Monitoring the utilization and effectiveness of Iron and Vitamin D supplementations program and its predictive factors in high schools' girls in Qom, Iran.

Background: Iron and Vitamin D3 deficiency is one of the major global health problems in teenagers and adolescent population. This study was aimed to monitor the utilization and predictive factors of Iron and Vitamin D Supplementations Program (IVDSP) in high schools' girls. Methods: In a cross sectional study, the pattern of Iron and D3 consumption based on IVDSP on 400 high schools' girl in Qom, Iran assesses. Data collection was used by a reliable and standard researcher based questionnaire and daily, weekly, monthly and seasonally consumption of complementary minerals in schools were gathered. Data analysis conducted using SPSS version 20 (SPSS Inc., Chicago, IL, USA) by chi square, independent t-test and multivariate logistic regression. Results: The mean age of subjects was 15.14 ± 1.52 years and ranged from 12 to 18 years old. The total weekly prevalence of D3 and Iron consumption in high schools' girls was calculated 36.73% and the weekly prevalence of Iron and monthly prevalence of Vitamin D3 consumption was 33.75% and 40.5%, respectively. The most common causes of non-consumption were bad taste 49.31%, Iranian made drug 20.27%, drug sensitivity 19.82% and drug interaction 10.60%, respectively. Conclusions: The inadequate and incomplete rate of IVDSP in Qom was high and more than 60% of distributed supplementations have been wasted. Results showed that students who were participated in educational orientation classes were more successful and eager in Iron and Vitamin D3 consumption. Therefore, more educational explanatory interventions for both students and her parents recommended to increase the efficiency of the program.

Effect of vitamin D, calcium, or combined supplementation on fall prevention: a systematic review and updated network meta-analysis.

BACKGROUND: The association between vitamin D supplementation and the risk of falls in older adults has been controversial. This systematic review and network meta-analysis aims to assess the efficacy of vitamin D, calcium, and combined supplementation in the prevention of falls. METHODS: Randomized controlled trials (RCTs) on the efficacy of vitamin D in fall prevention were systematically searched in PubMed, Embase, Cochrane Library, and Web of Science from inception to May 9, 2023. The network meta-analysis was performed using a random effects model in R4.1.3 and Stata15.0. Heterogeneity was evaluated by the I2 statistic, and publication bias was assessed using funnel plots, Begg's test, and Egger's tests. Data were pooled and expressed as relative risk (RR) and 95% confidence interval (CI). RESULTS: A total of 35 RCTs involving 58,937 participants were included in this study, among which 11 RCTs (31.4%) applied calcium combined with vitamin D. There was low heterogeneity (I2 = 11%) among the included studies. Vitamin D supplementation at 800-1000 International Unit (IU)/d resulted in a lower risk of falls than placebo or no treatment (RR = 0.85, 95%CI: 0.74-0.95). In addition, 800-1000 IU/d of vitamin D with or without calcium were more effective in preventing falls than calcium alone. High-dose vitamin D (> 1000 IU/day) increased the risk of falls compared with 800-1000 IU/d of vitamin D. According to the subgroup analysis, daily administration of 800-1000 IU/d vitamin D was associated with a 22% reduction in the risk of falls (RR = 0.78, 95%CI:0.64-0.92), whereas intermittent vitamin D administration had no preventive effect. Furthermore, 800-1000 IU/d of vitamin D also significantly decreased the risk of falls in old adults with ≤ 50 nmol/L 25-hydroxyvitamin D [25(OH)D] (RR = 0.69, 95%CI:0.52-0.86) but not in individuals with > 50 nmol/L 25(OH)D. CONCLUSION: Vitamin D supplementation at 800-1000 IU/d is associated with a lower risk of falls among older adults. 800-1000IU/d of vitamin D has a benefit on prevention of falls in population received daily dose regimens and in population with vitamin D deficiency.

The Efficacy of Multivitamin, Vitamin A, Vitamin B, Vitamin C, and Vitamin D Supplements in the Prevention and Management of COVID-19 and Long-COVID: An Updated Systematic Review and Meta-Analysis of Randomized Clinical Trials.

