within the population ranged from 0.03-0.09 and Shannon diversity index varied from 0.24-0.28. AMOVA analysis based on ΦPT values showed 87% variation within and 13% among the population with statistical significance (p < 0.05). Majority of the isolates from sugar beet showed nearby association within the population. A significant number of isolates showed similarity with isolates of both the crops suggesting their broad pathogenicity. Isolates were grouped into three different clusters in UPGMA based cluster analysis using marker information. Interestingly, there was no geographical correlation among the isolates. Principal component analysis showed randomized distribution of isolates from the same geographical origin. Identities of the isolates were confirmed by both ITS-rDNA sequences and pathogenicity tests. CONCLUSION: Identification and categorization of the pathogen will be helpful in designing integrated disease management guidelines for sugar beet and dry beans of mid western America.

Evaluating time in health care: What are we busy about?

At the end of the day, there are both economic and less tangible benefits to having predictable clinic operations in which people's medical and behavioral health needs are met. These different benefits, stemming from changes in how time is used, are relevant to a wide range of stakeholders including administrators, clinicians, and patients. In short, time is one of our most important resources in health care. Therefore, time studies have a crucial role to play in advancing the implementation of integrated care. In this editorial we describe several methods for measuring time and invite readers to consider which of these (or another method you're aware of) balances your needs for precision and feasibility of measurement. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Crossing the Line: Care of a Pediatric Patient with Intractable Seizures and Severe Neuropathic Pain in Absence of Access to Medical Marijuana.

Background: A reality of the current political and legal environment is that while marijuana and cannabis-based products remain not approved for human consumption at the federal level in the United States, several states have authorized use for constituents. While state lines represent meaningful cultural and geographical identity markers, the reality is that patients and families readily cross state lines to access medical interventions and care. Methods: We present the case of a six-year-old child with intractable seizures and severe neuropathic pain managed on medical marijuana (MM) in her home state of Colorado; where medicinal use of marijuana is authorized at the state level; traveling across state lines to access surgical care in Nebraska where MM is prohibited. Conclusion: The case report shares the communication and creativity invested in adequate symptom management for this child weaned off of MM perioperatively. The case recognizes the unique complexities of shared symptom management goals within state-specific care models.

Dedicated Bioenergy Crops and Water Erosion.

Information on the water quality impact of perennial warm-season grasses (WSGs) when grown in marginal lands as dedicated energy crops is limited. We studied how WSGs affected runoff, sediment, and nutrient losses and related near-surface soil properties to those of no-till corn ( L.) on an eroded soil in southwestern Iowa and a center pivot corner in east-central Nebraska. The experiment at the eroded soil was established in 2012, and treatments included 'Liberty' switchgrass ( L.) and no-till continuous corn. The experiment at the pivot corner was established in 2013 with 'Liberty' switchgrass, 'Shawnee' switchgrass, low-diversity grass mixture, and corn. We simulated rainfall at 63.5 ± 2.8 mm h for 1 h to portray 5-yr return periods and measured water erosion in spring 2017. Time to runoff start and runoff depth did not differ between WSGs and corn. On the eroded soil, sediment and nutrient losses did not differ between treatments. At the pivot corner, sediment (0.71 vs. 0.15 Mg ha) and PO-P (0.037 vs. 0.006 kg ha) losses were five times higher in corn than in WSGs. Near-surface soil properties did not differ on the eroded soil, but at the pivot corner, wet aggregate stability was four times higher and residue cover was 34% higher in WSGs than in corn. Water-stable aggregates were negatively correlated with NO-N and PO-P losses. Overall, WSGs can improve water quality in marginally productive croplands, but their effectiveness appears to be site specific.

An Academic and Practice Partnership to Assess the Behavioral Health Needs of Nebraska.

Schools of Public Health have a commitment to engage in practice-based research and be involved in collaborative partnerships. In 2016 the faculty, staff, and students from the University of Nebraska Medical Center College of Public Health and the Nebraska Department of Health and Human Services, Division of Behavioral Health collaborated to develop and administer a comprehensive assessment of the mental health and substance use disorder services provided by the Division of Behavioral Health. The purpose of this paper is to describe the process used to develop the trusting and mutually beneficial partnership and the data tools that were created and used to assess and determine the behavioral health needs. It is unrealistic to think that practitioners could undertake a project of this magnitude on their own. It is essential to have identified processes and systems in place for others to follow.

