Effect of vitamin D supplementation in chronic widespread pain: a systematic review and meta-analysis

Systemic Factors Affecting Pain Management in Dentistry

There are several factors that affect a patient's experience of pain. These include both local and systemic factors. The systemic factors that affect patients' dental and orofacial pain experience include, but not limited to, hormonal, nutritional, systemic infections, neurodegenerative, and autoimmune, among others. Comprehensive medical history is essential to delineate any possible systemic factors affecting pain experience. A thorough review of systems should form the foundation, since multiple factors can affect the prognosis of pain management. This would facilitate early recognition and trigger prompt referrals to the appropriate medical professionals. This helps to reduce the health care burden.

Serum Vitamin D and Chronic Musculoskeletal Pain: A Cross-Sectional Study of 349,221 Adults in the UK

Insufficient and deficient vitamin D may be associated with chronic musculoskeletal pain, but study findings are conflicting, and few account for important confounding factors. This cross-sectional study explored the association between serum vitamin D status and chronic musculoskeletal pain in various body sites, adjusting for a wide range and a number of potential confounding factors. Data collected at the baseline assessments of 349,221 UK Biobank participants between 2006 and 2010 were analyzed. Serum 25-hydroxyvitamin D was measured and categorized as <25.0 nmol/L (severe deficiency), 25.0 to 49.9 nmol/L (deficiency), 50.0 to 74.9 nmol/L (insufficiency), and ≥75.0 nmol/L (sufficiency). The outcome was self-reported chronic musculoskeletal pain at any site, neck/shoulder, back, hip, knee, or widespread pain that interfered with usual activities. Potential confounders were identified using directed acyclic graphs and included sociodemographic, lifestyle, psychological factors, and medical comorbidities. Simple models adjusted for age and sex showed significant associations between suboptimal vitamin D status and chronic pain across all sites (odds ratios [ORs] ranged 1.07-2.85). These associations were weakened or became insignificant after accounting for all confounding factors (ORs ≤ 1.01) for chronic regional musculoskeletal pain. Severe vitamin D deficiency remained a significant and positive association with chronic widespread pain after adjusting for all confounding factors (OR [95% confidence interval]: 1.26 [1.07, 1.49]). This study suggests that, while vitamin D status is not a key independent determinant of chronic regional musculoskeletal pain, severe vitamin D deficiency may be associated with chronic widespread pain. PERSPECTIVE: After accounting for various confounders, vitamin D deficiency was not associated with regional musculoskeletal pain. However, the relationship between chronic widespread pain severe vitamin D deficiency remained after confounder adjustment. Use of vitamin D supplements in individuals with chronic widespread pain and severe vitamin D deficiency warrants further exploration.

Safety and efficacy of monthly high-dose vitamin D3 supplementation in children and adolescents with sickle cell disease

Little is known about the impact of vitamin D supplementation on hand grip strength (HGS) and health-related quality of life (HRQoL) in children and adolescents with sickle cell disease (SCD). We aimed to evaluate the safety and efficacy of monthly high-dose vitamin D3 supplementation and its implications on bone mineral density (BMD), HGS, and HRQoL in patients with SCD and healthy controls. The study included 42 children with SCD and 42 healthy matched controls. The study participants were supplemented with high-dose monthly oral vitamin D3. Changes in the serum level of 25(OH) vitamin D3, maximum HGS, and BMD from baseline to 6 months were assessed, and the HRQoL questionnaire and Childhood Health Assessment Questionnaire (CHAQ) were used to evaluate the functional capacity. At baseline, SCD subjects had poorer growth status indicated by negative Z scores. Suboptimal BMD was detected by significantly lower Z score, and lower HGS and worse HRQL parameters were found compared to the controls (P < 0.001). Median 25(OH) vitamin D3 was significantly lower in SCD patients compared to controls (16.5 vs. 28 ng/mL, respectively (P < 0.001)). After 6 months of vitamin D supplementation, there was significant improvement in the DEXA Z-score (P < 0.001), limitation of physical health (P = 0.02), pain scores (P < 0.001), and CHAQ grades (P = 0.01) in SCD patients. A significant improvement in HGS (P < 0.001 and P = 0.005) as well as the CHAQ score (P < 0.001 and P = 0.003) was detected in the SCD group and controls, respectively. There were no reported clinical adverse events (AEs) or new concomitant medications (CMs) during the study duration, and safe levels of Ca and 25 (OH) D3 were observed at 3 and 6 months for both groups. There was a significant positive correlation between HGS and total physical score (r = 0.831, P < 0.001) and a negative correlation with CHAQ score (r =  - 0.685, P < 0.001). We also detected a significant positive correlation between vitamin D levels at 6 months and HGS (r = 0.584, P < 0.001), pain score (r = 0.446, P < 0.001), and a negative correlation with CHAQ score (r =  - 0.399, P < 0.001).   Conclusion: Monthly oral high-dose vitamin D supplementation was safe and effective in improving vitamin D levels, HGS, and HRQoL in SCD children and healthy subjects, and BMD scores in SCD patients. Further randomized controlled trials are warranted to assess an optimal dosing strategy and to investigate the impact on clinically significant outcomes in children and adolescents with SCD and their healthy counterparts.   Trial registration: ClinicalTrials.gov , identifier NCT06274203, date of registration: 23/02/2024, retrospectively registered. What is known: • Several studies have reported a high prevalence of vitamin D deficiency and suboptimal bone mineral density (BMD) in sickle cell disease (SCD) patients. • Musculoskeletal dysfunction is reported in SCD patients with a negative impact on physical activity and health-related quality of life (HRQL). • Little is known regarding the impact of vitamin D3 supplementation in children and adolescents with SCD. What is new: • We found that monthly oral high-dose vitamin D3 supplementation was safe, tolerated, and effective in improving serum vitamin D levels, HGS, BMD scores, and HRQL in SCD patients.

