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1.  Significant Effects of Oral Phenylbutyrate and Vitamin D3 Adjunctive Therapy in Pulmonary Tuberculosis: A Randomized Controlled Trial 
PLoS ONE  2015;10(9):e0138340.
Development of new tuberculosis (TB) drugs and alternative treatment strategies are urgently required to control the global spread of TB. Previous results have shown that vitamin D3 (vitD3) and 4-phenyl butyrate (PBA) are potent inducers of the host defense peptide LL-37 that possess anti-mycobacterial effects.
To examine if oral adjunctive therapy with 5,000IU vitD3 or 2x500 mg PBA or PBA+vitD3 to standard chemotherapy would lead to enhanced recovery in sputum smear-positive pulmonary TB patients.
Adult TB patients (n = 288) were enrolled in a randomized, double-blind, placebo-controlled trial conducted in Bangladesh. Primary endpoints included proportions of patients with a negative sputum culture at week 4 and reduction in clinical symptoms at week 8. Clinical assessments and sputum smear microscopy were performed weekly up to week 4, fortnightly up to week 12 and at week 24; TB culture was performed at week 0, 4 and 8; concentrations of LL-37 in cells, 25-hydroxyvitamin D3 (25(OH)D3) in plasma and ex vivo bactericidal function of monocyte-derived macrophages (MDM) were determined at week 0, 4, 8, 12 and additionally at week 24 for plasma 25(OH)D3.
At week 4, 71% (46/65) of the patients in the PBA+vitD3-group (p = 0.001) and 61.3% (38/62) in the vitD3-group (p = 0.032) were culture negative compared to 42.2% (27/64) in the placebo-group. The odds of sputum culture being negative at week 4 was 3.42 times higher in the PBA+vitD3-group (p = 0.001) and 2.2 times higher in vitD3-group (p = 0.032) compared to placebo. The concentration of LL-37 in MDM was significantly higher in the PBA-group compared to placebo at week 12 (p = 0.034). Decline in intracellular Mtb growth in MDM was earlier in the PBA-group compared to placebo (log rank 11.38, p = 0.01).
Adjunct therapy with PBA+vitD3 or vitD3 or PBA to standard short-course therapy demonstrated beneficial effects towards clinical recovery and holds potential for host-directed-therapy in the treatment of TB.
Trial Registration NCT01580007
PMCID: PMC4578887  PMID: 26394045
2.  L-arginine and Vitamin D Adjunctive Therapies in Pulmonary Tuberculosis: A Randomised, Double-Blind, Placebo-Controlled Trial 
PLoS ONE  2013;8(8):e70032.
Vitamin D (vitD) and L-arginine have important antimycobacterial effects in humans. Adjunctive therapy with these agents has the potential to improve outcomes in active tuberculosis (TB).
In a 4-arm randomised, double-blind, placebo-controlled factorial trial in adults with smear-positive pulmonary tuberculosis (PTB) in Timika, Indonesia, we tested the effect of oral adjunctive vitD 50,000 IU 4-weekly or matching placebo, and L-arginine 6.0 g daily or matching placebo, for 8 weeks, on proportions of participants with negative 4-week sputum culture, and on an 8-week clinical score (weight, FEV1, cough, sputum, haemoptysis). All participants with available endpoints were included in analyses according to the study arm to which they were originally assigned. Adults with new smear-positive PTB were eligible. The trial was registered at NCT00677339.
200 participants were enrolled, less than the intended sample size: 50 received L-arginine + active vitD, 49 received L-arginine + placebo vit D, 51 received placebo L-arginine + active vitD and 50 received placebo L-arginine + placebo vitD. According to the factorial model, 99 people received arginine, 101 placebo arginine, 101 vitamin D, 99 placebo vitamin D. Results for the primary endpoints were available in 155 (4-week culture) and 167 (clinical score) participants. Sputum culture conversion was achieved by week 4 in 48/76 (63%) participants in the active L-arginine versus 48/79 (61%) in placebo L-arginine arms (risk difference −3%, 95% CI −19 to 13%), and in 44/75 (59%) in the active vitD versus 52/80 (65%) in the placebo vitD arms (risk difference 7%, 95% CI −9 to 22%). The mean clinical outcome score also did not differ between study arms. There were no effects of the interventions on adverse event rates including hypercalcaemia, or other secondary outcomes.
Neither vitD nor L-arginine supplementation, at the doses administered and with the power attained, affected TB outcomes.
Registry Registry number: NCT00677339
PMCID: PMC3743888  PMID: 23967066
3.  Prenatal high-dose vitamin D3 supplementation has balanced effects on cord blood Th1 and Th2 responses 
Nutrition Journal  2016;15:75.
Antenatal vitamin D3 (vitD3) supplementation significantly increases maternal and neonatal 25-hydroxyvitamin D3 (25(OH)D3) concentration, yet the effect of an improvement in maternal-fetal vitamin D status on the neonatal immune response is unclear.
To assess the effect of prenatal vitD3 supplementation on cord blood T cell function, healthy pregnant Bangladeshi women (n = 160) were randomized to receive either oral 35,000 IU/week vitD3 or placebo from 26 to 29 weeks of gestation to delivery. In a subset of participants (n = 80), cord blood mononuclear cells (CBMC) were cultured, non-adherent lymphocytes were isolated to assess T cell cytokine responses to phytohemagglutinin (PHA) and anti-CD3/anti-CD28 (iCD3/iCD28), measured by multiplex assay. In 12 participants, lymphocyte gene expression profiles were analyzed by PCR array.
In supplemented group, increased concentrations of IL-10 (P < 0.000) and TNF-α (P = 0.05) with iCD3/iCD28 stimulation and IFN-γ (p = 0.05) with PHA stimulation were obtained compared to placebo group. No differences in the gene expression profile were noted between the two groups. However, PHA stimulation significantly induced the expression of genes encoding Th1 and Th2 cytokines and down-regulated a number of genes involved in T-cell development, proliferation and differentiation of B cells, signal transduction pathway, transcriptional regulation and pattern recognition receptors (PRRs) in the vitamin D group (vitD group).
Third-trimester high-dose vitD3 supplementation in healthy pregnant women had balanced effects on biomarkers of cord blood Th1 and Th2 responses.
Trial registration (NCT01126528).
Electronic supplementary material
The online version of this article (doi:10.1186/s12937-016-0194-5) contains supplementary material, which is available to authorized users.