First U-Pb zircon ages for late Miocene Ashfall Konservat-Lagerstätte and Grove Lake ashes from eastern Great Plains, USA.

This paper documents the first U-Pb zircon ages for Ashfall Fossil Beds (Nebraska, USA), a terrestrial Konservat-Lagerstätte mass-death assemblage that is arguably the most diverse of its type and age. The Ashfall tephra was correlated with ignimbrites from the Bruneau-Jarbidge volcanic field (12.7-10.5 Ma) in southwest Idaho based on geochemical analysis. The methods and geochemical data supporting the original age assessment of the ash bed, however, were never published, and there has been a persistent misconception that dateable heavy minerals (e.g., zircon) are absent. Notwithstanding, we recovered abundant zircons from Ashfall Fossil Beds, and from an ash bed ~6 km to the southeast at Grove Lake, Nebraska, and analyzed them through LA-ICP-MS. Our new zircon U-Pb age of 11.86 ± 0.13 Ma substantiates correlation of the Ashfall Fossil Beds deposit to tuffs originating from the Bruneau-Jarbidge caldera (~12.7-10.5 Ma). Our U-Pb zircon age of 6.42 ± 0.06 Ma for the Grove Lake ash bed coincides with supervolcanic activity in the Heise volcanic field (6.6-4.3 Ma) in eastern Idaho. These new dates improve age constraints of strata comprising the Ogallala Group and the important paleontological site. Moreover, we find that detrital and airfall zircons are unevenly distributed in the stratified ash beds we describe herein and presumably in similar deposits worldwide. Therefore, a higher-resolution sampling scheme is necessary in such cases.

A Comparison of Vitamin E Status and Associated Pregnancy Outcomes in Maternal⁻Infant Dyads between a Nigerian and a United States Population.

Oxidative stress is associated with adverse pregnancy outcomes, and vitamin E has powerful anti-oxidant properties with the potential to impact health outcomes. Tocopherol isomers of vitamin E differ in their ability to modulate inflammation and vary in concentration in diets containing high proportions of processed versus unprocessed foods. The purpose of this study was to compare vitamin E status and associated pregnancy outcomes (mode of delivery, chorioamnionitis, APGARs (measure of appearance, pulse, grimace, activity, respiration), gestational age at delivery, and fetal growth) between maternal⁻infant dyads in a developed and a developing nation to identify potentially modifiable differences that may impact pregnancy and neonatal outcomes and provide a way to improve maternal and neonatal health. Plasma tocopherol levels were evaluated in 189 Midwestern United States (US) mother⁻infant pairs and 99 Central Nigerian mother⁻infant pairs. Maternal and infant concentrations of α-, γ-, and δ-tocopherol were measured using HPLC with diode-array detection. Descriptive statistics were calculated and tocopherol concentrations were associated with clinical outcomes such as mode of delivery, chorioamnionitis, APGARS, and fetal growth. Alpha- and γ-tocopherol levels were higher in the US mothers, (alpha: 12,357.9 (175.23⁻34,687.75) vs. 8333.1 (1576.59⁻16,248.40) (mcg/L); p < 0.001) (gamma: 340.7 (224.59⁻4385.95) vs. 357.5 (66.36⁻1775.31) (mcg/L); p < 0.001), while δ-tocopherol levels were higher in the Nigerian mothers (delta: 261.7 (24.70⁻1324.71) vs. 368.9 (43.06⁻1886.47) (mcg/L); p < 0.001). US infants had higher γ-tocopherol levels than Nigerian infants (203.1 (42.53⁻1953.23) vs. 113.8 (0.00⁻823.00) (mcg/L); p < 0.001), while both the Nigerian mothers and infants had higher α:γ-tocopherol ratios (8.5 vs. 26.2, and 8.9 vs. 18.8, respectively; p < 0.001). Our results in both populations show associations between increased circulating γ-tocopherol and negative outcomes like Caesarian sections, in contrast to the associations with positive outcomes such as vaginal delivery seen with increased α:γ-tocopherol ratios. Growth was positively associated with α- and γ-tocopherols in cord blood in the US population, and with cord blood δ-tocopherols in the Nigerian population. Tocopherol levels likely impact health outcomes in pregnancy in a complicated metabolism across the maternal⁻fetal axis that appears to be potentially influenced by culture and available diet.