This review aims to evaluate the efficacy of any vitamin administration(s) in preventing and managing COVID-19 and/or long-COVID. Databases were searched up to May 2023 to identify randomized clinical trials comparing data on the effects of vitamin supplementation(s) versus placebo or standard of care on the two conditions of interest. Inverse-variance random-effects meta-analyses were conducted to estimate pooled risk ratios (RRs) and 95% confidence intervals (CIs) for all-cause mortality between supplemented and non-supplemented individuals. Overall, 37 articles were included: two regarded COVID-19 and long-COVID prevention and 35 records the COVID-19 management. The effects of vitamin D in preventing COVID-19 and long-COVID were contrasting. Similarly, no conclusion could be drawn on the efficacy of multivitamins, vitamin A, and vitamin B in COVID-19 management. A few positive findings were reported in some vitamin C trials but results were inconsistent in most outcomes, excluding all-cause mortality (RR = 0.84; 95% CI: 0.72-0.97). Vitamin D results were mixed in most aspects, including mortality, in which benefits were observed in regular administrations only (RR = 0.67; 95% CI: 0.49-0.91). Despite some benefits, results were mostly contradictory. Variety in recruitment and treatment protocols might explain this heterogeneity. Better-designed studies are needed to clarify these vitamins' potential effects against SARS-CoV-2.

Vitamins in Gynecologic Malignancies.

The combination of vitamin A and D derivatives with classical chemotherapeutic treatments results in more satisfactory outcomes. The use of drug combinations, such as 9cUAB130 with carboplatin and cisplatin with TAC-101, shows enhanced cytotoxic effects and reductions in ovarian tumor volume compared to single-drug treatments. Combining cisplatin with calcitriol and progesterone increases VDR expression, potentially enhancing the effectiveness of anticancer therapy in ovarian cancer. The effectiveness of vitamin derivatives in anticancer treatment may vary depending on the characteristics of the tumor and the cell line from which it originated. An increase in thiamine intake of one unit is associated with an 18% decrease in HPV infection. Higher intake of vitamin C by 50 mg/day is linked to a lower risk of cervical neoplasia. Beta-carotene, vitamin C, and vitamin E are associated with risk reductions of 12%, 15%, and 9% in endometrial cancer, respectively. A balanced daily intake of vitamins is important, as both deficiency and excess can influence cancer development. It has been observed that there is a U-shaped relationship between group B vitamins and metabolic markers and clinical outcomes.

Diet and omega-3 and vitamin D supplement use predict five-year fatigue and disability trajectories in people with multiple sclerosis.

BACKGROUND: Fatigue and disability are indicators of disease progression experienced by many people with multiple sclerosis (pwMS). Understanding trajectories of these outcomes, and their predictors, may provide insight to potential interventions for MS management. METHODS: Survey data from 839 pwMS from the Health Outcomes and Lifestyle in pwMS study were analysed. Fatigue was defined as mean Fatigue Severity Scale >5, and severe disability as Patient Determined Disease Steps >5. Group-based trajectory modelling was used to identify fatigue and disability trajectories over five-years. Dietary predictors associated with outcome trajectory group membership were assessed using log-binomial regression. Demographic and clinical characteristics were considered in multivariable models. RESULTS: Distinct trajectories for fatigue and disability were identified. For fatigue, 58 % of pwMS were assigned to low-, and 42 % to high-, fatigue trajectory groups. For disability, 85 % of pwMS were assigned to low-, and 15 % to high-, disability groups. Baseline high-quality diet, and omega-3 and vitamin D supplement use, were associated with reduced risk of being in high-fatigue and high-disability trajectories, while meat and dairy consumption were associated with increased risk. CONCLUSIONS: A high-quality diet, avoiding meat and dairy, and omega-3 and vitamin D supplement use, individually predict better fatigue and disability trajectories. Dietary modifications should be considered in MS management.

Effect of vitamin D in addition to letrozole on the ovulation rate of women with polycystic ovary syndrome: protocol of a multicentre randomised double-blind controlled trial.