PMCID: PMC4979151  PMID: 27506771
Vitamin D3; Cytokines; T lymphocytes; Neonates; Pregnant women; Cord blood
4.  Vitamin D and Cardiovascular Disease: An Appraisal of the Evidence 
Clinical chemistry  2013;60(4):600-609.
Supplementation with vitamin D (VitD) has received attention as a potential cardioprotective strategy. Biologically plausible mechanisms have been proposed to link VitD to coronary heart disease (CHD) prevention and observational studies suggest an inverse association between serum 25-hydroxyvitamin D (25OHD) concentrations and CHD. Few randomized clinical trials of VitD supplementation and CHD have been conducted, however, and no completed trial has been done with CHD as the primary pre-specified outcome.
A search was conducted in PubMed to find prospective studies on the use of vitamin D supplementation and cardiovascular risk factors (RFs) and/or cardiovascular disease. The exact search query was ((vitamin D supplement*[Title/Abstract]) AND cardiovascular [Title/Abstract]) AND prospective [Title/Abstract]. This query yielded 42 results. Randomized Controlled Trial (article type) was employed as a filter in a subsequent query with the same search terms. We review the evidence that VitD supplementation modifies coronary RFs, such as blood pressure, lipids, and glucose tolerance, and/or affects the development of clinical CHD events. We address potential sources of confounding in observational epidemiologic studies of the relationship between serum 25OHD and CHD. We also address laboratory assay issues relevant to the reliable measurement of 25OHD.
Most VitD supplementation trials have not demonstrated improvement in cardiovascular disease, but have tested relatively low doses of VitD. Thus, the evidence remains inconclusive, highlighting the need for rigorous randomized trials of higher VitD doses, with cardiovascular events as prespecified outcomes. While awaiting ongoing trial results, the recommended dietary allowances from the Institute of Medicine remain the best guidepost for nutritional requirements.
PMCID: PMC3972312  PMID: 24193116
5.  Calcium and vitamin D intakes in children: a randomized controlled trial 
BMC Pediatrics  2013;13:86.
Calcium (Ca2+) and vitamin D (VitD) play an important role in child health. We evaluated the daily intake of Ca2+ and VitD in healthy children. Moreover, we demonstrate the efficacy of Ca2+ and VitD supplementation.
Daily Ca2 + and VitD intake was evaluated in consecutive healthy children through a validated questionnaire. Subjects with <70% of dietary reference intakes (DRIs) of Ca2+ and VitD were invited to participate in a prospective randomized trial with 2 groups of nutritional intervention: Group 1, dietary counseling aiming to optimize daily Ca2+ and VitD intake plus administration of a commercially available Ca2 + and VitD supplementation product; Group 2, dietary counseling alone. At the enrollment (T0) and after 4 months (T1) serum 25(OH) Vitamin D levels were assessed.
We evaluated 150 healthy children (male 50%, mean age 10 years); at baseline a low VitD intake was observed in all subjects (median 0.79 μg/die, IQR 1.78; range 0.01-5.02); this condition was associated with Ca2+ intake <70% of the DRIs in 82 subjects (55%). At baseline serum 25(OH)D levels were low (<30 ng/ml) in all study subjects and after 4 months of nutritional intervention, a normalization of serum 25(OH)D levels (≥30 ng/ml) was observed in all children in Group 1 and in only one subject in Group 2 [Group 1: T1 33.8 ng/ml (IQR 2.5) vs Group 2: T1 24.5 ng/ml (IQR 5.2), p <0.001].
Adequate Ca2+ and VitD intakes are difficult to obtain through dietary counseling alone in pediatric subjects. Oral supplementation with of Ca2+ and VitD is a reliable strategy to prevent this condition.
Trial registration
The study was registered in Clinical Trials Protocol Registration System (ID number: NCT01638494).
PMCID: PMC3665520  PMID: 23702146
25-hydroxyvitamin D; Dietary counseling; Pediatrics; Ca2+ intake; VitD intake; Bone metabolism; Nutritional intervention; Vitamin D supplement; Vitamin D deficiency
6.  Effects of vitamin D supplementation on intestinal permeability, cathelicidin and disease markers in Crohn’s disease: Results from a randomised double-blind placebo-controlled study 
Vitamin D (vitD) supplementation may prolong remission in Crohn’s disease (CD); however, the clinical efficacy and mechanisms are unclear.
To determine changes in intestinal permeability (IP), antimicrobial peptide (AMP) concentrations and disease markers in CD, in response to vitD supplementation.
In a double-blind randomised placebo-controlled study, we assigned 27 CD patients in remission to 2000 IU/day vitD or placebo for 3 mos. We determined IP, plasma cathelicidin (LL-37 in ng/mL), human-beta-defensin-2 (hBD2 in pg/mL), disease activity (Crohn’s Disease Activity Index (CDAI)), C-reactive protein (CRP in mg/L), fecal calprotectin (µg/g), Quality of Life (QoL) and serum 25-hydroxyvitamin D (25(OH)D in nmol/L) at 0 and 3 mos.
At 3 mos., 25(OH)D concentrations were significantly higher in those whom were treated (p < 0.001). Intra-group analysis showed increased LL-37 concentrations (p = 0.050) and maintenance of IP measures in the treated group. In contrast, in the placebo group, the small bowel (p = 0.018) and gastro-duodenal permeability (p = 0.030) increased from baseline. At 3 mos., patients with 25(OH)D ≥ 75 nmol/L had significantly lower CRP (p = 0.019), higher QoL (p = 0.037), higher LL-37 concentrations (p < 0.001) and non-significantly lower CDAI scores (p = 0.082), compared to those with levels <75 nmol/L.
Short-term treatment with 2000 IU/day vitD significantly increased 25(OH)D levels in CD patients in remission and it was associated with increased LL-37 concentrations and maintenance of IP. Achieving 25(OH)D ≥ 75 nmol/l was accompanied by higher circulating LL-37, higher QoL scores and reduced CRP. Registered at (NCT01792388).
PMCID: PMC4480538  PMID: 26137304
Barrier function; calprotectin; cathelicidin; Crohn’s disease; human beta defensin 2; intestinal permeability; quality of life; vitamin D
7.  Prognostic Role of Vitamin D Status and Efficacy of Vitamin D Supplementation in Cancer Patients: A Systematic Review 
The Oncologist  2011;16(9):1215-1227.
