Single bout of exercise triggers the increase of vitamin D blood concentration in adolescent trained boys: a pilot study

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.

Seasonal changes in free 25-(OH)D and vitamin D metabolite ratios and their relationship with psychophysical stress markers in male professional football players

Introduction: Novel markers of vitamin D status are currently being investigated, including free 25-(OH)D (25-(OH)DF) and the vitamin D metabolite ratio (24,25-(OH)2D3:25-(OH)D3; VMR). The VMR may provide additional functional information on vitamin D metabolism in athletes. Therefore, the main objective of the current study was to evaluate 25-(OH)DF, bioavailable 25-(OH)D (25-(OH)DB), VMR, and psychophysical stress markers during different training periods over a half-season. The second aim was to assess the association between vitamin D binding protein (VDBP), total and free 25-(OH)D, VMRs, and psychophysical stress markers in professional football players. Moreover, we examined the relationship between 25-(OH)D3 and vitamin D metabolites (24,25-(OH)2D3, 3-epi-25-(OH)D3) to determine if training loads in different training periods influenced the vitamin D metabolome. Methods: Twenty professional football players were tested at six different time points across half a year (V1-June; V2-July; V3-August; V4-October; V5-December; V6-January). Results: Analyses indicated a significant seasonal rhythm for VDBP, and total 25-(OH)D (25-(OH)DT), 25-(OH)DB, 24,25-(OH)2D3, 3-epi-25-(OH)D3, 25-(OH)D3:24,25-(OH)2D3, and 24,25-(OH)2D3:25-(OH)D3 VMRs throughout the training period. No correlation was detected between 25-(OH)DT, 25-(OH)DB, 25-(OH)DF, vitamin D metabolites, VMRs, VDBP, and ferritin, liver enzymes (aspartate transaminase [AST] and alanine transaminase [ALT]), creatine kinase (CK), cortisol, testosterone, and testosterone-to-cortisol ratio (T/C) in each period (V1-V6). However, there was a strong statistically significant correlation between 25-(OH)D3 and 24,25-(OH)D3 in each training period. Conclusion: In conclusion, a seasonal rhythm was present for VDBP, 25-(OH)DT, 25-(OH)DB, vitamin D metabolites (24,25-(OH)2D3, 3-epi-25-(OH)D3), and VMRs (25-(OH)D3:24,25-(OH)2D3, 25-(OH)D3:3-epi-25-(OH)D3). However, no rhythm was detected for 25-(OH)DF and markers of psychophysical stress (ferritin, liver enzymes, CK, testosterone, cortisol, and T/C ratio). Moreover, the relationships between free and total 25-(OH)D with psychophysical stress markers did not demonstrate the superiority of free over total measurements. Furthermore, training loads in different training periods did not affect resting vitamin D metabolite concentrations in football players.

The Role of Vitamin D in Skeletal Muscle Repair and Regeneration in Animal Models and Humans: A Systematic Review

Vitamin D deficiency, prevalent worldwide, is linked to muscle weakness, sarcopenia, and falls. Muscle regeneration is a vital process that allows for skeletal muscle tissue maintenance and repair after injury. PubMed and Web of Science were used to search for studies published prior to May 2023. We assessed eligible studies that discussed the relationship between vitamin D, muscle regeneration in this review. Overall, the literature reports strong associations between vitamin D and skeletal myocyte size, and muscle regeneration. In vitro studies in skeletal muscle cells derived from mice and humans showed vitamin D played a role in regulating myoblast growth, size, and gene expression. Animal studies, primarily in mice, demonstrate vitamin D's positive effects on skeletal muscle function, such as improved grip strength and endurance. These studies encompass vitamin D diet research, genetically modified models, and disease-related mouse models. Relatively few studies looked at muscle function after injury, but these also support a role for vitamin D in muscle recovery. The human studies have also reported that vitamin D deficiency decreases muscle grip strength and gait speed, especially in the elderly population. Finally, human studies reported the benefits of vitamin D supplementation and achieving optimal serum vitamin D levels in muscle recovery after eccentric exercise and surgery. However, there were no benefits in rotator cuff injury studies, suggesting that repair mechanisms for muscle/ligament tears may be less reliant on vitamin D. In summary, vitamin D plays a crucial role in skeletal muscle function, structural integrity, and regeneration, potentially offering therapeutic benefits to patients with musculoskeletal diseases and in post-operative recovery.

