Effects of chronic endurance exercise training on serum 25(OH)D concentrations in elderly Japanese men

Exercise without Weight Loss Prevents Seasonal Decline in Vitamin D Metabolites: The VitaDEx Randomized Controlled Trial

Many adults become vitamin D deficient or insufficient during winter at northerly latitudes when cutaneous vitamin D synthesis does not occur. Vitamin D accumulates in adipose tissue and people with overweight or obesity are more likely to have low systemic vitamin D. This randomized controlled trial demonstrates that regular exercise completely maintains serum concentrations of the active vitamin D metabolite 1,25(OH)2D3 over winter and may ameliorate the decline in 25(OH)D status in overweight men and women, even without weight loss. The binding of 1,25(OH)2D3 to the vitamin D receptor mediates the crucial role for vitamin D in the healthy function of multiple organ systems and vitamin D supplementation does not impact circulating 1,25(OH)2D3. Thus, the VitaDEx study provides causal evidence that exercise plays an important role in vitamin D metabolism that is distinct from the effects of oral supplementation.

A Personalized Approach to Vitamin D Supplementation in Cardiovascular Health Beyond the Bone: An Expert Consensus by the Italian National Institute for Cardiovascular Research

Vitamin D is increasingly recognized for its role in cardiovascular health beyond its well-established effects on bone metabolism. This review synthesizes findings from observational studies, interventional trials, and meta-analyses to clarify the mechanisms through which vitamin D impacts cardiovascular health, including its influence on vascular function, inflammation, and metabolic pathways. Additionally, this review emphasizes the importance of a personalized approach to vitamin D supplementation, integrating individual cardiovascular risk profiles, baseline vitamin D levels, and comorbid conditions, such as hypertension and diabetes. While current evidence supports the association between low vitamin D levels and increased cardiovascular mortality, this work contributes novel insights by proposing tailored strategies for supplementation, particularly for high-risk subgroups. Practical recommendations for implementing these strategies in clinical practice are also discussed, providing a framework for optimizing cardiovascular outcomes through individualized vitamin D management.

Impact of 24-week supervised concurrent exercise on S-Klotho and vitamin D levels: A randomized controlled trial

This study aimed to investigate the effects 24 weeks of supervised exercise training at different intensities on S-Klotho and 25-hydroxyvitamin D plasma levels in young adults. This report was based on a secondary analysis from the ACTIBATE single-center unblinded randomized controlled trial (ClinicalTrials.gov ID: NCT02365129). A total of 144 young adults (~34% men and ~66% women) aged between 18 and 25 years took part in the study. The participants were randomly assigned to 3 different groups: (i) concurrent exercise training program based on the international physical activity recommendations at vigorous intensity (Ex-Vigorous group), (ii) at moderate intensity (Ex-Moderate group), and (iii) control group (no exercise). S-Klotho and 25-hydroxyvitamin D plasma levels were determined before and after the 24-week intervention programme. A significant decrease of 25-hydroxyvitamin D plasma levels were identified across time in all groups (p < 0.001), whereas no significant differences across time were observed in S-Klotho plasma levels (p = 0.497). There was no time x group interaction neither in S-Klotho nor in 25-hydroxyvitamin D plasma levels (all p > 0.7). In summary, our results showed that 24 weeks of supervised concurrent exercise training does not induce significant changes on S-Klotho and 25-hydroxyvitamin D independently of the exercise intensity in young adults.

Activation of the apelin/APJ system by vitamin D attenuates age-related muscle atrophy

AIMS

Age-related frailty and reduced physical activity contribute to a degenerative loss of muscle mass, function, and strength, which is known as sarcopenia. Increasing evidence has shown that vitamin D has beneficial effects on the muscle health. However, the molecular mechanisms of vitamin D have not been fully elucidated. In this study, we aimed to demonstrate whether vitamin D can overcome muscle atrophy due to aging, especially with respect to the regulation of myokines.

MAIN METHODS

Young (3-month-old) and aged (18-month-old) C57BL/6 mice were assigned to the following 3 groups: normal diet (1000 IU/kg), vitamin D3-supplemented diet (20,000 IU/kg), and normal diet plus exercise for 4 months.

KEY FINDINGS

We found that the reduction in muscle strength and mass due to aging was reversed by vitamin D3 supplementation. The levels of markers involved in muscle atrophy and cellular senescence in the muscle of the aged mice were substantially decreased by vitamin D3. Interestingly, we observed that the expression of apelin and its receptor (APJ), which is known to be secreted after exercise, significantly increased in aged muscles with a vitamin D3-supplemented diet but not in the young mice. Moreover, circulating interleukin-6 (IL-6) and growth differentiation factor 8 (GDF8) levels were significantly increased in the aged mice but were restored by vitamin D3 treatment.

SIGNIFICANCE

Our present data indicate that vitamin D3 supplementation ameliorates aging-induced muscle atrophy and senescence, similar to the effects of exercise, suggesting the positive impact of vitamin D as an intervention strategy to prevent aging-induced metabolic diseases.

The effect of aquatic training and vitamin D3 supplementation on bone metabolism in postmenopausal obese women

Purpose

Despite prevalence of studies indicating the positive effect of land-based exercise on bone metabolism, there are limited findings regarding the effect of aquatic exercise. The present study aimed to evaluate the effects of aquatic training and vitamin D3 supplementation on femur bone mineral density (BMD), serum 25(OH)D, and parathyroid hormone (PTH) in postmenopausal obese women with vitamin D insufficiency.

Methods

40 postmenopausal obese women were randomly divided into four groups of aquatic training + vitamin D3 intake group; (ATD), aquatic training with placebo intake group (AT), vitamin D3 intake group (D), and control group with placebo intake (CON). AT groups performed aerobic aquatic exercises for 8 weeks. Vitamin D3 supplementation groups consumed oral dose of 4000 IU/d for 8 weeks.