Whether or not hypovitaminosis D can influence the prognosis of cancer patients and whether or not vitamin D supplementation improves outcome were examined through a literature review. It was concluded that the currently available evidence is insufficient to recommend vitamin D supplementation in cancer patients in clinical practice.
Whether or not hypovitaminosis D can influence the prognosis of cancer patients and whether or not vitamin D (vitD) supplementation improves outcome remain controversial.
Studies evaluating the prognostic role of vitD and vitD receptor (VDR) in cancer patients and trials evaluating the efficacy of vitD administration on patient outcome were identified by a search of MEDLINE, EMBASE, ISI Web of Knowledge, and the Cochrane Library through June 2010.
Twenty-five studies were included. A negative prognostic role for low serum vitD level was observed in five cohort studies including patients with breast cancer (one study), colon cancer (two studies), prostate cancer (one study), and melanoma (one study), but not in two studies on non-small cell lung cancer and one study on breast cancer. Three of four studies showed that VDR+ tumors carry a better prognosis than VDR− tumors, whereas VDR polymorphisms were significantly associated with prognosis in five of 10 studies. A significant interaction between serum vitD level and VDR polymorphism was observed in one study. Three randomized trials involving advanced prostate cancer patients explored the prognostic role of vitD supplementation. A meta-analysis of these trials showed no effect on survival (pooled risk ratio, 1.07; 95% confidence interval, CI, 0.93–1.23), with strong heterogeneity among studies.
Hypovitaminosis D seems to be associated with a worse prognosis in some cancers, but vitD supplementation failed to demonstrate a benefit in prostate cancer patients. The currently available evidence is insufficient to recommend vitD supplementation in cancer patients in clinical practice.
PMCID: PMC3228169  PMID: 21835895
Vitamin D; Vitamin D receptor; Neoplasm; Prognosis
8.  Seasonal variation of serum 25-hydroxyvitamin D levels in adult patients with inflammatory bowel disease 
Osteoporosis International  2010;22(11):2857-2867.
Patients with inflammatory bowel disease (IBD) are at risk of osteoporosis. Vitamin D (vitD) deficiency is known as a risk factor of osteoporosis. We observed low vitD blood levels in adult IBD patients both at the end of summer and winter. Furthermore, effects of oral vitD supplementation in (generally low) daily dosages were poor.
Patients with IBD are at risk of osteoporosis. This study evaluates seasonal vitD status, determinants of vitD deficiency and effects of vitD supplementation in adult IBD patients.
Patients were screened for vitD deficiency at the end of summer and winter using serum 25OHD3 (cut-off point, <50 nmol/L) combined with routine laboratory tests. A standardized questionnaire was used for demographic/lifestyle data i.e. IBD activity, health behaviour and vitD intake through diet and ultraviolet light.
Late-summer, 39% of the included 316 patients were vitD deficient. Late-winter, 57% of the follow-up patients (n = 281) were deficient. Independent protective determinants of vitD deficiency were oral vitD supplementation (summer/winter: odds ratio [OR], 0.52 [95% confidence interval [CI], 0.29–0.94]/OR, 0.44 [95% CI, 0.26–0.75]), recent sun holiday (summer: OR, 0.42 [95% CI, 0.24–0.74]) and regular solarium visits (summer/winter: OR, 0.28 [95% CI, 0.13–0.63]/OR, 0.17 [0.06–0.50]). IBD activity (p = 0.031), red blood cell distribution width (RDW; p = 0.04) and erythrocyte sedimentation rate (p = 0.03) were associated with low vitD levels using univariate analyses of the extreme 25OHD quartiles. In a subgroup with vitD supplementation, still 30% (late-summer) and 44% (late-winter) were vitD deficient.
VitD deficiency is common in IBD patients, but prevalence might be comparable with the general population. Ultraviolet light is essential for adequate vitD levels. Effects of oral vitD supplementation in (generally low) daily dosages are poor. Determinants for low vitD levels were IBD activity and elevated inflammatory markers, suggesting that increased risk of osteoporosis in IBD might be more related to the inflammation than to vitD deficiency.
PMCID: PMC3186887  PMID: 21113577
Inflammatory bowel disease; Osteoporosis; Pathophysiology; Prevalence; Seasonal variation; Serum 25-hydroxyvitamin D
9.  High-Dose Vitamin D and Calcium Attenuates Bone Loss with Antiretroviral Therapy Initiation 
Annals of internal medicine  2015;162(12):815-824.
Antiretroviral therapy (ART) initiation for HIV-1 infection is associated with 2-6% loss in bone mineral density (BMD).
To evaluate vitamin D3 (4000 IU daily) plus calcium (1000 mg calcium carbonate daily) supplementation on bone loss associated with ART initiation.
48-week prospective, randomized, double-blind, placebo-controlled study.
Thirty nine AIDS Clinical Trials Network research units.
ART-naïve HIV-infected adults.
BMD by dual-energy X-ray absorptiometry (DXA); 25-hydroxy vitamin D (25(OH)D) levels, parathyroid hormone (PTH), phosphate metabolism, markers of bone turnover and systemic inflammation.
165 eligible subjects were randomized (79 Vitamin D/calcium (VitD/Cal); 86 placebo); 142 subjects with evaluable DXA data were included in the primary analysis. The study arms were well-balanced at baseline: median age 33 years; 90% male; 33% non-Hispanic black; median CD4 count 341 cells/mm3; and median 25(OH)D 23 ng/mL (57 nmol/L). At 48 weeks, subjects receiving placebo had greater decline in total hip BMD than VitD/Cal: −3.19% median change (1st-3rd quartile (Q1, Q3) −5.12%, −1.02%) vs. (−1.46% −3.16%,−0.40%). respectively (p=0.001). Lumbar spine BMD loss for the two groups was similar: −2.91% (−4.84%, −1.06%) vs. −1.41% (−3.78%, 0.00%), (p=0.085). At week 48, 90% of participants achieved HIV-1 RNA <50 copies/mL. Levels of 25(OH)D3 increased in the VitD/Cal but not the placebo group: median change of 24.5 (14.6, 37.8) vs. 0.7 (−5.3, 4.3) ng/mL, respectively (p<0.001). Additionally, increases in markers of bone turnover were blunted in the VitD/Cal group.
No international sites were included; only 48 weeks of follow up
Vitamin D/calcium supplementation mitigates the loss of BMD seen with initiation of efavirenz/emtricitabine/tenofovir, particularly at the total hip, which is the site of greatest concern for fragility fracture.