Vitamin D and tension-type headache: causal association or epiphenomenon?

Background-Purpose: Low serum vitamin D (VD) has been already associated with a series of highly prevalent pain-related conditions, including fibromyalgia, migraine and chronic widespread pain. Considering the potential interplay between VD and pain signalling pathways, the association of VD with tension-type headache (TTH) was reviewed.

Methods: A multifaceted narrative approach assessing the relationship of serum VD with TTH and TTH parameters, as well as the efficacy of VD supplementation for the prevention of TTH, was fostered. MEDLINE, CENTRAL and EMBASE were comprehensively searched for this purpose, while Google Scholar was also explored according to a structured approach. ClinicalTrials.gov and European Union Clinical Trials Register were explored for ongoing prevention trials.

Results: Although available evidence was suggestive of an association between VD and TTH, mainly of the chronic type, the causal nature of the association remains to be determined. Considering the lack of longitudinal evidence, this relationship could arguably reflect behavioural patterns of headache sufferers. On the other hand, evidence principally originated from tertiary clinical settings (severe comorbidity burden) and researchers tend to report a concomitant association of both entities with generalized musculoskeletal compromise. In this context, the association between TTH and VD may represent nothing more than a secondary by-product of the simultaneous relationship of other comorbid diseases-conditions with both TTH and low serum VD. Regarding its efficacious properties, only one ongoing trial specifically designed to explore the efficacy of VD in chronic TTH in adults was retrieved.

Conclusions: There is no evidenced based indication for VD supplementation in TTH.

Online Questionnaire with Fibromyalgia Patients Shows Negative Correlations between Disease Severity and Adherence to Mediterranean Diet

Fibromyalgia (FM) is a multidimensional disorder in which intense chronic pain is accompanied by a variety of psychophysical symptoms that impose a burden on the patients' quality of life. Despite the efforts and the recent advancement in research, FM pathogenesis and effective treatment remain unknown. Recently, the possible role of dietary patterns and/or components has been gaining attention. The current study aimed to investigate a potential correlation between adherence to the Mediterranean diet (MedDiet) and FM severity in a sample of Italian FM patients. An online survey was designed, composed of customized questions and validated questionnaires with the aim of investigating the intensity and type of pain, the presence of other psychophysical symptoms, the overall impact of FM, general food and lifestyle habits, and adherence to the MedDiet. The collected responses were analyzed for descriptive statistics, linear regression, and propensity score analyses. The results show that, despite considerable use of pharmaceuticals and supplements, FM participants suffered from a high-severity grade disease. However, those with good adherence to the MedDiet experienced a lower pain intensity and overall FM impact. A propensity score analysis indicates a positive influence of the MedDiet against FM severity, thus unveiling the need for well-designed intervention studies to evaluate the therapeutic potential of different dietary patterns.

Environmental factors and their impact on chronic pain development and maintenance

It is more than recognized and accepted that the environment affects the physiological responses of all living things, from bacteria to superior vertebrates, constituting an important factor in the evolution of all species. Environmental influences range from natural processes such as sunlight, seasons of the year, and rest to complex processes like stress and other mood disorders, infections, and air pollution, being all of them influenced by how each creature deals with them. In this chapter, it will be discussed how some of the environmental elements affect directly or indirectly neuropathic pain, a type of chronic pain caused by a lesion or disease of the somatosensory nervous system. For that, it was considered the edge of knowledge in translational research, thus including data from human and experimental animals as well as the applicability of such findings.