INTRODUCTION: Low vitamin D status is prevalent among women with polycystic ovary syndrome (PCOS). The objective of the study is to assess the effect of vitamin D supplementation on (1) the ovulation rate to letrozole and (2) other reproductive, endocrine and metabolic outcomes after 1 year of supplementation in women with PCOS. METHODS AND ANALYSIS: This is a multicentre, randomised, double-blind, controlled clinical trial. A total of 220 anovulatory women with PCOS diagnosed by the Rotterdam criteria will be recruited. They will be randomly assigned to either the (1) vitamin D supplementation group or (2) placebo group. Those in the vitamin D group will take oral Vitamin D3 50 000 IU/week for 4 weeks, followed by 50 000 IU once every 2 weeks for 52 weeks. Those who remain anovulatory after 6 months will be treated with a 6-month course of letrozole (2.5 mg to 7.5 mg for 5 days per cycle titrated according to response) for ovulation induction. The primary outcome is the ovulation rate. All statistical analyses will be performed using intention-to-treat and per protocol analyses. ETHICS AND DISSEMINATION: Ethics approval was sought from the Institutional Review Board of the participating units. All participants will provide written informed consent before joining the study. The results of the study will be submitted to scientific conferences and peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT04650880.

Enhanced Metabolic Effects of Fish Oil When Combined with Vitamin D in Diet-Induced Obese Male Mice.

Vitamin D (vit D) and fish oil (FO) both offer unique health benefits, however, their combined effects have not been evaluated in obesity and nonalcoholic fatty liver disease (NAFLD). Hence, we hypothesized that vit D and FO supplementation would have additive effects in reducing obesity-associated inflammation and NAFLD. Male C57BL6 mice were split into four groups and fed a high fat (HF) diet supplemented with a low (HF; +200 IU vit D) or high dose of vitamin D (HF + D; +1000 IU vit D); combination of vit D and FO (HF-FO; +1000 IU vit D); or only FO (HF-FO; +200 IU vit D) for 12 weeks. We measured body weight, food intake, glucose tolerance, and harvested epididymal fat pad and liver for gene expression analyses. Adiposity was reduced in groups supplemented with both FO and vit D. Glucose clearance was higher in FO-supplemented groups compared to mice fed HF. In adipose tissue, markers of fatty acid synthesis and oxidation were comparable in groups that received vit D and FO individually in comparison to HF. However, the vit D and FO group had significantly lower fatty acid synthesis and higher oxidation compared to the other groups. Vit D and FO also significantly improved fatty acid oxidation, despite similar fatty acid synthesis among the four groups in liver. Even though we did not find additive effects of vit D and FO, our data provide evidence that FO reduces markers of obesity in the presence of adequate levels of vit D.

The Power of Vitamin D: Is the Future in Precision Nutrition through Personalized Supplementation Plans?

In the last few decades, vitamin D has undeniably been one of the most studied nutrients. Despite our ability to produce vitamin D through sunlight exposure, its presence in several natural food sources and fortified foods, and its widespread availability as a dietary supplement, vitamin D deficiency is a serious public health problem, affecting nearly 50% of the global population. Low serum levels of vitamin D are being associated with increased susceptibility to numerous health conditions, including respiratory infections, mental health, autoimmune diseases, and different cancer types. Although the association between vitamin D status and health is well-established, the exact beneficial effects of vitamin D are still inconclusive and indefinite, especially when considering the prevention and treatment of different health conditions and the determination of an appropriate dosage to exert those beneficial effects in various population groups. Therefore, further research is needed. With constant improvements in our understanding of individual variations in vitamin D metabolism and requirements, in the future, precision nutrition and personalized supplementation plans could prove beneficial.

Vitamin D regulates microbiome-dependent cancer immunity.

A role for vitamin D in immune modulation and in cancer has been suggested. In this work, we report that mice with increased availability of vitamin D display greater immune-dependent resistance to transplantable cancers and augmented responses to checkpoint blockade immunotherapies. Similarly, in humans, vitamin D-induced genes correlate with improved responses to immune checkpoint inhibitor treatment as well as with immunity to cancer and increased overall survival. In mice, resistance is attributable to the activity of vitamin D on intestinal epithelial cells, which alters microbiome composition in favor of Bacteroides fragilis, which positively regulates cancer immunity. Our findings indicate a previously unappreciated connection between vitamin D, microbial commensal communities, and immune responses to cancer. Collectively, they highlight vitamin D levels as a potential determinant of cancer immunity and immunotherapy success.

Microbes and vitamin D aid immunotherapy.

Vitamin D modulates intestinal epithelial cell function to enhance antitumor microbes.

Home Meal Replacement Fortified with Eggshell Powder and Vitamin D Prevents Bone Loss in Postmenopausal Women: A Randomized, Double-Blind, Controlled Study.