Primary Funding Source
National Institute of Allergy and Infectious Diseases, Bristol-Meyers Squibb, Gilead Sciences.
PMCID: PMC4608553  PMID: 26075752
10.  Impact of vitamin D supplementation during a resistance training intervention on body composition, muscle function, and glucose tolerance in overweight and obese adults 
Background & Aims
The impact of vitamin D supplementation in overweight and obese adults during resistance training on body composition, muscle function, and glucose tolerance was investigated.
Twenty-three overweight and obese (age: 26.1±4.7 y; BMI: 31.3±3.2 kg/m2; 25-hydroxyvitamin D: 19.3±7.2 ng/mL) adults were recruited for participation in a double-blind, placebo-controlled trial. Participants were randomly divided into vitamin D (VitD, 4000 IU/d; 5 female, 5 male) and placebo (PL; 7 female, 6 male) groups. Both groups completed 12 wks of resistance training. 25-hydroxyvitamin D, parathyroid hormone, body composition, and glucose tolerance were assessed at baseline and 12 wks. Muscle function (strength and power) was assessed at baseline, 4, 8, and 12 wks.
During the intervention, 25-hydroxyvitamin D increased and parathyroid hormone decreased in the VitD group (P<0.05). Peak power was significantly increased at 4 wks in the VitD group only (P<0.05). Regression analysis revealed an inverse association between the change in 25-hydroxyvitamin D with the change in waist-to-hip ratio (R2=0.205, P=0.02). No other improvements were observed with supplementation.
Vitamin D supplementation in overweight and obese adults during resistance training induced an early improvement in peak power, and elevated vitamin D status was associated with reduced waist-to-hip ratio.
Clinical trial registration number
PMCID: PMC4365291  PMID: 23034474
25-hydroxyvitamin D; parathyroid hormone; lean mass; muscular strength; muscular power
Suboptimal vitamin D (vitD) status (<32 ng/ml) is ubiquitous among African American children with type SS sickle cell disease (SCD-SS). The vitD supplemental dose to normalize vitD status is unknown. Five to 20-year-old African-American children with (n=21) and without (n=23) SCD-SS were randomized to vitD3 supplementation (4,000 or 7,000 IU/day) and evaluated at 6- and 12-weeks for changes in vitD and SCD status. A dose was considered unsafe if serum calcium was elevated associated with elevated serum 25 hydroxyvitamin D (25(OH)D)). At baseline 95% of subjects with SCD-SS and 87% of healthy controls had suboptimal vitD status (mean ± SD, 19.2 ± 7.2 and 22.3 ± 9.3 ng/ml, respectively). After 12-weeks supplementation, both D3 doses were safe and well tolerated. Neither group achieved the a priori efficacy criterion of 25(OH)D ≥ 32 ng/ml in >80% of subjects (45% in SCD-SS and 63% in controls). However for both subjects with SCD-SS and healthy subjects by 12-weeks, deficient (< 20 ng/ml) vitD status was eliminated only in those receiving 7,000 IU/d. For subjects with SCD-SS, by 12-weeks there was a significant (all P<0.05) increase in fetal hemoglobin, decrease in HS-CRP, and reduction in the percentage of subjects with a high platelet count.
PMCID: PMC4474739  PMID: 25985241
Vitamin D; Sickle Cell Disease; Pediatrics; Supplementation
12.  Vitamin D Status and Rates of Cognitive Decline in a Multiethnic Cohort of Older Adults 
JAMA neurology  2015;72(11):1295-1303.
Vitamin D (VitD) deficiency is associated with brain structural abnormalities, cognitive decline, and incident dementia.
To assess associations between VitD status and trajectories of change in subdomains of cognitive function in a cohort of ethnically diverse older adults.
Longitudinal multiethnic cohort study of 382 participants in an outpatient clinic enrolled between February 2002 and August 2010 with baseline assessment and yearly follow-up visits. Serum 25-hydroxyvitamin D (25-OHD) was measured, with VitD status defined as the following: deficient, less than 12 ng/mL (to convert to nanomoles per liter, multiply by 2.496); insufficient, 12 to less than 20 ng/mL; adequate, 20 to less than 50 ng/mL; or high, 50 ng/mL or higher. Subdomains of cognitive function were assessed using the Spanish and English Neuropsychological Assessment Scales. Associations were evaluated between 25-OHD levels (as continuous and categorical [deficient, insufficient, or adequate]) and trajectories of cognitive decline.
Serum 25-OHD levels, cognitive function, and associations between 25-OHD levels and trajectories of cognitive decline.
Participants (N = 382 at baseline) had a mean (SD) age of 75.5 (7.0) years; 61.8% were women; and 41.4% were white, 29.6% African American, 25.1% Hispanic, and 3.9% other race/ethnicity. Diagnosis at enrollment included 17.5% with dementia, 32.7% with mild cognitive impairment, and 49.5% cognitively normal. The mean (SD) 25-OHD level was 19.2 (11.7) ng/mL, with 26.2% of participants being VitD deficient and 35.1% insufficient. The mean (SD) 25-OHD levels were significantly lower for African American and Hispanic participants compared with white participants (17.9 [15.8] and 17.2 [8.4] vs 21.7 [10.0] ng/mL, respectively; P < .001 for both). The mean (SD) 25-OHD levels were similarly lower in the dementia group compared with the mild cognitive impairment and cognitively normal groups (16.2 [9.4] vs 20.0 [10.3] and 19.7 [13.1] ng/mL, respectively; P = .006). The mean (SD) follow-up was 4.8 (2.5) years. Rates of decline in episodic memory and executive function among VitD-deficient (episodic memory: β = −0.04 [SE = 0.02], P = .049; executive function: β = −0.05 [SE = 0.02], P = .01) and VitD-insufficient (episodic memory: β = −0.06 [SE = 0.02], P < .001; executive function: β = −0.04 [SE = 0.02], P = .008) participants were greater than those with adequate status after controlling for age, sex, education, ethnicity, body mass index, season of blood draw, vascular risk, and apolipoprotein E4 genotype. Vitamin D status was not significantly associated with decline in semantic memory or visuospatial ability. Exclusion of participants with dementia did not substantially affect the associations between VitD status and rates of cognitive decline.
Low VitD status was associated with accelerated decline in cognitive function domains in ethnically diverse older adults, including African American and Hispanic individuals who exhibited a high prevalence of VitD insufficiency or deficiency. It remains to be determined whether VitD supplementation slows cognitive decline.