Psychological Outcomes and Quality of Life of Fibromyalgia Patients with Vitamin D Supplementation-A Meta-Analysis

The efficacy of current pharmaceutical treatments for fibromyalgia are limited. Vitamin D has shown promise in relieving pain. However, there is a lack of comprehensive analysis of psychological outcomes with vitamin D supplementation in fibromyalgia. This study aimed to investigate the impact of vitamin D supplementation on psychological outcomes and quality of life in fibromyalgia patients, given the unmet clinical need for effective treatment options. A meta-analysis of randomized controlled trials comparing vitamin D to placebo and prospective studies examining changes before and after vitamin D supplementation for patients with fibromyalgia was conducted to evaluate the effects of vitamin D on psychological outcomes, quality of life, and pain scores in patients with fibromyalgia. Databases were searched for relevant articles published from earliest available date to October 31, 2022. (PROSPERO number, CRD42022369889). We included 8 trials with a total of 694 participants and found that vitamin D supplementation had significant positive effects on physical function (standard mean differences (SMD) = 0.44, 95% CI = [0.10, 0.77 ]), role limitations due to emotional health (SMD = 0.57, 95% CI = [0.32, 0.82]), social function (SMD = 0.50, 95% CI = [0.08, 0.93]), and general health (SMD = 0.36, 95% CI = [0.11, 0.61]). Improvement of the Fibromyalgia Impact Questionnaire (FIQ) scores was noted (SMD = -0.414, 95% CI = [-0.808, -0.021]), but not on the Visual Analog Scale (VAS) (SMD = -0.15, 95% CI = [-0.771, 0.471]) and the Beck's Depression Inventory (BDI) scores (SMD = -0.456, 95% CI = [-1.27, 0.30]). In conclusion, vitamin D supplementation might be an alternative option for improvement of psychological outcomes and quality of life in patients with fibromyalgia.

Systemic Factors in Temporomandibular Disorder Pain

The science of temporomandibular disorder (TMD) pain and its management has gone through significant changes during the last several decades. The authors strongly feel that the effect of systemic factors influencing TMD pain has been largely overlooked and poorly accounted for, even in established pain-management programs and protocols. The hope is that this article will act as a wake-up call for the pain management community to consider the importance of adequate knowledge of the systemic factors that affect the experience of TMD pain by the patient.

Emerging Therapies for the Management of Pain and Vaso-Occlusive Crises in Patients With Sickle Cell Disease: A Systematic Review of Randomized Controlled Trials

Sickle cell disease (SCD) is an inherited disorder that impairs red blood cells (RBCs) and disrupts the delivery of oxygen to tissues. There is currently no cure. Symptoms can appear as early as six months of age and include anemia, acute episodes of pain, swelling, infections, delayed growth, and vision problems. A growing number of therapies are being investigated for reducing these episodes of pain, also known as vaso-occlusive crises (VOCs). The research literature evidence, however, currently includes far more approaches that have not shown superiority versus placebo than ones that have been proven effective. The purpose of this systematic review is to evaluate the body of randomized controlled trials (RCTs) to determine the quality of support for and against the use of a variety of current and emerging therapies for treading SCD VOCs. Several important new papers have emerged since previous systematic reviews with similar objectives were published. This review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and focused on PubMed exclusively. Only RCTs were sought, and no other filters, except for a five-year historical timeline cut-off, were used. Of the 46 publications that were returned in response to the query, 18 were ultimately accepted as meeting the pre-established inclusion criteria. The Cochrane risk-of-bias tool was utilized as a quality assessment measure, and the GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) framework was used to assess the certainty of the evidence. Among the included publications, five out of 18 featured positive results with superiority and statistical significance versus placebo for either reduction in pain score or number/duration of VOCs. The approaches featured therapies ranging from de novo molecules to currently available drugs approved for other indications to naturally occurring metabolites such as amino acids and vitamins. A single therapy, arginine, was supported for both clinical endpoints: pain score reduction and shortened VOC duration. Currently, two therapies are approved by the United States Food and Drug Administration (FDA) and are commercially available (crizanlizumab, ADAKVEO and L-glutamine, Endari). All other therapies are investigational only in nature. Several studies included measurement of biomarker endpoints as well as clinical outcomes. Generally, beneficial outcomes related to improving biomarker levels did not also translate into statistically significant reduction of pain scores or number/duration of VOCs. While measuring biomarkers may contribute to the understanding of pathophysiology, it does not appear to directly offer predictive value toward treatment success clinically. It can be concluded that there exists a specific opportunity to design, fund, and execute investigations that both compare emerging and existing therapies versus one another and compare combinational therapies versus placebo.