Results

The femur BMD was significantly higher in the ATD than the AT and D and CON groups; in AT it was higher than the D and CON groups. Serum 25(OH)D level in the ATD was more than AT and CON, and in the D was more than the CON and AT. PTH in the ATD group was lower compared to AT, D, and CON groups. PTH was lower in the AT and D compared to the CON.

Conclusion

In postmenopausal obese women with vitamin D insufficiency or deficiency, combining vitamin D supplementation and aquatic training was the most effective method for improving bone metabolism; Vitamin D supplementation (alone) was not sufficient to affect some of bone metabolism indices; Aquatic training could not improve serum vitamin D. By priority, ATD, AT, and D indicated better bone related metabolism indices.

Vitamin D Supplementation: A Review of the Evidence Arguing for a Daily Dose of 2000 International Units (50 µg) of Vitamin D for Adults in the General Population

Vitamin D deficiency is considered a public health problem due to its worldwide high prevalence and adverse clinical consequences regarding musculoskeletal health. In addition, vitamin D may also be crucial for the prevention of certain extraskeletal diseases. Despite decades of intensive scientific research, several knowledge gaps remain regarding the precise definition of vitamin D deficiency and sufficiency, the health benefits of improving vitamin D status, and the required vitamin D intakes. Consequently, various societies and expert groups have released heterogeneous recommendations on the dosages for vitamin D supplementation. In this brief narrative review, we outline and discuss recent advances regarding the scientific evidence arguing for a daily vitamin D supplementation with 2000 international units (IU) (50 µg) of vitamin D3 to prevent and treat vitamin D deficiency. According to data from randomized controlled trials (RCTs), such a dose may improve some health outcomes and is sufficient to raise and maintain serum 25(OH)D concentrations above 50 nmol/L (20 ng/mL) and above 75 nmol/L (30 ng/mL) in >99% and >90% of the general adult population, respectively. According to large vitamin D RCTs, there are no significant safety concerns in supplementing such a dose for several years, even in individuals with an already sufficient vitamin D status at baseline. A daily vitamin D supplementation with 2000 IU (50 µg) may be considered a simple, effective, and safe dosage to prevent and treat vitamin D deficiency in the adult general population.

The Effect of Exercise on Quality of Life in Type 2 Diabetes: A Systematic Review and Meta-analysis

BACKGROUND

Exercise is a proven therapy for managing cardiometabolic risk factors in type 2 diabetes (T2D). However, its effects on patient-reported outcome measures such as quality of life (QoL) in people with T2D remain unclear. Consequently, the primary aim of this study was to determine the effect of regular exercise on QoL in adults with T2D. A secondary aim was to determine the effect of different exercise modalities on QoL. The third aim was to determine whether improvements in QoL were associated with improvements in gly'cated hemoglobin (A1C).

METHODS

Relevant databases were searched to May 2022. Eligible studies included randomized trials involving ≥2 wk of aerobic and/or resistance exercise and assessed QoL using a purpose-specific tool. Mean differences and 95% confidence intervals (CI) were calculated as standardized mean difference (SMD) or weighted mean difference. A regression analysis was undertaken to examine the interaction between change in QoL with change in A1C.

RESULTS

Of the 12,642 studies retrieved, 29 were included involving 2354 participants. Exercise improved QoL when compared with control (SMD, 0.384; 95% CI, 0.257 to 0.512; P < 0.001). Aerobic exercise, alone (SMD, 0.475; 95% CI, 0.295 to 0.655; P < 0.001) or in combination with resistance training (SMD, 0.363; 95% CI, 0.179 to 0.548; P < 0.001) improved QoL, whereas resistance training alone did not. Physical components of health-related QoL (HRQoL) improved with all exercise modalities, but mental components of HRQoL remained unchanged. Exercise improved A1C (mean difference, -0.509%; 95% CI, -0.806% to -0.212%; P = 0.001), and this change was associated with improvements in HRQoL ( β = -0.305, SE = 0.140, Z = -2.18, P = 0.030).

CONCLUSIONS

These results provide robust evidence that regular aerobic exercise alone or in combination with resistance training is effective for improving QoL in adults with T2D. Such improvements seem to be mediated by improvements in physical components of HRQoL and are associated with improved blood glucose control. Further studies should be undertaken to determine the relative importance of exercise duration, intensity, and frequency on patient-reported outcomes such as QoL.

Aerobic Exercise Ameliorates Myocardial Fibrosis via Affecting Vitamin D Receptor and Transforming Growth Factor-β1 Signaling in Vitamin D-Deficient Mice

Myocardial fibrosis is a pathological phenomenon associated with cardiovascular disease (CVD) that plays a crucial role in the development of heart diseases. Vitamin D deficiency can promote the development of CVD and exercise plays a role in the treatment of CVD. This study aimed to explore the effects of 12-week aerobic exercise training on myocardial fibrosis in vitamin D-deficient mice. A vitamin D-deficient mouse model was induced by a vitamin D-deficient (0 IU Vitamin D₃/kg) diet. Twenty-four C57BL/6J male mice were randomly divided into three groups: a control sedentary group (CONS, n = 8), a vitamin D-deficient sedentary group (VDDS, n = 8), and a vitamin D-deficient exercise group (VDDE, n = 8) which was aerobically trained for 12 weeks. The results showed that the serum 25-hydroxyvitamin D [25(OH)D] levels of the VDDS group were <50 nmol/L, which was significantly lower than that of the CONS group. Compared with the CONS group, the VDDS group showed cardiac dysfunction and significant fibrosis, together with lower vitamin D receptor (VDR) mRNA and protein expression levels, higher mRNA expression levels of profibrotic and inflammatory factors, and higher transforming growth factor-β1 (TGF-β1) and phospho-Smad2/3 (P-Smad2/3) protein expression levels. Serum 25(OH)D levels in the VDDE group were significantly higher than those in the VDDS group. Compared with the VDDS group, the VDDE group showed improved cardiac function and alleviated myocardial fibrosis. Meanwhile, the VDDE group had significantly higher VDR mRNA and protein expression levels; lower mRNA expression levels of profibrotic and inflammatory factors; and lower TGF-β1 and P-Smad2/3 protein expression levels. In conclusion, aerobic exercise training remains a promising intervention for treating myocardial fibrosis in vitamin D deficiency.