PMCID: PMC5023277  PMID: 26366714
13.  Decreased Serum Vitamin D Levels in Children with Asthma are Associated with Increased Corticosteroid Usage 
There is little knowledge about clinical variables associated with vitamin D (vitD) insufficiency in asthmatic children.
To investigate disease variables associated with vitD insufficiency in childhood asthma and interaction of vitD with corticosteroid-mediated anti-inflammatory responses.
We analyzed 25-hydroxyvitamin D serum levels in 100 asthmatic children to investigate relationships between 25-hydroxyvitamin D levels and patient characteristics. We determined vitD effects on dexamethasone (DEX) induction of mitogen-activated protein kinase phosphatase-1 (MKP-1) and IL-10 in peripheral blood mononuclear cells (PBMC).
The median 25-hydroxyvitamin D serum level was 31 ng/mL. 47% of subjects had vitD levels in the insufficient range (<30 ng/mL), while 17% were vitD deficient (<20 ng/mL). Log10 IgE (p=0.01, ρ=−0.25) and the number of positive aeroallergen skin prick tests (p=0.02, ρ=−0.23) showed a significant inverse correlation with vitD, whereas FEV1% predicted (p =0.004, ρ=0.34) and FEV1/FVC ratio (p=0.01, ρ=0.30) showed a significant positive correlation with vitD. The use of inhaled steroids (p=0.0475), oral steroids (p=0.02), and total steroid dose (p=0.001), all showed significant inverse correlations with vitD. The amount of MKP-1 and IL-10 mRNA induced by vitD plus DEX was significantly greater than that induced by DEX alone (p<0.01). In an experimental model of steroid resistance where DEX alone did not inhibit T cell proliferation, addition of vitD to DEX resulted in significant dose dependent suppression of cell proliferation.
Corticosteroid use and worsening airflow limitation is associated with lower vitD serum levels in asthmatics. VitD enhances glucocorticoid action in asthmatic PBMC and enhances the immunosuppressive function of DEX in vitro.
Clinical Implications
Our study suggests that vitD supplementation may potentiate anti-inflammatory function of corticosteroids in asthmatics and thereby improve asthma control.
PMCID: PMC2866800  PMID: 20381849
vitamin D; children; asthma
14.  Safety and Efficacy of High-Dose Daily Vitamin D3 Supplementation in Children and Young Adults Infected With Human Immunodeficiency Virus 
Suboptimal vitamin D (vitD) status is common in children and young adults infected with human immunodeficiency virus (HIV). The vitD supplemental dose needed to normalize vitD status in this population is unknown.
In this double-blind trial, subjects infected with HIV ages 8.3 to 24.9 years were randomized to vitD3 supplementation of 4000 IU/day or 7000 IU/day and evaluated at 6 and 12 week for changes in vitD status and HIV indicators. A dose was considered unsafe if serum calcium was elevated (above age and sex-specific range) associated with elevated serum 25 hydroxyvitamin D (25(OH)D); >160 ng/mL).
At baseline, 95% of subjects (n = 44; 43% with perinatally acquired HIV, 57% with behaviorally acquired HIV) had a suboptimal serum 25(OH)D concentration of <32 ng/mL (mean ± standard deviation, 19.3 ± 7.4; range, 4.4–33.6 ng/mL). After 12 weeks (main outcome) of D3 supplementation, both D3 doses were safe and well tolerated, with no evidence of elevation of serum calcium concentrations or deterioration in HIV immunologic or virologic status. Sufficient vitD status, defined as serum 25(OH)D ≥32 ng/mL, was achieved in 81% of all subjects, and only the 7000 IU/day group (86%) achieved this a priori efficacy criterion in >80% of subjects. Change in serum 25(OH)D did not differ between HIV acquisition groups.
A 7000 IU/day D3 supplementation was safe and effective in children and young adults infected with HIV.
PMCID: PMC4854371  PMID: 26625449
HIV; nutrition; pediatrics; supplementation; vitamin D.
15.  High-Dose Vitamin D3 Supplementation in Children and Young Adults with HIV: A Randomized, Placebo-Controlled Trial 
Suboptimal vitamin D status is prevalent in HIV-infected patients and associated with increased risk of disease severity and morbidity. We aimed to determine 12-mo safety and efficacy of daily 7000IU vitamin D3 (vitD3) vs placebo to sustain increased serum 25-hydroxyvitamin D (25(OH)D) and improve immune status in HIV-infected subjects.
This was a double-blind trial of perinatally- (PHIV) or behaviorally-acquired (BHIV) HIV-infected subjects (5.0–24.9y). Safety, 25(OH)D-related parameters, and immune status were assessed at baseline, 3, 6, and 12 months.
Fifty-eight subjects enrolled (67% male, 85% African-American, 64% BHIV) and 50 completed with no safety concerns. In unadjusted analyses, there were no differences between randomization groups at baseline; at 3, 6, and 12 months, 25(OH)D was higher with supplementation than baseline and higher than with placebo (P<0.05). In adjusted mixed models, in the supplementation group, the fixed effect of 25(OH)D was higher (P<0.001). Percentage of naïve T helper cells (Th naïve%) were significantly (P<0.01) and T helper cells (CD4%) marginally (P<0.10) increased with supplementation in those taking highly active antiretroviral therapy (HAART), and RNA viral load was reduced (P ≤ 0.05). In exploratory linear models, change in 25(OH)D predicted RNA viral load at 3 and 12 months and CD4% at 3 months (P<0.05).
Daily 7000IU vitD3 for 12 months was safe in HIV-infected subjects and effective in increasing 25(OH)D. Supplementation improved in some clinically important HIV immune markers in subjects on HAART. Adjunct therapy with high-dose, daily vitD3 for HIV-infected subjects and for those on/off HAART requires further investigation.
PMCID: PMC4281504  PMID: 24988118
Vitamin D3 supplementation; pediatric HIV; cholecalciferol; nutrition
16.  Risk of Prostate Cancer in African American Men: Evidence of Mixed Effects of Dietary Quercetin by Serum Vitamin D Status 
The Prostate  2015;75(13):1376-1383.
African American (AA) men experience higher rates of prostate cancer (PCa) and vitamin D (vitD) deficiency than white men. VitD is promoted for PCa prevention, but there is conflicting data on the association between vitD and PCa. We examined the association between serum vitD and dietary quercetin and their interaction with PCa risk in AA men.