Neurological susceptibility to environmental exposures: pathophysiological mechanisms in neurodegeneration and multiple chemical sensitivity

The World Health Organization lists air pollution as one of the top five risks for developing chronic non-communicable disease, joining tobacco use, harmful use of alcohol, unhealthy diets and physical inactivity. This review focuses on how host defense mechanisms against adverse airborne exposures relate to the probable interacting and overlapping pathophysiological features of neurodegeneration and multiple chemical sensitivity. Significant long-term airborne exposures can contribute to oxidative stress, systemic inflammation, transient receptor subfamily vanilloid 1 (TRPV1) and subfamily ankyrin 1 (TRPA1) upregulation and sensitization, with impacts on olfactory and trigeminal nerve function, and eventual loss of brain mass. The potential for neurologic dysfunction, including decreased cognition, chronic pain and central sensitization related to airborne contaminants, can be magnified by genetic polymorphisms that result in less effective detoxification. Onset of neurodegenerative disorders is subtle, with early loss of brain mass and loss of sense of smell. Onset of MCS may be gradual following long-term low dose airborne exposures, or acute following a recognizable exposure. Upregulation of chemosensitive TRPV1 and TRPA1 polymodal receptors has been observed in patients with neurodegeneration, and chemically sensitive individuals with asthma, migraine and MCS. In people with chemical sensitivity, these receptors are also sensitized, which is defined as a reduction in the threshold and an increase in the magnitude of a response to noxious stimulation. There is likely damage to the olfactory system in neurodegeneration and trigeminal nerve hypersensitivity in MCS, with different effects on olfactory processing. The associations of low vitamin D levels and protein kinase activity seen in neurodegeneration have not been studied in MCS. Table 2 presents a summary of neurodegeneration and MCS, comparing 16 distinctive genetic, pathophysiological and clinical features associated with air pollution exposures. There is significant overlap, suggesting potential comorbidity. Canadian Health Measures Survey data indicates an overlap between neurodegeneration and MCS (p < 0.05) that suggests comorbidity, but the extent of increased susceptibility to the other condition is not established. Nevertheless, the pathways to the development of these conditions likely involve TRPV1 and TRPA1 receptors, and so it is hypothesized that manifestation of neurodegeneration and/or MCS and possibly why there is divergence may be influenced by polymorphisms of these receptors, among other factors.

An unexpected connection: A narrative review of the associations between Gut Microbiome and Musculoskeletal Pain

PURPOSE

Multiple diverse factors contribute to musculoskeletal pain, a major cause of physical dysfunction and health-related costs worldwide. Rapidly growing evidence demonstrates that the gut microbiome has overarching influences on human health and the body's homeostasis and resilience to internal and external perturbations. This broad role of the gut microbiome is potentially relevant and connected to musculoskeletal pain, though the literature on the topic is limited. Thus, the literature on the topic of musculoskeletal pain and gut microbiome was explored.

METHODS

This narrative review explores the vast array of reported metabolites associated with inflammation and immune-metabolic response, which are known contributors to musculoskeletal pain. Moreover, it covers known modifiable (e.g., diet, lifestyle choices, exposure to prescription drugs, pollutants, and chemicals) and non-modifiable factors (e.g., gut architecture, genetics, age, birth history, and early feeding patterns) that are known to contribute to changes to the gut microbiome. Particular attention is devoted to modifiable factors, as the ultimate goal of researching this topic is to implement gut microbiome health interventions into clinical practice.

RESULTS

Overall, numerous associations exist in the literature that could converge on the gut microbiome's pivotal role in musculoskeletal health. Particularly, a variety of metabolites that are either directly produced or indirectly modulated by the gut microbiome have been highlighted.

CONCLUSION

The review highlights noticeable connections between the gut and musculoskeletal health, thus warranting future research to focus on the gut microbiome's role in musculoskeletal conditions.