A Survey of Dental Patient Attitudes on the Likelihood and Perceived Importance of Disclosing Daily Medications.

An accurate medication history allows the oral health care provider (OHCP) to evaluate a patient's overall health and disease status, as well as assess the effect medications may have on dental treatment and oral health. It has been previously documented that dental patients do not always report an accurate medication list. The aims of this study were to determine dental patients' perceptions regarding the importance and likelihood of accurately disclosing prescription, over-the-counter (OTC), and herbal/supplement medications to their OHCP. A voluntary patient survey was administered from October 2015 through March 2016 to new dental patients at the Creighton University School of Dentistry student-operated clinic. Of 300 surveys distributed, 217 were found to be complete for inclusion in the evaluation (response rate 72.3%). Of the responding patients, 75.6%, 69.1%, and 63.6% reported believing it was very important to inform their dentists of their prescribed, OTC, and herbal/supplement medications, respectively. Additionally, 80.7%, 71.4%, and 62.7% reported that they always informed their dentists of all their prescribed, OTC, and herbal/supplement medications, respectively. Although the majority of these patients agreed on the importance of reporting medication information to their OHCP and reported doing so, this survey found room for improvement, especially regarding OTC and herbal/supplement medications. It is imperative that both the pharmacist and OHCP educate dental and pharmacy students to inform patients of the importance of providing an accurate and complete medication history to ensure the safest possible delivery of their dental treatment.

Effect of Vitamin D and Calcium Supplementation on Cancer Incidence in Older Women: A Randomized Clinical Trial.

Importance: Evidence suggests that low vitamin D status may increase the risk of cancer. Objective: To determine if dietary supplementation with vitamin D3 and calcium reduces the risk of cancer among older women. Design, Setting, and Participants: A 4-year, double-blind, placebo-controlled, population-based randomized clinical trial in 31 rural counties (June 24, 2009, to August 26, 2015-the final date of follow-up). A total of 2303 healthy postmenopausal women 55 years or older were randomized, 1156 to the treatment group and 1147 to the placebo group. Duration of treatment was 4 years. Interventions: The treatment group (vitamin D3 + calcium group) received 2000 IU/d of vitamin D3 and 1500 mg/d of calcium; the placebo group received identical placebos. Main Outcomes and Measures: The primary outcome was the incidence of all-type cancer (excluding nonmelanoma skin cancers), which was evaluated using Kaplan-Meier survival analysis and proportional hazards modeling. Results: Among 2303 randomized women (mean age, 65.2 years [SD, 7.0]; mean baseline serum 25-hydroxyvitamin D level, 32.8 ng/mL [SD, 10.5]), 2064 (90%) completed the study. At year 1, serum 25-hydroxyvitamin D levels were 43.9 ng/mL in the vitamin D3 + calcium group and 31.6 ng/mL in the placebo group. A new diagnosis of cancer was confirmed in 109 participants, 45 (3.89%) in the vitamin D3 + calcium group and 64 (5.58%) in the placebo group (difference, 1.69% [95% CI, -0.06% to 3.46%]; P = .06). Kaplan-Meier incidence over 4 years was 0.042 (95% CI, 0.032 to 0.056) in the vitamin D3 + calcium group and 0.060 (95% CI, 0.048 to 0.076) in the placebo group; P = .06. In unadjusted Cox proportional hazards regression, the hazard ratio was 0.70 (95% CI, 0.47 to 1.02). Adverse events potentially related to the study included renal calculi (16 participants in the vitamin D3 + calcium group and 10 in the placebo group), and elevated serum calcium levels (6 in the vitamin D3 + calcium group and 2 in the placebo group). Conclusions and Relevance: Among healthy postmenopausal older women with a mean baseline serum 25-hydroxyvitamin D level of 32.8 ng/mL, supplementation with vitamin D3 and calcium compared with placebo did not result in a significantly lower risk of all-type cancer at 4 years. Further research is necessary to assess the possible role of vitamin D in cancer prevention. Trial Registration: clinicaltrials.gov Identifier: NCT01052051.

Promoting colorectal cancer screening through a new model of delivering rural primary care in the USA: a qualitative study.