Participants included 90 AA men with PCa undergoing treatment at Howard University Hospital (HUH) and 62 controls participating in HUH’s free PCa screening program. We measured serum 25-hydroxy vitD [25(OH)D] and used the 98.2 item Block Brief 2000 Food Frequency Questionnaires to measure dietary intake of quercetin and other nutrients. Case and control groups were compared using two-sample t test for continuous risk factors and Fisher exact test for categorical factors. Associations between risk factors and PCa risk were examined via age-adjusted logistic regression models.
Interaction effects of dietary quercetin and serum vitD on PCa status were observed. AA men (age 40–70) with normal levels of serum vitD (> 30 ng/ml) had a 71% lower risk of PCa compared to AA men with vitD deficiency (OR=0.29, 95% CI: 0.08–1.03; p=0.055). In individuals with vitD deficiency, increased dietary quercetin showed a tendency toward lower risk of PCa (OR=0.91, 95% CI: 0.82–1.00; p=0.054, age-adjusted) while men with normal vitD were at elevated risk (OR=1.23, 95% CI: 1.04–1.45).
These findings suggest that AA men who are at a higher risk of PCa may benefit more from vitD intake, and supplementation with dietary quercetin may increase the risk of PCa in AA men with normal vitD levels. Further studies with larger populations are needed to better understand the impact of the interaction between sera vitD levels and supplementation with quercetin on PCa in AA men.
PMCID: PMC4536082  PMID: 26047130
Vitamin D; Quercetin; Prostate cancer; African American
17.  The Association of Concurrent Vitamin D and Sex Hormone Deficiency with Bone Loss and Fracture Risk in Older Men: The MrOS Study 
Low 25-hydroxyvitamin D (VitD), low sex hormones (SH), and high sex hormone binding globulin (SHBG) levels are common in older men. We tested the hypothesis that combinations of low VitD, low SH, and high SHBG would have a synergistic effect on bone mineral density (BMD), bone loss, and fracture risk in older men. Participants were a random subsample of 1468 men (mean age 74) from the Osteoporotic Fractures in Men Study (MrOS) plus 278 MrOS men with incident non-spine fractures studied in a case-cohort design. “Abnormal” was defined as lowest quartile for VitD (<20 ng/ml), bioavailable testosterone (BioT, <163 ng/dl), and bioavailable estradiol (BioE, <11 pg/ml); and highest quartile for SHBG (>59 nM).
Overall, 10% had isolated VitD deficiency; 40% had only low SH or high SHBG; 15% had both SH/SHBG and VitD abnormality, and 35% had no abnormality. Compared to men with all normal levels, those with both SH/SHBG and VitD abnormality tended to be older, more obese, and to report less physical activity. Isolated VitD deficiency, and low BioT with or without low VitD, was not significantly related to skeletal measures. The combination of VitD deficiency with low BioE and/or high SHBG was associated with significantly lower baseline BMD and higher annualized rates of hip bone loss than SH abnormalities alone or no abnormality. Compared to men with all normal levels, the multivariate-adjusted hazard ratio (95% CI) for incident non-spine fracture during 4.6 yr median follow-up was 1.2 (0.8–1.8) for low VitD alone; 1.3 (0.9–1.9) for low BioE and/or high SHBG alone; and 1.6 (1.1–2.5) for low BioE/high SHBG plus low VitD.
In summary, adverse skeletal effects of low sex steroid levels were most pronounced in older men with low VitD levels. The presence of low VitD in the presence of low BioE/high SHBG may contribute substantially to poor skeletal health.
PMCID: PMC3474871  PMID: 22777902
bone loss; fracture; older men; sex hormones; vitamin
18.  Vitamin D Status and Related Factors in Newborns in Shanghai, China 
Nutrients  2014;6(12):5600-5610.
With the increasing recognition of the importance of the non-skeletal effects of vitamin D (VitD), more and more attention has been drawn to VitD status in early life. However, the VitD status of newborns and factors that influence VitD levels in Shanghai, China, remain unclear. A total of 1030 pregnant women were selected from two hospitals in Shanghai, one of the largest cities in China located at 31 degrees north latitude. Umbilical cord serum concentrations of 25-hydroxy vitamin D [25(OH)D] were measured by LC-MS-MS, and questionnaires were used to collect information. The median cord serum 25(OH)D concentration was 22.4 ng/mL; the concentration lower than 20 ng/mL accounted for 36.3% of the participants, and the concentration lower than 30 ng/mL for 84.1%. A multivariable logistic regression model showed that the determinants of low 25(OH)D status were being born during autumn or winter months and a lack of VitD-related multivitamin supplementation. The relative risk was 1.7 for both autumn (95% CI, 1.1–2.6) and winter (95% CI, 1.1–2.5) births (p < 0.05). VitD-related multivitamin supplementation more than once a day during pregnancy reduced the risk of VitD deficiency [adjusted OR (aOR) = 0.6, 95% CI (0.45–1.0) for VitD supplementation] (p < 0.05). VitD deficiency and insufficiency are common in newborns in Shanghai, China, and are independently associated with season and VitD supplementation. Our findings may assist future efforts to correct low levels of 25(OH)D in Shanghai mothers and their newborn children.
PMCID: PMC4276986  PMID: 25486368
vitamin D; related factors; newborn
19.  Vitamin D3 Decreases Parathyroid Hormone in HIV-Infected Youth Being Treated With Tenofovir: A Randomized, Placebo-Controlled Trial 
In this randomized, double-blind, placebo-controlled trial of human immunodeficiency virus–infected youths aged 18–25, vitamin D3, 50000 IU once monthly for 3 months decreased parathyroid hormone in participants treated with tenofovir-containing antiretroviral regimens but not in those participants whose regimens did not contain tenofovir.
Background. The study goal was to determine the effect of vitamin D (VITD) supplementation on tubular reabsorption of phosphate (TRP), parathyroid hormone (PTH), bone alkaline phosphatase (BAP), and C-telopeptide (CTX) in youth infected with human immunodeficiency virus (HIV) receiving and not receiving combination antiretroviral therapy (cART) containing tenofovir disoproxil fumarate (TDF).
Methods. This randomized, double-blind, placebo-controlled multicenter trial enrolled HIV-infected youth 18–25 years based on stable treatment with cART containing TDF (n = 118) or no TDF (noTDF; n = 85), and randomized within those groups to vitamin D3, 50 000 IU (n = 102) or placebo (n = 101), administered at 0, 4, and 8 weeks. Outcomes included change in TRP, PTH, BAP, and CTX from baseline to week 12 by TDF/noTDF; and VITD/placebo.