The Impact of Vitamin D3 Supplementation to Topiramate Therapy on Pediatric Migraine Prophylaxis

Background:There is still a need for more studies to evaluate the role of vitamin D₃ in pediatric migraine prophylaxis. Objectives: We aimed to evaluate the effects and safety of vitamin D₃ supplementation to topiramate on pediatric migraine. Methods: A double-blinded prospective clinical trial was conducted on 5- to 14-year-old children with migraine. They were randomly assigned in a 1:1 ratio into 2 groups, one with vitamin D₃ supplementation (the supplementation group) and the other without vitamin D supplementation (the placebo group). The supplementation group received topiramate plus one 5000-IU dose of vitamin D₃ daily for 4 months. The placebo group received topiramate with a placebo capsule without any effective substances. The primary outcomes were a monthly frequency of headache attacks, a good response to intervention, and reduction in migraine severity, duration, and disability before and after treatment. Fifty-six children completed the trial. Vitamin D₃ supplementation to topiramate was more effective than the placebo group in the reduction of monthly frequency (6231.31 vs 9792.24 times, P = .01) and disability score for migraines (17 566.43 vs 25 187.65, P = .04). A good response was observed in 76.13% of patients in the vitamin D₃ supplementation group and 53.5% of patients in the placebo group, and vitamin D₃ supplementation was significantly more effective than placebo (P = .01). Side effects were observed in 13.3% and 20% of the intervention group and placebo groups, respectively, P = .5. Conclusion: Vitamin D₃ supplementation in pediatric migraine prophylaxis could be a well-tolerated, safe, and effective strategy.

Dietary Vitamin D Intake, Pain Incidence, and Pain Changes in Older Adults: The Seniors-ENRICA-1 Cohort

Background: Vitamin D plays a role in bone health, pain signaling, and inflammation. We examined the largely unknown relation of dietary vitamin D intake with pain incidence and pain changes over time in older adults. Methods: Data were taken from the Seniors-ENRICA-1 cohort, which included 950 individuals aged ≥60 years. Habitual vitamin D intake was assessed in 2012 with a validated diet history, and pain both in 2012 and 2017 with a scale ranging from 0 (no pain) to 6 (highest pain), according to its severity, frequency, and number of locations. Analyses on pain incidence and pain changes were performed in the 524 participants free of pain at baseline and the overall sample, respectively. Results: Higher dietary vitamin D intake was associated with lower 5-year pain incidence; the multivariable-adjusted odds ratio (95% confidence interval) was 0.88 (0.79,0.99) for every 1-µg/day increase in vitamin D intake, and 0.49 (0.28,0.88) for the highest (>3.52 µg/day) vs. lowest (<1.85 µg/day) tertile. Dietary vitamin D intake (highest vs. lowest tertile) was also associated with 5-year favorable pain changes: the multivariable-adjusted odds ratio of pain worsening vs. no change/pain improvement was 0.55 (0.36,0.86), and the β coefficient for changes in the pain scale was −0.56 (−1.03,−0.09). Similar results were found for pain severity, frequency, and number of pain locations. Conclusions: In an older adult population, where compliance with vitamin D intake recommendations was very low, a slightly increased dietary intake was associated with lower pain incidence and favorable pain changes over 5 years.

Evaluation of the safety, tolerability and plasma vitamin D response to long-term use of patented transdermal vitamin D patches in healthy adults: a randomised parallel pilot study

Background

Vitamin D delivered transdermally may suppress hyperactivity in nociceptor pain receptors and alter pain intensity, offering a useful addition to localised pain management in varying clinical settings. Currently, little is known about long-term usage of continuous-release vitamin D patches.

Method

We conducted a randomised parallel pilot trial to evaluate safety and tolerability of daily application of patented (US8821921B2) transdermal vitamin D patches over 8 weeks and assess time-level profile of serum vitamin D. Compliance, tolerance and sun exposure were monitored daily, serum 25(OH)D measured 2-weekly and dietary intake and safety markers 4-weekly.

Results

Thirty healthy adults were randomised to two treatment groups: big patch and small patch. mean age was 36 years (20-68 years) with a 63% female to 37% male split. Patches differed in size but contained identical ingredients including 30 000 IU cholecalciferol. Physical and blood safety markers remained stable, within normal clinical parameters, and with no clinically meaningful changes throughout. Five big patch participants experienced skin irritation, which was mild and occasional for three, but continuous for two leading to patch withdrawal. There were no skin reactions in small patch group. average, serum 25(OH)D levels increased by +14 nmol/L (SD 11.63, range, -4 to 40 nmol/L) between baseline and week 8, with no significant differences between patch sizes. There was a shift in overall vitamin D status between baseline and week 8 (23% deficient (<30 nmol/L) decreasing to 0%, and normal (>50 nmol/L) increasing from 37% to 70% at week 8).