INTRODUCTION: Despite the known benefits of colorectal cancer (CRC) screening, rural areas have consistently reported lower screening rates than their urban counterparts. Alternative healthcare delivery models, such as accountable care organizations (ACOs), have the potential to increase CRC rates through collaboration among healthcare providers with the aim of improving quality and decreasing cost. However, researchers have not sufficiently explored how this innovative model could influence the promotion of cancer screening. The purpose of the study was to explore the mechanism of how CRC screening can be promoted in ACO-participating rural primary care clinics. METHODS: The study collected qualitative data from in-depth interviews with 21 healthcare professionals employed in ACO-participating primary care clinics in rural Nebraska. Participants were asked about their views on opportunities and challenges to promote CRC screening in an ACO context. Data were analyzed using a grounded theory approach. RESULTS: The study found that the new healthcare delivery model can offer opportunities to promote cancer screening in rural areas through enhanced electronic health record use, information sharing and collaborative learning within ACO networks, use of standardized quality measures and performance feedback, a shift to preventive/comprehensive care, adoption of team-based care, and empowered care coordinators. The perceived challenges were found in financial instability, increased staff workload, lack of provider training/education, and lack of resources in rural areas. CONCLUSIONS: This study found that the innovative care delivery model, ACO, could provide a well-designed platform for promoting CRC screening in rural areas, if sustainable resources (eg finance, health providers, and education) are provided. This study provides 'practical' information to identify effective and sustainable intervention programs to promote preventive screening. Further efforts are needed to facilitate delivery system reforms in rural primary care, such as improving performance evaluation measures and methods.

Behavioral Health Problems Presented to Integrated Pediatric Behavioral Health Clinics: Differences in Urban and Rural Patients.

Behavioral health diagnoses and service use may differ based on rurality. The purpose of this study was to examine the patterns of mental disorder diagnoses of urban, rural, and remote pediatric populations. This retrospective study used electronic medical records from integrated behavioral health clinics in Nebraska from 2012 to 2013. Bivariate and multivariable models were used to examine the differences in diagnoses. Adolescents with attention deficit and related disorders were more likely to be male, younger, have public insurance and rural/remote residents. Adjustment disorders were associated with being female, older, and urban residents. Adolescents with anxiety disorder had a significant interaction between age and gender, with both genders being older, having private insurance, and urban residents. Adolescents with mood disorder were more likely to be female, older, and urban residents. Demographic and clinical differences among patients in urban and rural/remote settings have implications for care in rural settings.

Response of Pemphigus betae (Hemiptera: Aphididae) and Beneficial Epigeal Arthropod Communities to Sugarbeet Plant Density and Seed-Applied Insecticide in Western Nebraska.

This study investigated the impact of a neonicotinoid seed-applied insecticide (Poncho Beta) and two plant densities (86,487 and 61,776 plants per hectare) on the sugarbeet root aphid (Pemphigus betae Doane), beneficial epigeal arthropods, and selected crop yield parameters in sugarbeet (Beta vulgaris L. var. vulgaris). Ground beetles and centipedes were the most commonly collected taxa during 2012 and 2013, respectively. Centipede, spider, and rove beetle activity densities were not affected by the seed-applied insecticide, whereas plant density had a marginal effect on centipede activity density during 2012. Ground beetle species richness, diversity, and evenness were also not impacted by the seed treatments. However, during 2013, ground beetle activity density was significantly higher in plots planted with untreated sugarbeet seeds due to the abundance of Bembidion quadrimaculatum oppositum Say. Sugarbeet root aphid populations were significantly higher in the untreated plots during both years. In 2012, sugarbeet tonnage and sugar yield were higher under the low plant density treatment, while higher sugar content was recorded from the seed-applied insecticide plots (2013). Seed-applied neonicotinoids and plant density had little impact on beneficial epigeal arthropod activity density. Seed treatment did result in decreased root aphid populations; however, these reductions were not sufficient to be considered as an adequate control. This limited aphid control likely contributed to inconsistent effects on yield parameters.

A Comparison of the J-1 Visa Waiver and Loan Repayment Programs in the Recruitment and Retention of Physicians in Rural Nebraska.