Does vitamin D supplementation improve bone health, body composition and physical performance beyond endurance exercise in patients with type 2 diabetes: A secondary analysis of randomized controlled trial

This study aimed to assess the effects of a 12-week vitamin D and endurance exercise intervention on bone health, body composition and physical performance among patients with type 2 diabetes. Totally, 61 patients were randomly assigned to vitamin D (VDG), exercise (EG), vitamin D and exercise intervention (VEG), and control (CG) groups. Bone health (bone mineral density, BMD; bone mineral content, BMC), body composition and physical performance were measured before and after the intervention. Dual energy X-ray absorptiometry was used to assess bone health and body composition. There were no additive effects of vitamin D beyond exercise were observed. Vitamin D supplementation had significant effects on maintaining bone health compared with their counterpart Total (BMC, EG + CG: 2,719.9 ± 70.0 vs. 2,670.1 ± 65.6; VDG + VEG: 2,610.9 ± 88.2 vs. 2,605.3 ± 84.8; trunk BMC, 870.2 ± 26.8 vs. 836.3 ± 23.7; 824.8 ± 29.5 vs. 822.1 ± 27.8; spine BMD, 1.15 ± 0.03 vs. 1.11 ± 0.02; 1.09 ± 0.03 vs. 1.09 ± 0.02) were observed. Exercise had a main effect on the reduction of total and trunk BF%. Patients in EG had a decreased BMC, while it was alleviated in VEG after intervention. Although no additive effect of vitamin D supplementation beyond exercise training, the supplementation had a potential effect on the prevention of bone loss induced by exercise only.

Associations of serum vitamin D and Fok I polymorphism of receptor gene with unexplained recurrent spontaneous abortion

Background: To investigate the associations of serum vitamin D and Fok I polymorphism of its receptor (VDR) with unexplained recurrent spontaneous abortion (URSA).

Methods: Ninety URSA patients and another 104 healthy pregnant women were selected as URSA and control groups, respectively. 25-Hydroxyvitamin D [25-(OH)D] level was detected by chemiluminescence. VDR gene Fok I polymorphism was analyzed by PCR, and the distribution of genotype frequency was calculated by Hardy-Weinberg equilibrium test. Association between Fok I polymorphism and susceptibility to URSA was investigated by logistic regression analysis.

Results: Gestational age, uterine height, waist circumference, 25-(OH)D level and proportions of Fok I FF and Ff genotypes were significantly lower in the URSA group (P<0.05). Compared with ff genotype, risk of URSA reduced for Ff and FF genotypes. Compared with allele f, risk of URSA was lower for allele F. 25-(OH)D level of ff genotype was significantly lower in the URSA group, which was lower than that of FF genotype (P<0.05). Compared with women with 25-(OH)D level >30 ng/mL and F allele (FF+Ff), the risk of URSA increased 2.45-, 2.43- and 5.34-fold for those with 25-(OH)D level >30 ng/mL and ff genotype, with 25-(OH)D level ≤30 ng/mL, and with ff genotype and 25-(OH)D level ≤30 ng/mL, respectively.

Conclusions: The 25-(OH)D level of the URSA group was significantly lower than that of normal pregnant women. Probably, VDR gene Fok I polymorphism is associated with URSA occurrence, and allele F decreases the risk. The risk of URSA dramatically increases in women with ff genotype and 25-(OH)D deficiency.

Exercise: A Possibly Effective Way to Improve Vitamin D Nutritional Status

Vitamin D deficiency has become a widespread public health problem owing to its potential adverse health effects. Generally, the nutritional status of vitamin D depends on sunlight exposure and dietary or supplementary intake. However, recent studies have found that exercise can influence circulating 25(OH)D levels; although, the results have been inconclusive. In this review, we focused on the effect of exercise on circulating vitamin D metabolites and their possible mechanisms. We found that endurance exercise can significantly increase serum 25(OH)D levels in vitamin D-deficient people but has no significant effect on vitamin D-sufficient people. This benefit has not been observed with resistance training. Only chronic endurance exercise training can significantly increase serum 1,25(OH)₂D, and the effect may be sex-dependent. Exercise may influence 25(OH)D levels in the circulation by regulating either the vitamin D metabolites stored in tissues or the utilization by target tissues. The effects of exercise on 25(OH)D levels in the circulation may be dependent on many factors, such as the vitamin D nutritional status, exercise type and intensity, and sex. Therefore, further research on the effects and mechanisms of exercise on vitamin D metabolites is required.