Conclusion

Based on these results, long-term (8 weeks) application of patented transdermal vitamin D patches was found to be safe. There may be minor skin tolerance issues with big patches for some, which appears to relate to patch size. Larger trials are warranted to explore the increase in vitamin D levels beyond 8 weeks.

Trial registration number

NCT04851990.

The efficacy of vitamin D in treatment of fibromyalgia: a meta-analysis of randomized controlled studies and systematic review

BACKGROUND

Recent studies have found potential benefits of vitamin D in relieving pain, while the results from randomized controlled trials of vitamin D for fibromyalgia have been promising. We conducted a systematic review and meta-analysis to evaluate the efficacy of vitamin D in the treatment of fibromyalgia.

RESEARCH DESIGN AND METHODS

PubMed, Web of Science, Embase, and Cochrane Library databases were systematically searched. The language used was limited to English. We selected only randomized controlled studies that reported vitamin D versus placebo-controlled cure for fibromyalgia. After extracting valid data, a meta-analysis was performed using Stata version 12.0. The major outcome in the pooled analysis was the Fibromyalgia Impact Questionnaire and Visual Analogue Scale (VAS) changes in fibromyalgia patients before and after treatment. The pooled effects were analyzed as mean differences and 95% confidence intervals.

RESULTS

: Five studies including 315 participants were identified. These studies found that vitamin D was effective in reducing Fibromyalgia Impact Questionnaire scores compared with that in the control group, with significant differences (weighted mean difference = -7.82, 95% confidence interval: -12.05 to -3.59, P < 0.001). However, there was no statistical difference in VAS between the two groups (weighted mean difference = -0.60, 95% confidence interval: -1.38 to 0.17, P > 0.05).

CONCLUSIONS

Data from randomized controlled studies suggest that vitamin D supplementation may be an effective fibromyalgia therapeutic approach.

Review on Headache Related to Dietary Supplements

PURPOSE OF REVIEW

The lifetime prevalence of headaches is 96%. Approximately 11% of the adult population worldwide has a migraine headache. Migraine is a complex disorder that is more than a simple headache. So far, many underlying mechanisms, i.e. inflammatory, vascular, neurogenic have been hypothesized. In recent years evidences proposed that an energy deficit due to changes in mitochondrial function contributes to migraine pathophysiology as an upstream disorder. Recent insights suggested that the coexistence of sensory-stimuli surplus and energy-reserve shortage activate the trigeminovascular system. Some nutrients are considered as essential elements in mitochondrial bioenergetics and some others are known as natural immuno-modulatory components. Also, evidence showed their beneficial effect in headache prophylaxis and treatment. In present study, we aimed to review the available data in this field.

RECENT FINDINGS

Vitamin B group, magnesium, and Coenzyme Q10 (CoQ10) are well-known for their function in mitochondrial energy metabolism. On the other hand, studies support their beneficial role in controlling migraine headache symptoms. For instance, daily intake of 400-milligram riboflavin for 3 months resulted in more than 50% reduction in migraine attacks in more than half of the consumers. According to recent evidence, vitamin D and Omega-3 which are considered as famous immune-modulatory compounds are also reported to be effective in migraine prophylaxis. For example, every 22% reduction in migraine headache occurrence was reported for every 5 ng/ml rise in serum vitamin D. Supplementation with vitamin B group, CoQ10, magnesium, vitamin D and Omega-3 could be considered as an effective, less costly strategy in headache/migraine prophylaxis.

The Role of Nutrient Supplementation in the Management of Chronic Pain in Fibromyalgia: A Narrative Review

INTRODUCTION

The multifaceted clinical presentation of fibromyalgia (FM) supports the modern understanding of the disorder as a more global condition than one simply affecting pain sensation. The main pharmacologic therapies used clinically include anti-epileptics and anti-depressants. Conservative treatment options include exercise, myofascial release, psychotherapy, and nutrient supplementation.

METHODS

Narrative review.

RESULTS

Nutrient supplementation is a broadly investigated treatment modality as numerous deficiencies have been linked to FM. Additionally, a proposed link between gut microbiome patterns and chronic pain syndromes has led to studies investigating probiotics as a possible treatment. Despite positive results, much of the current evidence regarding this topic is of poor quality, with variable study designs, limited sample sizes, and lack of control groups.

CONCLUSIONS

The etiology of FM is complex, and has shown to be multi-factorial with genetics and environmental exposures lending influence into its development. Preliminary results are promising, however, much of the existing evidence regarding diet supplementation is of poor quality. Further, more robust studies are needed to fully elucidate the potential of this alternative therapeutic option.