Targeting neuroendocrine abnormalities in Parkinson's disease with exercise

Parkinson's Disease (PD) is a prevalent and complex age-related neurodegenerative condition for which there are no disease-modifying treatments currently available. The pathophysiological process underlying PD remains incompletely understood but increasing evidence points to multiple system dysfunction. Interestingly, the past decade has produced evidence that exercise not only reduces signs and symptoms of PD but is also potentially neuroprotective. Characterizing the mechanistic pathways that are triggered by exercise and lead to positive outcomes will improve understanding of how to counter disease progression and symptomatology. In this review, we highlight how exercise regulates the neuroendocrine system, whose primary role is to respond to stress, maintain homeostasis and improve resilience to aging. We focus on a group of hormones - cortisol, melatonin, insulin, klotho, and vitamin D - that have been shown to associate with various non-motor symptoms of PD, such as mood, cognition, and sleep/circadian rhythm disorder. These hormones may represent important biomarkers to track in clinical trials evaluating effects of exercise in PD with the aim of providing evidence that patients can exert some behavioral-induced control over their disease.

Treatment of vitamin D deficiency in children

INTRODUCTION

Vitamin D deficiency affects from 10% to 50% in various pediatric population groups and causes life-threatening hypocalcemia in infants, crippling rickets in infants and children, and increased risk of subsequent adult metabolic and neurologic problems.

AREAS COVERED

An English language literature search of PubMed was performed since 1940 as were the authors' personal literature collections. References identified in the reviewed literature are considered.

DIAGNOSIS

The diagnosis of vitamin D deficiency is based on serum 25-hydroxyvitamin D levels. Clinical features of rickets include bone deformities and elevated alkaline phosphatase. Most children and adolescents who are biochemically vitamin D deficient do not have specific symptoms or signs of deficiency.

PREVENTION

Prevention of vitamin D deficiency is via exposure to sunshine, food and beverage fortification, and dietary supplementation.

TREATMENT

Effective treatment of vitamin D deficiency is via oral or injectable administration of vitamin D. Dosing and duration of vitamin D therapy have been described for healthy children and for children with underlying medical conditions, but recommendations vary.

EXPERT OPINION

Further investigation is needed to determine long-term non-skeletal effects of childhood vitamin D deficiency, benefits of supplementation in asymptomatic individuals with biochemical vitamin D deficiency, and appropriate screening for vitamin D deficiency in asymptomatic children and adolescents.

Metabolism of vitamin D is not affected by sport activity

BACKGROUND

Higher levels of physical activity are related to higher 25-(OH)D levels. Total 25-(OH)D (25-(OH)DT) are routinely used in clinical practice to assess vitamin D, however novel biomarkers are currently being investigated as free 25-(OH)D (25-(OH)DF) or vitamin D metabolite ratios (VMRs). The primary aim of our study was to assess 25-(OH)DF, vitamin D metabolites and VMRs in inactive men and athletes. A secondary aim was to check whether regular physical activity influence on vitamin D metabolome. A tertiary aim was to determine the relationship between 25-(OH)DT, 25-(OH)DF, vitamin D binding protein (VDBP), vitamin D metabolites and VMRs in this cohort.

METHODS

A total of 69 participants (27 inactive men, 18 indoor and 24 outdoor athletes) participated in the study. Vitamin D metabolites (25-(OH)DT, 24,25-(OH)2D3, 3-epi-25-(OH)D3, and 1,25-(OH)2D) were assessed using LC-MS/MS. The 25-(OH)DF concentration was calculated based on serum albumin and VDBP levels.