Physical Activity, Adiposity, and Serum Vitamin D Levels in Healthy Women: The Cooper Center Longitudinal Study

Background: Although physical inactivity, obesity, and low serum vitamin D [25-hydroxyvitamin D, 25(OH)D] are common among women, joint associations among these biomarkers are not well-described. Materials and Methods: A total of 7553 healthy women received a comprehensive examination (2006-2018), including self-reported physical activity (PA), body mass index (BMI), waist circumference (WC), waist:height ratio (W:HT), percent body fat (%Fat), and 25(OH)D. Participants were divided into four categories of PA based on current guidelines: <500 (not meeting guidelines), 500-1000 (meeting guidelines), 1001-2500 (>1-2.5 times guidelines), and >2500 (>2.5 times guidelines) metabolic equivalent-minutes/week (MET-Min/wk), and were also classified by clinical cut points for adiposity measures and 25(OH)D. We examined trends of 25(OH)D and adiposity exposures across PA categories and calculated odds ratios (ORs) of vitamin D deficiency across categories of each adiposity exposure. We examined joint associations among PA and adiposity with 25(OH)D. Results: A positive trend was observed for 25(OH)D across PA categories (p < 0.001). Compared with normal weight status, the odds for 25(OH)D deficiency were significantly higher for overweight women within adiposity exposures (p for all <0.001). When examining joint associations, 25(OH)D was higher across PA categories within each stratum of BMI, WC, W:HT, and %Fat (p trend <0.007 for all). When examining PA and BMI as continuous variables, OR for vitamin D deficiency were 0.95 (95% confidence interval [CI]: 0.93-0.96) per 250 MET-minutes/week increment in PA, and 1.20 (95% CI: 1.17-1.23) per 2 kg/m² increment in BMI. Conclusions: 25(OH)D levels are positively associated with PA and negatively associated with different measures of adiposity. Higher levels of PA attenuate the association between adiposity and 25(OH)D.

The Effect of High-intensity Interval Training vs Moderate-intensity Continuous Training on Liver Fat: A Systematic Review and Meta-Analysis

CONTEXT

Non-alcoholic fatty liver disease, characterized by excess fat accumulation in the liver, is considered the hepatic manifestation of metabolic syndrome. Recent findings have shown that high-intensity interval training (HIIT) can reduce liver fat but it is unclear whether this form of exercise is superior to traditional moderate-intensity continuous training (MICT).

OBJECTIVE

The aim of this systematic review was to determine the effect of HIIT vs MICT on liver fat in adults. A secondary aim was to investigate the interaction between total weekly exercise volume and exercise-related energy expenditure and change in liver fat.

METHODS

Relevant databases were searched up to December 2020 for randomized trials, comparing HIIT to control, MICT to control, or HIIT to MICT. Studies were excluded if they did not implement 2 or more weeks' intervention or assess liver fat using magnetic resonance-based techniques. Weighted mean differences and 95% CIs were calculated. Regression analyses were undertaken to determine the interaction between weekly exercise volume in minutes and kilocalories (kcal) with change in liver fat content.

RESULTS

Of the 28 268 studies screened, 19 were included involving 745 participants. HIIT and MICT both elicited moderate reductions in liver fat content when compared to control (HIIT: -2.85%, 95% CI, -4.86 to -0.84, P = .005, I2 = 0%, n = 114, low-certainty evidence; MICT: -3.14%, 95% CI, -4.45 to -1.82, P < .001, I2 = 5.2%, n = 533, moderate-certainty evidence). There was no difference between HIIT and MICT (-0.34%, 95% CI, -2.20 to 1.52, P = .721, I2 = 0%, n = 177, moderate-certainty evidence). Neither total exercise volume in minutes (β = .0002, SE = 0.0017, Z = 0.13, P = .89) nor exercise-related energy expenditure in kcal (β = .0003, SE = 0.0002, Z = 1.21, P = .23) were related to changes in liver fat content.

CONCLUSION

HIIT elicits comparable improvements in liver fat to MICT despite often requiring less energy and time commitment. Further studies should be undertaken to assess the relative importance of aerobic exercise prescription variables, such as intensity, on liver fat.

Combined effects of vitamin D supplementation and endurance exercise training on insulin resistance in newly diagnosed type 2 diabetes mellitus patients with vitamin D deficiency: study protocol for a randomized controlled trial

BACKGROUND

Although approximately 50% of Chinese with type 2 diabetes mellitus (T2DM) patients have vitamin D deficiency, studies regarding vitamin D supplementation on insulin resistance (IR) have mainly focused on non-Asians. Endurance exercise training (ET) enhances insulin-mediated glucose metabolism, which plays a critical role in T2DM prevention and control. However, the combined effects of vitamin D supplementation and ET on IR in T2DM patients are unclear. The objectives of this study is to investigate the synergistic effect of vitamin D supplementation combined with exercise training intervention on IR in T2DM patients.

METHODS AND ANALYSIS

We propose a 3-month randomized controlled trial among 60 T2DM patients aged 40-65, newly diagnosed with T2DM ≤ 1 year, and with stable HbA1c level (≤ 8.0%) in the past 3 months. The participants will be randomly allocated to the vitamin D group, vitamin D combined with exercise training group, exercise training group, and control group (CG) using a computer-generated random number sequence. At baseline, participants will undergo a medical review, anthropometric measurements, dual X-ray absorptiometry, a 75-g oral glucose tolerance test (OGTT), ankle-brachial index measurements, and physical fitness measurements and will complete related lifestyle questionnaires. Fasting blood lipid and glucose levels were also measured. In a 3-month intervention period, vitamin D intervention group will receive a dose of 1000 IU daily; exercise group will perform a 1-h endurance exercise 3 times per week (maximal heart rate, 60-80%), and the control group will receive apparently identical tablets. Additionally, all participants will be advised to maintain their normal diet and physical activities during the intervention. All measurements will be repeated at 3-month follow-up after the intervention with the primary outcome measure expressed as a change from baseline in insulin sensitivity and secretion. Secondary outcome measures will compare the changes in anthropometry, ankle-brachial index, and physical fitness factors (e.g., peak oxygen uptake, hand grip strength). Data will be managed and analyzed using the Statistical Package for the Social Sciences.