Calcium and vitamin D deficiencies have been ongoing problems in Koreans due to a lack of food sources of calcium and vitamin D. Postmenopausal women aged 50 to 64 years (n = 25) were randomly assigned to consume three home meal replacements (HMRs)/week with (treatment) and without (control) eggshell powder and vitamin D for 6 months. Additionally, subjects who agreed to continue the study consumed the same three HMRs/week for an additional 6 months in this randomized double-blind study. We confirmed the high compliance of the study participants by analyzing carotenoids, the bioactive substances of HMRs, in the blood. The treatment group consumed an additional 261 mg/d of calcium and 10.3 µg/d of vitamin D from the HMRs, thus meeting the recommended intakes of calcium and vitamin D for Koreans. As a result of consuming fortified HMRs for 6 months, the decline in femoral neck bone density was significantly reduced in the treatment group (p = 0.035). This study indicates that inexpensive eggshell powder may be a good source of calcium for populations with low consumption of milk and dairy products. Additionally, functional HMRs fortified with eggshell powder and vitamin D can be a good dietary strategy for bone health.

Effect of Calcium and Vitamin D Supplementation (Dairy vs. Pharmacological) on Bone Health of Underprivileged Indian Children and Youth with Type-1 Diabetes: A Randomized Controlled Trial.

BACKGROUND: Bone health is affected by chronic childhood disorders including type-1 diabetes mellitus (T1DM). We conducted this randomized controlled trial with the objective of investigating the effect of 1-year supplementation of vitamin-D with milk or with pharmacological calcium on bone mass accrual in underprivileged Indian children and youth with T1DM. METHODS: 5 to 23year old (n = 203) underprivileged children and youth with T1DM were allocated to one of three groups: Milk (group A-received 200 ml milk + 1000 international unit (IU) vitamin-D3/day), Calcium supplement (group B-received 500 mg of calcium carbonate + 1000 IU of vitamin-D3/day) or standard of care/control (group C). Anthropometry, clinical details, biochemistry, diet (3-day 24-h recall), physical activity (questionnaires adapted for Indian children) and bone health parameters (using dual-energy X-ray absorptiometry and peripheral quantitative computed tomography- DXA and pQCT respectively) were evaluated at enrolment and end of 12 month intervention. RESULTS: Total body less head(TBLH) bone mineral content (BMC(g)) and bone mineral density (BMD(gm/cm2)) were significantly higher at end of study in girls in both supplemented groups (TBLHBMC-A-1011.8 ±â€¯307.8, B-983.2 ±â€¯352.9, C-792.8 ±â€¯346.8. TBLHBMD-A-± 0.2, B-0.8 ±â€¯0.2, C-0.6 ±â€¯0.2, p < 0.05). Z score of lumbar spine bone mineral apparent density of supplemented participants of both sexes was significantly higher than controls (Boys- A-0.7 ±â€¯1.1, B-0.6 ±â€¯1.4, C- -0.7 ±â€¯1.1; Girls- A-1.1 ±â€¯1.1, B-0.9 ±â€¯3.4, C- -1.7 ±â€¯1.3, p < 0.05). A significantly higher percentage increase was found in cortical thickness in girls in both supplemented groups (A-17.9 ±â€¯28.6, B-15.3 ±â€¯16.5, C-7.6 ±â€¯26.2); the differences remained after adjusting for confounders. CONCLUSION: Supplementation with milk or pharmacological calcium (+vitaminD3) improved bone outcomes-particularly geometry in children with T1DM with more pronounced effect in girls. Pharmacological calcium may be more cost effective in optimising bone health in T1DM in resource limited settings.

The dietary risk factors on cancer patients receiving chemotherapy and correlation between serum vitamin D and b12 levels, depression and anxiety status / Factores de riesgo dietéticos en pacientes con cáncer que reciben quimioterapia y relación entre los niveles séricos de vitamina D y B12 y la depresión y la ansiedad