Results. At baseline, VITD and placebo groups were similar except those on TDF had lower TRP and higher PTH and CTX. At week 12, 95% in the VITD group had sufficient serum 25-hydroxy vitamin D (25-OHD; ≥20 ng/mL), increased from 48% at baseline, without change in placebo (P < .001). PTH decreased in the TDF group receiving VITD (P = .031) but not in the noTDF group receiving VITD, or either placebo group. The decrease in PTH with VITD in those on TDF occurred with insufficient and sufficient baseline 25-OHD (mean PTH change, −7.9 and −6.2 pg/mL; P = .031 and .053, respectively).
Conclusions. In youth on TDF, vitamin D3 supplementation decreased PTH, regardless of baseline 25-OHD concentration.
Clinical Trials Registration. NCT00490412.
PMCID: PMC3297650  PMID: 22267714
20.  Association of Leptin, 25-Hydroxyvitamin D, and Parathyroid Hormone in Women 
Nutrition and cancer  2009;61(2):225-231.
Vitamin D deficiency and adipocytokines have been implicated in the etiology of aging-related diseases such as cancer, osteoporosis, and diseases of the cardiovascular system. The association between elevated parathyroid hormone (PTH) and low 25-hydroxyvitamin D(25-OH-VitD) in plasma is used to define vitamin D deficiency, yet their associated mechanistic pathways are unclear. Utilizing plasma samples from women in a previous intervention study, we measured plasma 25-OH-VitD, leptin, adiponectin, PTH, and lipid levels. We observed strong positive associations for leptin with PTH, γ-tocopherol, and body mass index (BMI) and inverse associations with 25-OH-VitD and adiponectin. Although commonly accepted that vitamin D deficiency causes hyperparathyroidism, we observed this association primarily in individuals with elevated leptin levels, suggesting that leptin may be an important modifier of this effect consistent with 25-OH-VitD-mediated inhibition of leptin. Leptin was highly correlated with the BMI/25-OH-VitD ratio (r = 0.80; P < 0.0001), consistent with a model in which BMI (adiposity) and 25-OH-VitD are the primary determinants of circulating leptin and PTH levels. This model may explain the failure of some studies to observe elevated PTH in vitamin D deficient adolescents and provides important insight into epidemiological studies exploring the associations of these individual biomarkers with chronic disease risk and mortality.
PMCID: PMC4406327  PMID: 19235038
21.  Association of vitamin D and vitamin D receptor gene polymorphisms with chronic inflammation, insulin resistance and metabolic syndrome components in type 2 diabetic Egyptian patients 
Meta Gene  2014;2:540-556.
To date the published data concerning the possible interplay between vitamin D (VitD) and Vit D receptor (VDR) gene polymorphism with the immune/inflammatory mediators in type 2 diabetes mellitus (DM) is insufficient. Some of the immune non-classical actions of vitamin D may point to its role in the pathogenesis of type 2 DM through down-regulation of cytokines (IL-6). Although there is evidence to support a relationship among vitamin D status, chronic inflammation and insulin resistance, the underlying mechanism requires further exploration. We aimed to investigate the role of vitamin D in chronic inflammation and insulin resistance in type 2 DM. Moreover, to examine the association of VDR gene polymorphisms [VDR 2228570 C > T (FokI); VDR 1544410 A > G (BsmI)] with the components of metabolic syndrome (MetSyn) in type 2 diabetic Egyptian patients .
Subjects and methods
A total of 190 subjects were enrolled in this study, 60 controls and 130 type 2 diabetic patients (Group II). Group II was subdivided into 63 patients without MetSyn (subgroup IIa) and 67 patients with MetSyn (subgroup IIb). Genetic analysis for VDR gene polymorphisms was done in all subjects. VitD and IL-6 plasma levels were estimated.
The TT genotype for the VDR FokI was significantly more frequent in subgroup IIb than in subgroup IIa and controls (X2 = 6.83, P = 0.03 and X2 = 16.592, P = 0.000) respectively. The T allele was more frequent in the MetSyn group as compared to diabetics without MetSyn (p = 0.001), odds ratio (OR) and 95% CI for the T allele of C > T (FokI) = 2.30 (1.37–3.86). We did not detect any significant difference in VDR BsmI genotypes between patients and control groups (P = 0.947). FokI VDR was significantly associated with the lipid profile parameters, VitD and IL-6 plasma levels in subgroup IIa and associated with HOMA-IR, insulin, VitD, IL-6 levels, waist circumference (WC) and body mass index (BMI) in subgroup IIb while BsmI VDR variant was associated only with VitD values in both subgroups.
The present study suggests an interaction between VDR polymorphisms and important components of MetSyn, VitD and pro-inflammatory cytokines (IL-6). FokI VDR polymorphisms may be linked to mild inflammation and insulin resistance and might represent a genetic determinant for developing MetSyn in type 2 diabetic Egyptian patients. The challenge is determining the mechanisms of VitD action for recommendation of VitD supplementation that reduces the risks of MetSyn, insulin resistance and progression to type 2 diabetes.
PMCID: PMC4287888  PMID: 25606437
VitD, Vitamin D; DM, diabetes mellitus; VDR, Vit D receptor; MetSyn, metabolic syndrome; HOMA, Homeostasis of Metabolic Assessment; WC, waist circumference; OR, odds ratio; BMI, body mass index; IL-6, interleukin -6; SOCS, suppressors of cytokine signaling; IRS, insulin receptor substrates; CRP, C-reactive protein; FBG, fasting blood glucose; SBP, systolic blood pressure; DBP, diastolic blood pressure; HbA1c, glycated hemoglobin; FPI, fasting plasma insulin; TC, total cholesterol; TG, triglyceride; HDL-C, high density lipoprotein cholesterol; LDL-C, low density lipoprotein cholesterol; HPLC, High performance liquid chromatography; SD, standard deviation; X2, Chi-square; CI, confidence intervals; PGs, pro-inflammatory prostaglandins; NHANES III, National Health and Examination Survey; PTH, parathyroid hormone; Insulin resistance; Type 2 diabetes mellitus (DM); Metabolic syndrome; Vitamin D; Vitamin D Receptor gene; Polymorphisms; Pro-inflammatory cytokines; Interleukin-6 (IL-6)
22.  Vitamin D status of early preterm infants and the effects of vitamin D intake during hospital stay 
To evaluate vitamin D (vitD) status in early preterm infants (EPTIs) at birth and during birth hospitalisation on current vitD intake.