Could ferritin, vitamin B12, and vitamin D play a role in the etiopathogenesis of fibromyalgia syndrome?

Introduction. Fibromyalgia syndrome (FS) comprises general body pain, sleep disturbances, and fatigue. Vitamin B₁₂ (VB), vitamin D (VD), and iron deficiencies lead to similar complaints. First, this study aimed to evaluate the VB, VD, and ferritin levels of patients with FS. Second, it aimed to investigate whether there was a relationship between these parameters and FS severity. Material and methods. The study included 58 female patients with FS and 58 healthy females as a control group. The patients completed the Fibromyalgia Impact Questionnaire (FIQ), Visual Analog Scale (VAS), fatigue questionnaire, Pittsburgh sleep quality scale, and the Short Form-36 (SF-36). This study examined the VD, VB, and ferritin levels of the patient and control groups. Results. The VB (240.0 [110.0-394.0] vs 291.0 [210.0-609.0] pg/ml, p<0.001), VD (12.5 [3.0-45.0] vs 20.0 [5.0-54.0] ng/ml, p=0.013), and ferritin levels (21.2 [4.0-86.0] vs 32.0 [7.1-120.0], ng/ml, p=0.009) of the FS patients were determined to be significantly lower than those of the control group. A negative correlation was determined between the number of tender points and VB, VD, and ferritin levels. In the regression analysis, we found low ferritin levels (odds ratio [OR] 1.036, 95% confidence interval [CI] 1.015-1.058, p<0.001) and VB (OR 1.010, CI 1.002-1.018, p=0.010) to be an independent risk factor for FS. Conclusions. There may be a relationship between VB, VD, and ferritin levels and the number of tender points in patients with FS. Levels of iron and VB may play a vital role in FS etiopathogenesis. However, VD levels may not be a risk factor for FS etiopathogenesis.

TRPV1 channels as a newly identified target for vitamin D

Vitamin D is known to elicit many biological effects in diverse tissue types and is thought to act almost exclusively upon its canonical receptor within the nucleus, leading to gene transcriptional changes and the subsequent cellular response. However, not all the observed effects of vitamin D can be attributed to this sole mechanism, and other cellular targets likely exist but remain to be identified. Our recent discovery that vitamin D is a partial agonist of the Transient Receptor Potential Vanilloid family 1 (TRPV1) channel may provide new insights as to how this important vitamin exerts its biological effects either independently or in addition to the nuclear vitamin D receptor. In this review, we discuss the literature surrounding this apparent discrepancy in vitamin D signaling and compare vitamin D with known TRPV1 ligands with respect to their binding to TRPV1. Furthermore, we provide evidence supporting the notion that this novel vitamin D/TRPV1 axis may explain some of the beneficial actions of this vitamin in disease states where TRPV1 expression and vitamin D deficiency are known to overlap. Finally, we discuss whether vitamin D may also act on other members of the TRP family of ion channels.

Combined Effect of Vitamin D Supplementation and Physiotherapy on Reducing Pain Among Adult Patients With Musculoskeletal Disorders: A Quasi-Experimental Clinical Trial

Background: The prevalence of musculoskeletal disorders (MSD) and vitamin D insufficiency is high. Past research indicating vitamin D supplementation and physiotherapy are useful for the treatment of MSDs. However, to the best of our knowledge, the combined benefits of vitamin D and physiotherapy are not yet evaluated in MSD. We hypothesized that combined intervention of vitamin D supplementation and physiotherapy would be more effective in relieving the pain of MSD compared to only physiotherapy intervention.

Objective: This study aimed to examine whether combined effect of vitamin D supplementation and physiotherapy was better than physiotherapy alone in reducing pain-related outcomes (e.g., pain severity, affective interference, and physical interference) in patients with MSD.

Methods: A quasi-clinical experiment was conducted between May 2020 and April 2021. Vitamin D level in the blood was measured at the start of the study. Patients with vitamin D levels <20 ng/mL were assigned to the combined physiotherapy and vitamin D group. The physiotherapy group consisted of the patients with vitamin D levels more than 20 ng/mL. The Brief Pain Inventory scale was utilized to measure pain at baseline and after 12 weeks of interventions. We used the paired t-tests for unadjusted analysis. Further, a linear regression model was used to identify the combined effect of physiotherapy and vitamin D on reducing pain scores after adjusting potential confounders.

Results: Combined intervention of vitamin D and physiotherapy showed significantly better results than only physiotherapy intervention in the reduction of three pain-related outcomes (p < 0.001). The multivariable analysis indicated that the combination of physiotherapy and vitamin D treatment reduced pain score by 1.126 (slope = −1.126, p = 0.035) compared to physiotherapy alone.