DISCUSSION

This is the first study to conduct a randomized trial to clearly determine the independent and combined effects of vitamin D supplementation and endurance exercise trial on IR in Chinese T2DM patients as measured by OGTT. The findings from the proposed study will not only provide new evidences that vitamin D supplementation plays an important role in IR management but also develop a simple and efficient method to improve IR-associated metabolic diseases for T2DM patients.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR1800015383 , Registered on 28 March 2018.

Effect of Exercise Training on 1,25(OH)2D Levels: The FIT-AGEING Randomized Controlled Trial

BACKGROUND

Vitamin D deficiency is currently endemic worldwide and is considered as an important factor in the development of several chronic conditions. Physical exercise has been postulated as an auspicious strategy to counteract age-related disorders preventing premature mortality. However, the effects of chronic exercise training on 1,25-dihydroxyvitamin D [1,25(OH)₂D] is unclear. This 12-week randomized controlled trial aimed to investigate the effects of different training modalities on 1,25(OH)₂D in healthy sedentary adults.

HYPOTHESIS

Exercise training will increase 1,25(OH)₂D in the study cohort.

STUDY DESIGN

Randomized controlled clinical trial.

LEVEL OF EVIDENCE

Level 1.

METHODS

A total of 89 healthy sedentary adults (53% women; 53.5 ± 4.9 years old) were enrolled in the FIT-AGEING study. The participants were randomized to (1) a control group (no exercise), (2) physical activity recommendation from the World Health Organization (PAR group), (3) high-intensity interval training (HIIT group), and (4) HIIT adding whole-body electromyostimulation training (HIIT + EMS). 1,25(OH)₂D plasma levels were measured using a DiaSorin Liaison immunochemiluminometric analyzer.

RESULTS

Compared with the control group, 1,25(OH)₂D increased in PAR (Δ = 10.99 ± 3.44 pg/mL; P = 0.01), HIIT (Δ = 11.63 ± 3.51 pg/mL; P = 0.009), and HIIT + EMS groups (Δ = 14.01 ± 3.59 pg/mL; P = 0.001) without statistical differences between them (all Ps > 0.1).

CONCLUSION

In summary, the results show that a 12-week exercise intervention produced an increment of 1,25(OH)₂D independently of age, sex, and exercise modality in healthy sedentary adults.

CLINICAL RELEVANCE

The implementation of physical exercise could be considered a strategy not only aiming to reverse the seasonal decrease of 1,25(OH)₂D in winter explained by low sunlight exposure but also for obtaining subsequent increases of this hormone even in these a priori adverse conditions.

Vitamin D Status and Its Correlation With Anthropometric and Biochemical Indicators of Cardiometabolic Risk in Serbian Underground Coal Miners in 2016

The status of vitamin D in underground working coal miners and its association with their cardiometabolic health is rarely studied. This study aimed to examine vitamin D (VitD) status in Serbian underground coal miners and to correlate it with anthropometric and laboratory indicators of cardiometabolic risk. Nutritional data (food frequency questionnaire, FFQ, and two times repeated 24 h recall), anthropometric data (including segmental analysis by bio-impedance analyzer TANITA BC-545N), arterial tension, and biochemical and hematological data of 103 coal miners (aged 22-63 years) were correlated with their late summer (early September) serum 25 (OH)D levels (measured by HPLC). 68.9% of the studied coal miners were overweight/obese, and 48.5% had metabolic syndrome. Their mean VitD nutritional intakes were low: 5.3 ± 3.8 μg/day (FFQ) and 4.9 ± 8 μg/day (24 h recalls), but their mean serum 25 (OH)D levels were surprisingly high (143.7 ± 41.4 nmol/L). Only 2.9% of the coal miners had 25(OH)D levels lower than 75 nmol/L (indicating an insufficient/deficient status), while 63.2% had values above 125 nmol/L (upper optimal limit), and even 10.7% had values above 200 nmol/L. There were no statistical differences in 25 (OH)D levels in the coal miners with or without metabolic syndrome (or overweight/obesity). Interestingly, 25(OH)D levels had significant positive correlations with body mass index (BMI), fat mass (FM), fat mass percentage (FM%), limbs FM%, serum triglycerides, GGT, AST, ALT, and ALT/AST ratio, and had significant negative correlations with serum HDL-cholesterol and age. All these correlations were lost after corrections for age, FM, FM%, and legs FM%. In Serbian coal miners, high levels of early September VitD levels were observed, indicating sufficient non-working-hour sun exposure during the summer period. Furthermore, the unexpected positive correlations of VitD levels with anthropometric and biochemical parameters indicative of obesity, metabolic syndrome, and fatty liver disease were found. More research is needed on the VitD status of coal miners (particularly in the winter period) and its relationship with their cardiometabolic status.

Fasting and Exercise Induce Changes in Serum Vitamin D Metabolites in Healthy Men

Background: Vitamin D plays pleiotropic roles in the body and hence, changes in its metabolism and distribution during starvation could play an important role in the adaptive response to famine. We aimed to identify the responses of some vitamin D metabolites to 8 d of fasting and exercise. Methods: A repeated-measures design was implemented, in which 14 male volunteers fasted for 8 d and performed an exercise test before and after fasting. Serum samples were collected on day 1 after night fasting and after 8 d of complete food restriction, before and 1 h and 3 h after exercise. Results: After 8 d of fasting, compared with baseline values, serum 24,25(OH)₂D₃ and 3-epi-25(OH)D₃ levels significantly increased; those of 25(OH)D₃ and 1,25(OH)₂D₃ were unaffected; and those of 25(OH)D₂ decreased. Exercise on the first day of fasting induced an increase in serum 3-epi-25(OH)D₃ levels, while exercise performed after 8 d of fasting induced an increase in 25(OH)D₃, 24,25(OH)₂D₃, 25(OH)D₂, and 3-epi-25(OH)D₃ levels. Conclusion: Increases in 24,25(OH)₂D₃ and 3-epi-25(OH)D₃ levels imply that fasting stimulates vitamin D metabolism. The effects of exercise on serum vitamin D metabolites, which are most pronounced after fasting and in subjects with serum 25(OH)D₃ above 25 ng/mL, support the notion that fasting and exercise augment vitamin D metabolism.