Objective: the aim of this study is to evaluate the relationship between serum vitamin D and B12 levels, nutritional levels, depression, and anxiety in adult cancer patients before and after chemotherapy. Methods: a case-controlled study was carried out on 44 patients who were diagnosed with cancer and applied to the Chemotherapy Unit for treatment (patient group, PG) and 44 volunteer individuals (control group, CG) with similar characteristics to the age and gender-matched patient group but with no diagnosis of cancer. Results: the average age of individuals in PG is 52.50 ± 12.21 years and for those in CG is 52.84 ± 10.98 years. Serum D and B12 levels in the first cure in individuals in PG are higher than in the last treatment (p > 0.05). It was determined that vitamin C taken with a daily diet reduces the risk of cancer (OR: 0.920, 95 % CI: 0.899-0.942, p = 0.042). No correlation was found between depression and anxiety scores of both groups and serum vitamin D and B12 levels (p > 0.05). It was determined that the Beck Anxiety Inventory (BAI) score increased with decrease in body mass index (BMI) (β = 0.311, p = 0.040) and serum vitamin B12 level (β = -0.406, p = 0.006). In addition, it was found that the increase in the Patient-Generated Subjective Global Assessment (PG-SGA) score, which reflects the nutritional status of cancer patients, worsened the level of anxiety (β = 0.389, p = 0.009). Conclusions: as stated in the findings of the study, chemotherapy treatment mediated the development of anxiety in cancer patients by changing the vitamin B12 levels and anthropometric characteristics with its negative effect on nutritional status. It should be ensured that cancer patients treated with chemotherapy follow a healthy and balanced diet plan that is suitable for their needs and has adequate vitamin and mineral content.(AU)

Objetivo: el objetivo de este estudio es evaluar la relación entre los niveles séricos de vitamina D y B12, el estado nutricional y el estado de depresión y de ansiedad antes y después de la quimioterapia en pacientes adultos con cáncer que están recibiendo quimioterapia. Métodos: se realizó un estudio de casos controlados en 44 pacientes diagnosticados de cáncer (grupo de pacientes, GP) que solicitaron tratamiento a la Unidad de Quimioterapia y 44 voluntarios sanos (grupo de control, GC) sin diagnóstico de cáncer y que tenían características similares al grupo GP en cuanto a edad y sexo. Resultados: la edad media de los individuos del GP fue de 52,50 ± 12,21 años, mientras que la del GC fue de 52,84 ± 10,98 años. Los niveles séricos de vitamina D y B12 en individuos del GP en el primer ciclo fueron más altos que en el último ciclo (p > 0,05). Se determinó que la vitamina C tomada en la dieta diaria reduce el riesgo de cáncer (OR: 0,920, IC del 95 %: 0,899-0,942, p = 0,042). No se detectó una correlación entre las puntuaciones de depresión y ansiedad de ambos grupos y los niveles séricos de vitamina D y B12 (p > 0,05). Se determinó que la puntuación Inventario de Ansiedad de Beck (BAI) aumentó con la disminución del índice de masa corporal (IMC) (β = 0,311, p = 0,040) y el nivel sérico de vitamina B12 (β = -0,406, p = 0,006). Además, se objetivó que el aumento en la puntuación en el Patient-Generated Subjective Global Assessment (PG-SGA), que refleja el estado nutricional de los pacientes con cáncer, empeoró el nivel de ansiedad (β = 0,389, p = 0,009). Conclusión: como se indica en los hallazgos del estudio, el tratamiento con quimioterapia medió en el desarrollo de ansiedad en pacientes con cáncer al cambiar los niveles de vitamina B12 y las características antropométricas con su efecto negativo en el estado nutricional...(AU)

Effect of vitamin D supplementation or fortification on bone turnover markers in women: a systematic review and meta-analysis.

Vitamin D is a vital indicator of musculoskeletal health, as it plays an important role through the regulation of bone and mineral metabolism. This meta-analysis was performed to investigate the effects of vitamin D supplementation/fortification on bone turnover markers in women. All human randomised clinical trials reported changes in bone resorption markers (serum C-terminal telopeptide of type-I collagen (sCTX) and urinary type I collagen cross-linked N-telopeptide (uNTX)) or bone formation factors (osteocalcin (OC), bone alkaline phosphatase (BALP) and procollagen type-1 intact N-terminal propeptide (P1NP)) following vitamin D administration in women (aged ≥ 18 years) were considered. Mean differences (MD) and their respective 95 % CI were calculated based on fixed or random effects models according to the heterogeneity status. Subgroup analyses, meta-regression models, sensitivity analysis, risk of bias, publication bias and the quality of the included studies were also evaluated. We found that vitamin D supplementation had considerable effect on sCTX (MD: -0·038, n 22) and OC (MD: -0·610, n 24) with high heterogeneity and uNTX (MD: -8·188, n 6) without heterogeneity. Our results showed that age, sample size, dose, duration, baseline vitamin D level, study region and quality of studies might be sources of heterogeneity in this meta-analysis. Subgroup analysis also revealed significant reductions in P1NP level in dose less than 600 µg/d and larger study sample size (>100 participants). Moreover, no significant change was found in BALP level. Vitamin D supplementation/fortification significantly reduced bone resorption markers in women. However, results were inconsistent for bone formation markers.