PURPOSE: There is a dearth of literature evaluating the effectiveness of programs aimed at recruiting and retaining physicians in rural Nebraska. Taking advantage of the Nebraska Health Professional Tracking System, this study attempts to comparatively assess the effectiveness of the J-1 visa waiver and state loan repayment programs in the recruitment and retention of physicians in rural Nebraska. METHODS: A mixed methods approach was used. We tracked 240 physicians who enrolled in the J-1 visa waiver and state loan repayment programs between 1996 and 2012 until 2013. In addition, key informant interviews were conducted to obtain perspectives on the recruitment and retention of physicians in rural Nebraska through the 2 programs. FINDINGS: Results from multilevel survival regression analysis indicated that physicians enrolled in the J-1 visa waiver program were more likely to leave rural Nebraska when compared with those enrolled in the state loan repayment program. Participants in the qualitative study, however, cautioned against declaring one program as superior over the other, given that the 2 programs addressed different needs for different communities. In addition, results suggested that fostering the integration of physicians and their families into rural communities might be a way of enhancing retention, regardless of program. CONCLUSION: The findings from this study highlight the complexity of recruitment and retention issues in rural Nebraska and suggest the need for more holistic and family-centered approaches to addressing these issues.

Visualization of Atrioventricular Nodal Reentry Tachycardia Slow Pathways Using Voltage Mapping for Pediatric Catheter Ablation.

BACKGROUND: Catheter ablation of the slow atrioventricular (AV) pathway has been shown to be safe and effective in pediatric patients with atrioventricular nodal reentrant tachycardia (AVNRT). Despite that, acute success is not guaranteed, and safety of ablating near the AV node remains a concern. METHODS: A retrospective analysis was performed of all AVNRT ablations using the Ensite NavX voltage mapping technique at our institution. Each map was reviewed with patient and NavX computer data recorded. To account for a learning curve, each map was idealized and compared with the original map. Procedure and fluoroscopy time were compared with a control group. RESULTS: Twenty-eight patients underwent catheter ablation for AVNRT from September 2011 until December 2012 using the voltage mapping technique. The historical control group comprised 24 patients who underwent catheter ablation using the electroanatomic approach. There was 96% acute success with one recurrence in the voltage mapping group, at a mean follow-up of 24 months. The slow pathway was visualized in 86% of patients at the time of ablation, while three of four without could be found on idealization of the voltage map. Mean high- and low-voltage parameters increased with idealization, but showed no correlation with age, gender, or weight. Estimated pathway size had significant inter-patient variability. Procedure and fluoroscopy times did not vary significantly compared with controls. CONCLUSION: Visualization of the AV nodal slow pathway in a pediatric population is possible using voltage mapping technique with the potential to increase safety and efficacy. Variability exists in the voltage parameters needed to visualize individual slow pathways, which leads to a distinct learning curve.

The influence of cognitive decline on rural identity: perspectives of older women.

PURPOSE: The purpose of this study was to examine the perspectives of community-dwelling rural, older women concerning the meaning of cognitive decline and to ascertain how cognitive decline affects their lives and the lives of those around them. DESIGN: An ethnographic design guided 1 year of cultural immersion in a rural, farming county in Nebraska. METHOD: Four life history interviews, participant observations, field notes, and cultural artifacts were collected for case-focused analysis. FINDINGS: Cognitive decline was believed to threaten one's social identity as a "good woman" because of three strongly held beliefs that (1) the rural lifestyle protected health, (2) demands of the farm were more important than personal health needs, and (3) mainstream health care services were unnatural and insensitive, and therefore best avoided. Using mainstream health care also resulted in the loss of informal social support, which existed as a protective social silence and helped sustain older women's rural identity. The older women feared developing cognitive decline and believed the loss of one's life purpose would be the outcome of the condition. CONCLUSIONS: Holistic nursing actions that preserve older women's rural identity and social support may increase the likelihood that women accept rural health care aimed at treating cognitive decline.

Tobacco Use and Its Relationship to Social Determinants of Health in LGBT Populations of a Midwestern State.