Concentrations of Ca, Mg, P, Prostaglandin E2 in Bones and Parathyroid Hormone; 1,25-dihydroxyvitamin D3; 17-β-estradiol; Testosterone and Somatotropin in Plasma of Aging Rats Subjected to Physical Training in Cold Water

Exposure to low temperatures can be considered a stressor, which when applied for a specific time can lead to adaptive reactions. In our study we hypothesized that cold, when applied to the entire body, may be a factor that positively modifies the aging process of bones by improving the mechanisms related to the body's mineral balance. Taking the above into account, the aim of the study was to determine the concentration of calcium (Ca), magnesium (Mg), and phosphorus (P) in bones, and to examine bone density and concentrations of the key hormones for bone metabolism, namely parathyroid hormone (PTH), somatotropin (GH), 1,25-dihydroxyvitamin D3, 17-β estradiol, testosterone (T) in plasma, and prostaglandin E2 (PGE2) in the bone of aging rats subjected to physical training in cold water. The animals in the experiment were subjected to a series of swimming sessions for nine weeks. Study group animals (male and female respectively) performed swimming training in cold water at 5 ± 2 °C and in water with thermal comfort temperature (36 ± 2 °C). Control animals were kept in a sedentary condition. Immersion in cold water affects bone mineral metabolism in aging rats by changing the concentration of Ca, Mg, and P in the bone, altering bone mineral density and the concentration of key hormones involved in the regulation of bone mineral metabolism. The effect of cold-water immersion may be gender-dependent. In females, it decreases Ca and Mg content in bones while increasing bone density and 17-β estradiol and 1,25-dihydroxyvitamin D3 levels, and with a longer perspective in aging animals may be positive not only for bone health but also other estrogen-dependent tissues. In males, cold water swimming decreased PTH and PGE2 which resulted in a decrease in phosphorus content in bones (with no effect on bone density), an increase in 1,25-dihydroxyvitamin D3, and increase in T and GH, and may have positive consequences especially in bones and muscle tissue for the prevention of elderly sarcopenia.

Vitamin D, sport and health: a still unresolved clinical issue

Vitamin D metabolites have a pleiotropic role in human physiology, both in static and dynamic conditions, and a lot of vitamin D-related biological effects could influence physical and sport performances in athletes. Probably due to different factors (e.g., drugs, doping, nutrition, ultraviolet B radiation exposure), in athletes a very high prevalence of vitamin D inadequacy (i.e., deficiency or insufficiency) has been observed. Vitamin D inadequacy in athletes could be associated with specific health risks and to alterations of functional capacities, potentially influencing the fine adjustment of physical performances during training and sport competitions. When risk factors for vitamin D inadequacy exist, a preventive vitamin D supplementation is indicated, and if a vitamin D inadequacy is diagnosed, its supplementation is recommended. Unfortunately, on these issues many concerns remain unresolved. Indeed, it is not clear if athletes should be classified as a special population at increased risk for vitamin D inadequacy; moreover, in comparison to the non-athletic population, it is still not clear if athletes should have different reference ranges and different optimal target levels for serum vitamin D, if they have additional health risks, and if they need different type of supplementations (doses) for prevention and/or replacement therapy. Moreover, in athletes also the abuse of vitamin D supplements for ergogenic purposes raise different ethical and safety concerns. In this review, the main physio-pathological, functional and clinical issues that relate vitamin D to the world of athletes are described.

Ultra-Marathon-Induced Increase in Serum Levels of Vitamin D Metabolites: A Double-Blind Randomized Controlled Trial

Purpose: While an increasing number of studies demonstrate the importance of vitamin D for athletic performance, the effects of any type of exercise on vitamin D metabolism are poorly characterized. We aimed to identify the responses of some vitamin D metabolites to ultra-marathon runs. Methods: A repeated-measures design was implemented, in which 27 amateur runners were assigned into two groups: those who received a single dose of vitamin D₃ (150,000 IU) 24 h before the start of the marathon (n = 13) and those (n = 14) who received a placebo. Blood samples were collected 24 h before, immediately after, and 24 h after the run. Results: In both groups of runners, serum 25(OH)D₃, 24,25(OH)₂D₃, and 3-epi-25(OH)D₃ levels significantly increased by 83%, 63%, and 182% after the ultra-marathon, respectively. The increase was most pronounced in the vitamin D group. Body mass and fat mass significantly decreased after the run in both groups. Conclusions: Ultra-marathon induces the mobilization of vitamin D into the blood. Furthermore, the 24,25(OH)₂D₃ and 3-epi-25(OH)D₃ increases imply that the exercise stimulates vitamin D metabolism.

The Effect of Aerobic and Resistance Training and Combined Exercise Modalities on Subcutaneous Abdominal Fat: A Systematic Review and Meta-analysis of Randomized Clinical Trials