No benefit of vitamin D supplementation on muscle function and health-related quality of life in primary cardiovascular prevention patients with statin-associated muscle symptoms: A randomized controlled trial.

BACKGROUND: Statins are the leading lipid-lowering drugs, reducing blood cholesterol by controlling its synthesis. Side effects are linked to the use of statins, in particular statin-associated muscle symptoms (SAMS). Some data suggest that vitamin D supplementation could reduce SAMS. OBJECTIVE: The purpose of this study was to evaluate the potential benefits of vitamin D supplementation in a randomized controlled trial. METHODS: Men (n = 23) and women (n = 15) (50.5 ± 7.7 years [mean ± SD]) in primary cardiovascular prevention, self-reporting or not SAMS, were recruited. Following 2 months of statin withdrawal, patients were randomized to supplementation (vitamin D or placebo). After 1 month of supplementation, statins were reintroduced. Before and 2 months after drug reintroduction, muscle damage (creatine kinase and myoglobin) was measured. Force (F), endurance (E) and power (P) of the leg extensors (ext) and flexors (fle) and handgrip strength (FHG) were also measured with isokinetic and handheld dynamometers, respectively. The Short Form 36 Health Survey (SF-36) questionnaire and a visual analog scale (VAS) were administrated to assess participants' self-reported health-related quality of life and SAMS intensity, respectively. Repeated-measures analysis was used to investigate the effects of time, supplementation, and their interaction, according to the presence of SAMS. RESULTS: Despite no change for objective measures, subjective measures worsened after reintroduction of statins, independent of supplementation (VAS, SF-36 mental component score, all p < 0.05). However, no interaction between time and supplementation according to the presence of SAMS was observed for any variables. CONCLUSIONS: Vitamin D supplementation does not appear to mitigate SAMS.

Effect of Daily Vitamin D Supplementation on Risk of Upper Respiratory Infection in Older Adults: A Randomized Controlled Trial.

BACKGROUND: Among individuals with vitamin D deficiency, daily vitamin D supplementation appears to lower risk of acute respiratory infection. However, recent trials, in different populations and using different regimens, have yielded null results. We investigated the effect of daily vitamin D supplementation (vs placebo) on risk of upper respiratory infection (URI) in older adults. METHODS: The VITamin D and OmegA-3 TriaL (VITAL) is a randomized, double-blind, placebo-controlled trial of supplemental vitamin D and/or omega-3 fatty acids in generally healthy men (age ≥50 years) and women (age ≥55 years). This prespecified analysis focuses on vitamin D3 (2000 IU/day) versus placebo in the 15 804 (61%) participants with baseline serum total 25-hydroxyvitamin D level. The primary outcome was self-report of a recent URI at 1-year follow-up. RESULTS: Participants had a mean age of 68 years and 51% were women; 76% were non-Hispanic White, 16% Black, and 8% other race/ethnicity. The mean 25-hydroxyvitamin D level at baseline was 31 (standard deviation, 10) ng/mL, with <12 ng/mL in 2.4%. The overall effect of vitamin D supplementation on recent URI was nonsignificant (odds ratio [OR], 0.96 [95% confidence interval {CI}, .86-1.06]). In the prespecified subgroup of primary interest (<12 ng/mL and denied taking concurrent vitamin D), which had only 255 participants, vitamin D supplementation was nonsignificant (OR, 0.60 [95% CI, .28-1.30]). Statistical power to assess effect modification in other subgroups was limited. CONCLUSIONS: In older adults not selected for vitamin D deficiency, supplemental vitamin D did not lower URI risk overall. Whether effects differ in subgroups requires further study. Clinical Trials Registration. NCT01169259.