RESULTS

There were no differences in vitamin D metabolites and VMRs between inactive men and between the two groups of athletes. We showed a strong relationship between 25-(OH)DT, 25-(OH)DF and 24,25-(OH)D3, 3-epi-25(OH)D3, 24,25-(OH)2D3:25-(OH)D3 VMR in each group. Analysis showed that 25-(OH)DT, 25-(OH)DF inversely associated with 25-(OH)D3:24,25-(OH)2D3, 25-(OH)D3:3-epi-25-(OH)D3, 1,25-(OH)2D:24,25-(OH)2D3 ratios in inactive men and athletes (indoor and outdoor).

CONCLUSIONS

On the basis of our results, we concluded that regular long-term physical activity has no effect on the concentration of vitamin D metabolites at rest. Furthermore, free vitamin D does not correlate more strongly with vitamin D metabolites and VMRs compared to total.

Effects of Probiotics and Vitamin D3 Supplementation on Sports Performance Markers in Male Mixed Martial Arts Athletes: A Randomized Trial

BACKGROUND

Strategies targeted at the intestine microbiome seem to be beneficial for professional athletes. The gut-muscle axis is associated with the inflammatory state, glucose metabolism, mitochondrial function, and central nervous system health. All these mechanisms may affect maximal oxygen uptake, muscle strength, and training adaptation. Moreover, the positive effect of certain bacterial strains may be enhanced by vitamin D. Thus, this study aimed to assess and compare the level of selected markers of sports performance of mixed martial arts (MMA) athletes supplemented with vitamin D₃ or probiotics combined with vitamin D₃.

METHODS

A 4-week randomized double-blind placebo-controlled clinical trial was conducted with 23 MMA male athletes assigned to the vitamin D₃ group (Vit D; n = 12) or probiotics + vitamin D₃ group (PRO + VitD; n = 11). Repeated measures of the creatine kinase level, lactate utilization ratio, and anaerobic performance were conducted.

RESULTS

After 4 weeks of supplementation, we found lower lactate concentrations 60 min after the acute sprint interval in the PRO + VitD group when compared to the Vit D group (4.73 ± 1.62 and 5.88 ± 1.55 mmol/L; p < 0.05). In addition, the intervention improved the total work (232.00 ± 14.06 and 240.72 ± 13.38 J kg^-1; p < 0.05), and mean power following the anaerobic exercise protocol (7.73 ± 0.47 and 8.02 ± 0.45 W kg^-1; p < 0.05) only in the PRO + VitD group. Moreover, there was an improvement in the lactate utilization ratio in the PRO + VitD group compared with the Vit D group as shown by the percentage of T60/T3 ratio (73.6 ± 6.9 and 65.1 ± 9.9%, respectively; p < 0.05). We also observed elevated serum 25(OH)D₃ concentrations after acute sprint interval exercise in both groups, however, there were no significant differences between the groups.

CONCLUSION

Four weeks of combined probiotic and vitamin D₃ supplementation enhanced lactate utilization and beneficially affected anaerobic performance in MMA athletes.

More than a Feeling: Dermatological Changes Impacted by Spaceflight

Spaceflight poses a unique set of challenges to humans and the hostile Spaceflight environment can induce a wide range of increased health risks, including dermatological issues. The biology driving the frequency of skin issues in astronauts is currently not well understood. To address this issue, we used a systems biology approach utilizing NASA's Open Science Data Repository (OSDR) on spaceflown murine transcriptomic datasets focused on the skin, biomedical profiles from fifty NASA astronauts, and confirmation via transcriptomic data from JAXA astronauts, the NASA Twins Study, and the first civilian commercial mission, Inspiration4. Key biological changes related to skin health, DNA damage & repair, and mitochondrial dysregulation were determined to be involved with skin health risks during Spaceflight. Additionally, a machine learning model was utilized to determine key genes driving Spaceflight response in the skin. These results can be used for determining potential countermeasures to mitigate Spaceflight damage to the skin.