Subcutaneous abdominal adipose tissue (SAT), is the largest fat depot and major provider of free fatty acids to the liver. Abdominal fat is indirectly (via increased levels of low-grade inflammation) correlated with many of the adverse health effects of obesity. Although exercise is one of the most prominent components of obesity management, its effects on SAT are still unclear. The aim of this study was to investigate the independent effects of aerobic training (AT) and resistance training (RT) modalities and combined exercise modalities on SAT in adults. PubMed, SCOPUS, and Google Scholar were searched to find relevant publications up to November 2018. The effect sizes were represented as weighted mean difference (WMD) and 95% CIs. Between-study heterogeneity was examined using the I2 test. Overall, 43 identified trials that enrolled 3552 subjects (2684 women) were included. After removal of outliers, combining effect sizes indicated a significant effect of AT (WMD: -13.05 cm2; 95% CI: -18.52, -7.57; P < 0.001), RT (WMD: -5.39 cm2; 95% CI: -9.66, -1.12; P = 0.01), and combined exercise training (CExT; WMD: -28.82 cm2; 95% CI: -30.83, -26.81; P < 0.001) on SAT relative to control groups. Pooled effect sizes demonstrated a significant effect of AT on SAT compared with a CExT group (WMD: 11.07 cm2; 95% CI: 1.81, 20.33; P = 0.01). However, when comparing the AT and RT groups, no significant difference was seen in SAT (WMD: -0.73 cm2; 95% CI: -4.50, 3.04; P = 0.70). Meta-analysis of relevant trials indicated that AT, RT, and CExT lead to SAT reduction. Aerobic exercise was shown to produce greater efficacy in decreasing SAT.

Effects of resistance training on serum 25(OH) D concentrations in young men: a randomized controlled trial

Background

Previous studies indicated that serum 25-hydroxyvitamin D [25(OH)D] concentrations are positively associated with physical activity levels independent of sun exposure. However, the effect of resistance training on serum 25(OH) D concentrations remains unclear. Thus, this study aimed to examine the effect of chronic resistance training on serum 25(OH) D concentrations and determine whether 25(OH) D concentration variations are influenced by body composition changes.

Methods

Eighteen young men aged 19–39 years were randomly divided into a 12-week resistance training group (RT, n = 9) and non-exercise control group (CON, n = 9). The trial was undertaken in Shanghai University of Sport in Shanghai, China. Randomization and allocation to trial group were carried out by a central computer system. Serum 25(OH) D and intact parathyroid hormone concentrations were measured using commercially available enzyme-linked immunosorbent assay kits. Body composition was measured by dual-energy X-ray absorptiometry.

Results

The average serum 25(OH) D concentrations were 26.6 nmol/L at baseline. After the 12-week intervention program, serum 25(OH) D concentrations significantly increased in both groups. Serum 25(OH) D concentrations at midpoint (6-week) increased significantly only in the CON group (P < 0.01). From training midpoint to endpoint, a significantly greater increase in serum 25(OH) D concentrations was noted in the RT group (P-interaction = 0.043); 25(OH) D concentration changes (end-pre) were negatively related to fat-free mass (mid-pre) (r = − 0.565, P = 0.015) and muscle mass (mid-pre) (r = − 0.554, P = 0.017).

Conclusions

There were no beneficial effects of the 12-week resistance training on serum 25(OH) D concentration in vitamin D deficient young men, and an indication that seasonal increase in serum 25(OH) D concentrations during the early phase of resistance training was transiently inhibited, which may partly be attributed to resistance training-induced muscle mass gain.

Trial registration

Chinese Clinical Trial Registry, ChiCTR2000030876. Registered 16 March 2020 - Retrospectively registered, http://www.chictr.org.cn/showproj.aspx?proj=50504.

The Effects of Concurrent Training Order on Satellite Cell-Related Markers, Body Composition, Muscular and Cardiorespiratory Fitness in Older Men with Sarcopenia

OBJECTIVES

Concurrent Training (CT) is described as a combination of resistance training (RT) and endurance training (ET) in a periodized program to maximize all aspects of physical performance. To date, effects of CT order on muscular and cardiorespiratory fitness adaptations are controversial. Owing to the age-related decrement in satellite cells (SC) which are critical for fiber repair, conservation, muscle hypertrophy as well as cardiorespiratory fitness, the present study examined the response of SC related markers to CT order in older sarcopenic men.

PARTICIPANTS

Thirty older men (age= 64.3 ± 3.5 years) were randomly assigned into one of 3 groups, ET followed by RT (E+R; n=10), RT followed by ET (R+E; n= 10) or a control (C; n=10).

INTERVENTION

The training protocol consisted of 3 exercise sessions per week for 8 weeks. Blood samples were obtained at baseline and 48 hours after the final training session.

RESULTS

Weight, skeletal muscle mass, lower and upper body power, maximal oxygen consumption (VO2max), Paired Box 7 (Pax7), and Myogenic factor 5 (Myf5) significantly increased, while were percent body fat significantly decreased following E+R and R+E compared to C. Importantly, the improvement in skeletal muscle mass, lower and upper body power, Myf5 and Pax7 in the E+R was significantly greater than the R+E group. Myogenin (Myog) and Paired Box 3 (Pax3) significantly increased (P < 0.01) in both training groups compared to no changes in C.

CONCLUSION

An 8-week CT intervention improves SC related markers, body composition and enhances power and VO2max in older sarcopenic participants, regardless of the order of RT and ET. However, performing ET before RT may be more effective at enhancing skeletal muscle mass, Myf5 and Pax7, in addition to both lower and upper body power. While both CT programs produced notable physiological and performance benefits, performing ET before RT during CT may provide the greatest therapeutic benefits for aging individuals.

Early Rehabilitation Program and Vitamin D Supplementation Improves Sensitivity of Balance and the Postural Control in Patients after Posterior Lumbar Interbody Fusion: A Randomized Trial

BACKGROUND

The introduction of early rehabilitation exercise is the foundation of treatment post-Posterior lumbar interbody fusion (PLIF) surgery, and the search for additional sources of reinforcement physiotherapy seems to be very important.

METHODS

The patients were randomly divided into the vitamin D3 (n = 15; D3) supplemented group and received 3200 IU per day for five weeks before surgery and the placebo group (n = 18; Pl) received vegetable oil during the same time. The patients began the supervisor rehabilitation program four weeks after surgery.