PURPOSE: Researchers have documented that lesbian, gay, bisexual, and transgender (LGBT) people have a higher proportion of tobacco use as compared to general population smoking rates. This study examined the relationships between tobacco use and social determinants of health in a sample of self-identifying LGBT people who spend time in Nebraska. METHODS: A community-based participatory research approach was used to develop an online survey to assess the physical, mental, social, and sexual health of LGBT populations who live, work, or play in Nebraska. Chi-squared and logistic regression analyses explored the use of tobacco among respondents. RESULTS: Of the 770 people who completed the survey, 763 respondents completed questions about smoking status. The prevalence of current smoking among these 763 respondents was 26.47%. Some LGBT-specific social determinants of health had significant relationships to smoking status. However, after controlling for known risk factors of smoking in logistic regression models, these variables were not related to smoking status. CONCLUSIONS: This study shows that there is a significant relationship between smoking and several general social determinants of health, including employment status, education, and income as well as binge drinking. Limitations include lack of adequate survey respondents to divide subgroups of LGBT individuals and inherent limitations of convenience sampling, which may not allow for an accurate representation of the situation faced by LGBT in Nebraska. In addition to this, the list of LGBT-specific determinants of health used in the survey may not be exhaustive, and there may be additional factors facing LGBT individuals. Public health professionals can use this information in designing smoking reduction campaigns for LGBT populations in Nebraska and culturally similar regions of the United States. These programs and interventions may want to consider a more holistic approach to smoking cessation grounded in the social-ecological model.

25-Hydroxyvitamin D response to graded vitamin D3 supplementation among obese adults.

CONTEXT: Guidelines have suggested that obese adults need 2 to 3 times more vitamin D than lean adults to treat vitamin D deficiency, but few studies have evaluated the vitamin D dose response in obese subjects. OBJECTIVE: The purpose of this study was to characterize the pharmacokinetics of 25-hydroxyvitamin D [25(OH)D] response to 3 different doses of vitamin D3 (cholecalciferol) in a group of obese subjects and to quantify the 25(OH)D dose-response relationship. DESIGN, SETTING, INTERVENTION, PATIENTS: This was a randomized, single-blind study of 3 doses of oral vitamin D3 (1000, 5000, or 10,000 IU) given daily to 67 obese subjects for 21 weeks during the winter months. MAIN OUTCOME MEASURES: Serum 25(OH)D levels were measured at baseline and after vitamin D replacement, and 25(OH)D pharmacokinetic parameters were determined, fitting the 25(OH)D concentrations to an exponential model. RESULTS: Mean measured increments in 25(OH)D at week 21 were 12.4 ± 9.7 ng/mL in the 1000 IU/d group, 27.8 ± 10.2 ng/mL in the 5000 IU/d group, and 48.1 ± 19.6 ng/mL in the 10,000 IU/d group. Steady-state increments computed from the model were 20.6 ± 17.1, 35.2 ± 14.6, and 51.3 ± 22.0 ng/mL, respectively. There were no hypercalcuria or hypercalcemia events during the study. CONCLUSION: Our data show that in obese people, the 25(OH)D response to vitamin D3 is directly related to dose and body size with ∼2.5 IU/kg required for every unit increment in 25(OH)D (nanograms per milliliter).

Calcium absorption response to cholecalciferol supplementation in hemodialysis.

BACKGROUND AND OBJECTIVES: Recent understanding of extrarenal production of calcitriol has led to the use of more vitamin D supplementation in CKD populations. This paper reports the effect of cholecalciferol supplementation on calcium absorption. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Paired calcium absorption tests were done before and after 12-13 weeks of 20,000 IU weekly cholecalciferol supplementation in 30 participants with stage 5 CKD on hemodialysis. The study was conducted from April to December of 2011. Calcium absorption was tested with a standardized meal containing 300 mg calcium carbonate intrinsically labeled with (45)Ca; 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D were measured. RESULTS: 25-Hydroxyvitamin D rose from 14.2 ng/ml (11.5-18.5) at baseline to 49.3 ng/ml (42.3-58.1) at the end of the study (P<0.001). 1,25-Dihydroxyvitamin D rose from 15.1 (10.5-18.8) pg/ml at baseline to 20.5 (17.0-24.7) pg/ml at the end of the study (P<0.001). The median baseline calcium absorption was 12% (7%-17%) and 12% (7%-16%) at the end of study. CONCLUSIONS: Patients with stage 5 CKD on hemodialysis had very low calcium absorption values at baseline, and cholecalciferol supplementation that raised 25(OH)D levels to 50 ng/ml had no effect on calcium absorption.