Vitamin D Inadequacy Affects Skeletal Muscle Index and Physical Performance in Lumbar Disc Degeneration

Lumbar disc degeneration (LDD) is one of the fundamental causes of low back pain. The aims of this study were to determine serum 25-hydroxyvitamin D (25(OH)D) levels and physical performance and to investigate the relationship between serum vitamin D levels, muscle strength and physical activity in elderly patients with LDD. The participants were 200 LDD patients, including 155 females and 45 males aged 60 years and over. Data on body mass index and body composition were collected. Serum 25(OH)D and parathyroid hormone levels were measured. Serum 25(OH)D was classified into the insufficiency group: <30 ng/mL and the sufficiency group: ≥30 ng/mL. Muscle strength was assessed by grip strength, and physical performance (short physical performance battery) was evaluated by the balance test, chair stand test, gait speed, and Timed Up and Go (TUG) test. Serum 25(OH)D levels in LDD patients with vitamin D insufficiency were significantly lower than in those with vitamin D sufficiency (p < 0.0001). LDD patients with vitamin D insufficiency had a prolonged time in physical performance on gait speed (p = 0.008), chair stand test (p = 0.013), and TUG test (p = 0.014) compared to those with vitamin D sufficiency. Additionally, we found that serum 25(OH)D levels were significantly correlated with gait speed (r = -0.153, p = 0.03) and TUG test (r = -0.168, p = 0.017) in LDD patients. No significant associations with serum 25(OH)D status were observed for grip strength and balance tests among patients. These findings demonstrate that higher serum 25(OH)D levels are associated with better physical performance in LDD patients.

Serum fat-soluble vitamins and the menstrual cycle in women of childbearing age

Evidence suggests that fat-soluble vitamins are involved in reproduction, but their association with the menstrual cycle, the proxy of female fecundity, remains largely unexplored in women of childbearing age. Serum fat-soluble vitamin levels were measured by HPLC-MS/MS and menstrual cycle data were acquired from 3123 women of reproductive age in Nanjing, China, using standard questionnaires. Irregular and long menstrual cycles occurred in 725 (23.2%) and 604 (19.3%) participants, respectively. Participants with higher levels of vitamins A and K had increased odds of irregular menstrual cycles (vitamin A: OR = 1.39 (95% CI: 1.12, 1.74); vitamin K: OR = 1.41 (95% CI: 1.13, 1.76)) and long menstrual cycles (vitamin A: OR = 1.34 (95% CI: 1.06, 1.69); vitamin K: OR = 1.27 (95% CI: 1.00, 1.61)), and the relationship showed a linear dose-response pattern (P-overall < 0.05, P-nonlinearity > 0.05). Vitamin A was positively associated with the average menstrual cycle length (β: 1.83, 95% CI: 0.28, 3.39). Vitamins A and K were interacted in their associations with irregular menstrual cycles and long cycles. In sensitivity analysis with further exclusion of participants with abnormal thyroid function or a history of polycystic ovary syndrome (PCOS), the association of vitamins A and K with the menstrual cycle remained robust. This study indicates that higher serum vitamin A and K levels in women of childbearing age are significantly associated with higher odds of irregular and long menstrual cycles with a linear dose-response curve. Further investigations are warranted to determine the appropriate fat-soluble vitamin levels for women of childbearing age.

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.

There is more to life than serum vitamin D: a lesson from the past

This commentary revisits a paper from Clinical Science in 1972 entitled “The distribution and storage of vitamin D and its metabolites in human tissues” by Barbara Mawer, Bill Stanbury and colleagues. The paper continues to be well cited 50 years later, in part because the study it describes – which includes the use of human autopsy tissue – would be difficult to replicate today. However, the paper also has resonance today because the focus of the study – what is the fate of vitamin D in the body? – is still not clear. This commentary discusses why the Mawer et al. study was a major advance when published and why there is still much to be learned from this paper half a century later.