RESULTS

The limits of stability (LOS) were significantly improved in the D3 group after 5 and 14 weeks (p < 0.05), while in the Pl group, progress was only observed after 14 weeks (p < 0.05). The LOS were also higher in the D3 group than in the Pl group after five weeks of supervised rehabilitation (p < 0.05). In the postural stability (PST) test, significant progress was observed in the D3 group after 14 weeks (p < 0.02). In addition, neither rehabilitation nor supplementation had significant effects on the risk of falls (RFT).

CONCLUSIONS

Vitamin D supplementation seems to ameliorate the effects of an early postoperative rehabilitation program implemented four weeks after posterior lumbar interbody fusion. Early physiotherapy treatment after PLIF surgery combined with vitamin D supplementation appears to be a very important combination with regard to the patients' recovery process.

Mobilising vitamin D from adipose tissue: The potential impact of exercise

Vitamin D is lipophilic and accumulates substantially in adipose tissue. Even without supplementation, the amount of vitamin D in the adipose of a typical adult is equivalent to several months of the daily reference nutrient intake (RNI). Paradoxically, despite the large amounts of vitamin D located in adipose tissue, individuals with obesity are often vitamin D deficient according to consensus measures of vitamin D status (serum 25-hydroxyvitamin D concentrations). Thus, it appears that vitamin D can become 'trapped' in adipose tissue, potentially due to insufficient lipolytic stimulation and/or due to tissue dysfunction/adaptation resulting from adipose expansion. Emerging evidence suggests that exercise may mobilise vitamin D from adipose (even in the absence of weight loss). If exercise helps to mobilise vitamin D from adipose tissue, then this could have important ramifications for practitioners and policymakers regarding the management of low circulating levels of vitamin D, as well as chronically low levels of physical activity, obesity and associated health conditions. This perspective led us to design a study to examine the impact of exercise on vitamin D status, vitamin D turnover and adipose tissue vitamin D content (the VitaDEx project). The VitaDEx project will determine whether increasing physical activity (via exercise) represents a potentially useful strategy to mobilise vitamin D from adipose tissue.

The effect of an exercise program in pregnancy on vitamin D status among healthy, pregnant Norwegian women: a randomized controlled trial

BACKGROUND

Vitamin D insufficiency is common in pregnant women worldwide. Regular prenatal exercise is considered beneficial for maternal and fetal health. There is a knowledge gap regarding the impact of prenatal exercise on maternal vitamin D levels. The objective of this study was to investigate whether a prenatal exercise program influenced serum levels of total, free and bioavailable 25-hydroxyvitamin D (25(OH)D) and related parameters. This is a post hoc analysis of a randomized controlled trial with gestational diabetes as the primary outcome.

METHODS

Healthy, pregnant women from two Norwegian cities (Trondheim and Stavanger) were randomly assigned to a 12-week moderate-intensity exercise program (Borg perceived rating scale 13-14) or standard prenatal care. The intervention group (n = 429) underwent exercise at least three times weekly; one supervised group training and two home based sessions. The controls (n = 426) received standard prenatal care, and exercising was not denied. Training diaries and group training was used to promote compliance and evaluate adherence. Serum levels of 25(OH)D, parathyroid hormone, calcium, phosphate, magnesium and vitamin D-binding protein were measured before (18-22 weeks' gestation) and after the intervention (32-36 weeks' gestation). Free and bioavailable 25(OH)D concentrations were calculated. Regression analysis of covariance (ANCOVA) was applied to assess the effect of the training regime on each substance with pre-intervention levels as covariates. In a second model, we also adjusted for study site and sampling month. Intention-to-treat principle was used.

RESULTS

A total of 724 women completed the study. No between-group difference in serum 25(OH)D and related parameters was identified by ANCOVA using baseline serum levels as covariates. The second model revealed a between-group difference in levels of 25(OH)D (1.9, 95% CI 0.0 to 3.8 nmol/L; p = 0.048), free 25(OH)D (0.55, 95% CI 0.10 to 0.99 pmol/L; p = 0.017) and bioavailable 25(OH)D (0.15 95% CI 0.01 to 0.29 nmol/L; p = 0.036). No serious adverse events related to regular exercise were seen.

CONCLUSION

This study, a post hoc analysis, indicates that exercise may affect vitamin D status positively, and emphasizes that women with uncomplicated pregnancies should be encouraged to perform regular exercise.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00476567 , registered May 22, 2007.

Serum 25-Hydroxyvitamin D Concentrations Are Inversely Correlated with Hepatic Lipid Content in Male Collegiate Football Athletes

Lower serum 25-hydroxyvitamin D (25(OH)D) concentrations are associated with more weight and fat mass gain in adults in the general population, but it is unknown whether this is the case in collegiate football athletes with greater body weight. This study aimed to investigate associations of serum 25(OH)D concentrations with body fat and ectopic fat accumulation, and to determine which fat indicators are closely related to serum 25(OH)D in male collegiate football athletes. Thirty-four collegiate athletes aged 21 years were recruited. Serum 25(OH)D concentrations and the levels of visceral fat area (VFA), vastus lateralis intramyocellular lipid (IMCL), extramyocellular lipid (EMCL), and intrahepatic lipid (IHCL) were measured. Serum 25(OH)D concentrations were negatively associated with the IHCL values (r = −0.372, p = 0.030), and the relationship remained after adjustment for several factors (r = −0.378, p = 0.047). Additionally, multiple stepwise regression analysis of IHCL content as the dependent variable indicated that 25(OH)D concentrations were a stronger predictor of IHCL content (β = −0.363, p = 0.030) than % body fat and VO₂peak_FFM. Higher serum 25(OH)D concentrations are more closely related to lower IHCL content rather than any other fat indicators, suggesting that increasing serum 25(OH)D concentrations may have some effect that inhibits lipid accumulation in hepatic tissue, especially in heavy athletes.