Serum 25-hydroxyvitamin-D [25(OH)D] concentrations, vitD intake and risk factors for low vitD status were assessed in 120 infants born at ≤32 weeks gestation.
Mean (SD) serum 25(OH)D at birth was 46.2 (14.0) nmol/L with lower concentrations in infants born <28 weeks than at 28–32 weeks gestation, p=0.02. Serum 25(OH)D was <50 nmol/L in 63% of mothers, 64% of infants at birth and 35% of infants at discharge. Mean daily vitD intake was 289±96 IU at 4 weeks of age and 60% achieved 400 IU/day intake at discharge.
Serum 25(OH)D <50 nmol/L was widespread in parturient women and in EPTIs at birth and at discharge. Optimising maternal vitD status during pregnancy and improving postnatal vitD intake may enhance infant vitD status during hospitalisation.
PMCID: PMC3933171  PMID: 23852093
Neonatology; Nutrition
23.  The Impact of Vitamin D3 Supplementation on Muscle Function among HIV-Infected Children and Young Adults: A Randomized Controlled Trial 
We tested the hypothesis that daily vitD3 supplementation increases neuromuscular motor skills, jump power, jump energy, muscular force, and muscular strength.
This was a secondary analysis of a randomized controlled trial of 12-months of oral 7,000 IU/day vitD3 supplementation or placebo among 56 persons living with HIV aged 9–25 years. Neuromuscular motor skills were quantified using the Bruininks-Oseretsky Test of Motor Proficiency. Power was quantified using peak jump power, and energy was quantified using peak jump height. Muscular force was quantified using isometric ankle plantar- and dorsiflexion, isokinetic knee flexion and extension. Muscular strength was quantified using isometric handgrip strength.
After 12-months, serum 25-hydroxyvitamin D [25(OH)D] was higher with supplementation versus placebo (β=12.1 ng/mL; P<0.001). In intention-to-treat analyses, supplementation improved neuromuscular motor skills versus placebo (β=1.14; P=0.041). We observed no effect of supplementation on jump power, jump energy, muscular force, or muscular strength outcomes versus placebo.
Among HIV-infected children and young adults supplementation with daily high-dose vitD3 increased concentration of serum 25(OH)D and improved neuromuscular motor skills versus placebo.
PMCID: PMC4533987  PMID: 26032206
vitamin D supplementation; pediatric HIV; cholecalciferol; nutrition; muscle
24.  Cardiovascular effects of cholecalciferol treatment in dialysis patients – a randomized controlled trial 
BMC Nephrology  2014;15:50.
Patients on chronic dialysis are at increased risk of vitamin D deficiency. In observational studies plasma 25-hydroxyvitamin D (p-25(OH) D) levels are inversely correlated with plasma BNP and adverse cardiovascular outcomes. Whether a causal relation exists has yet to be established. The aim of this study was to test the hypothesis that cholecalciferol supplementation improves cardiac function and reduces blood pressure (BP) and pulse wave velocity (PWV) in patients on chronic dialysis.
In a randomized, placebo-controlled, double-blind study, we investigated the effect of 75 μg (3000 IU) cholecalciferol daily for 6 months, in patients on chronic dialysis. We performed two-dimensional echocardiography, with doppler and tissue-doppler imaging, 24-h ambulatory BP (24-h BP), PWV, augmentation index (AIx), central BP (cBP) and brain natriuretic peptide (BNP) measurements at baseline and after 6 months.
Sixty-four patients were allocated to the study. Fifty dialysis patients with a mean age of 68 years (range: 46–88) and baseline p-25(OH) D of 28 (20;53) nmol/l completed the trial. Cholecalciferol increased left ventricular (LV) volume, but had no impact on other parameters regarding LV structure or left atrial structure. LV systolic function, LV diastolic function, PWV, cBP, AIx and BNP were not changed in placebo or cholecalciferol group at follow-up. 24-h BP decreased significantly in placebo group and tended to decrease in cholecalciferol group without any difference between treatments.
Six months of cholecalciferol treatment in patients on chronic dialysis did not improve 24-h BP, arterial stiffness or cardiac function.
Trial registration
NCT01312714, Registration Date: March 9, 2011.
PMCID: PMC3994388  PMID: 24661355
Cholecalciferol; Chronic kidney disease; Cardiac function; Brain natriuretic peptide; Blood pressure
25.  Vitamin D2 Supplementation Amplifies Eccentric Exercise-Induced Muscle Damage in NASCAR Pit Crew Athletes 
Nutrients  2013;6(1):63-75.
This study determined if 6-weeks vitamin D2 supplementation (vitD2, 3800 IU/day) had an influence on muscle function, eccentric exercise-induced muscle damage (EIMD), and delayed onset of muscle soreness (DOMS) in National Association for Stock Car Auto Racing (NASCAR) NASCAR pit crew athletes. Subjects were randomized to vitD2 (n = 13) and placebo (n = 15), and ingested supplements (double-blind) for six weeks. Blood samples were collected and muscle function tests conducted pre- and post-study (leg-back and hand grip dynamometer strength tests, body weight bench press to exhaustion, vertical jump, 30-s Wingate test). Post-study, subjects engaged in 90 min eccentric-based exercise, with blood samples and DOMS ratings obtained immediately after and 1- and 2-days post-exercise. Six weeks vitD2 increased serum 25(OH)D2 456% and decreased 25(OH)D3 21% versus placebo (p < 0.001, p = 0.036, respectively), with no influence on muscle function test scores. The post-study eccentric exercise bout induced EIMD and DOMS, with higher muscle damage biomarkers measured in vitD2 compared to placebo (myoglobin 252%, 122% increase, respectively, p = 0.001; creatine phosphokinase 24 h post-exercise, 169%, 32%, p < 0.001), with no differences for DOMS. In summary, 6-weeks vitD2 (3800 IU/day) significantly increased 25(OH)D2 and decreased 25(OH)D3, had no effect on muscle function tests, and amplified muscle damage markers in NASCAR pit crew athletes following eccentric exercise.
PMCID: PMC3916849  PMID: 24362707
delayed onset of muscle soreness (DOMS); myoglobin; creatine phosphokinase; muscle function testing; eccentric exercise; LC-MS/MS

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