Conclusion: Combined intervention (vitamin D with physiotherapy) had a better pain-relieving effect than physiotherapy alone. To confirm these findings, more research is needed with randomized control trials.

Clinical Trial Registration: [http://ctri.nic.in/Clinicaltrials/advancesearchmain.php], identifier [CTRI/2020/04/024845].

Vitamin D and Rheumatic Diseases: A Review of Clinical Evidence

Vitamin D plays an important role in maintaining a healthy mineralized skeleton. It is also considered an immunomodulatory agent that regulates innate and adaptive immune systems. The aim of this narrative review is to provide general concepts of vitamin D for the skeletal and immune health, and to summarize the mechanistic, epidemiological, and clinical evidence on the relationship between vitamin D and rheumatic diseases. Multiple observational studies have demonstrated the association between a low level of serum 25-hydroxyvitamin D [25(OH)D] and the presence and severity of several rheumatic diseases, such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), spondyloarthropathies, and osteoarthritis (OA). Nevertheless, the specific benefits of vitamin D supplements for the treatment and prevention of rheumatic diseases are less accepted as the results from randomized clinical trials are inconsistent, although some conceivable benefits of vitamin D for the improvement of disease activity of RA, SLE, and OA have been demonstrated in meta-analyses. It is also possible that some individuals might benefit from vitamin D differently than others, as inter-individual difference in responsiveness to vitamin D supplementation has been observed in genomic studies. Although the optimal level of serum 25(OH)D is still debatable, it is advisable it is advisable that patients with rheumatic diseases should maintain a serum 25(OH)D level of at least 30 ng/mL (75 nmol/L) to prevent osteomalacia, secondary osteoporosis, and fracture, and possibly 40–60 ng/mL (100–150 nmol/L) to achieve maximal benefit from vitamin D for immune health and overall health.

The Role of Vitamin D in the Management of Chronic Pain in Fibromyalgia: A Narrative Review

INTRODUCTION

Fibromyalgia (FM) is a complex disorder characterized primarily by chronic, widespread musculoskeletal pain. Currently, the Food and Drug Administration (FDA) has approved the use of three medications to treat FM: pregabalin, duloxetine, and milnacipran. The pharmaceutical intervention has lacked consistent pain relief among all patients. Therefore, the investigation into alternative treatment options has grown in interest. This narrative review aims to evaluate the evidence regarding vitamin D for the treatment of FM.

METHODS

Narrative review.

RESULTS

Low serum vitamin D has been linked to various chronic pain states. An association between vitamin D deficiency and FM has been reported but is controversial in the literature. Some studies have documented the beneficial effects of vitamin D supplementation on reducing pain symptoms and improving the overall quality of life in those with FM. Despite these positive findings, many of the studies regarding this topic lack adequate power to make substantial conclusions about the effects of vitamin D on FM.

CONCLUSION

Existing studies provide promising results. However, additional high-quality data on vitamin D supplementation is needed before recommendations for pain management can be made. Vitamin D supplementation is inexpensive, has minimal side effects, and can benefit FM patients regardless of its efficacy in pain control. Additionally, high-quality studies are warranted to fully elucidate the potential of vitamin D to manage chronic pain in FM.

Efficacy and safety of weekly vitamin D3 in patients with fibromyalgia: 12-week, double-blind, randomized, controlled placebo trial

INTRODUCTION

FM is a chronic musculoskeletal disorder characterized by the presence of generalized pain. There are contradictory results regarding the prevalence and supplementation effect of vitamin D deficiency on FM patients. We aim to determine the safety and efficacy of a 12-week vitamin D supplementation on FM patients.

METHODS

We conducted a randomized, placebo-controlled, double-blind clinical trial. We included female participants of 18 years old or older, who met 1990 or 2010 ACR criteria for fibromyalgia. The Spanish validated FIQ and the VAS of pain were applied at baseline. The participants were then randomized to receive placebo or 50,000 IU of Vitamin D₃ PO, weekly for 12 weeks.

RESULTS

We included 80 patients. There was no statistical difference in the initial and final FIQ between both groups. The FIQ delta also did not prove to be different at the end of the study. The increase in vitamin D levels in the intervention group was corroborated. Regarding serious adverse effects, none was reported in both groups. There was no statistical difference in minor adverse events.

CONCLUSION

In this double-blind placebo-controlled randomized study conducted to measure the efficacy and safety of vitamin D exclusively in patients with FM, we found that there is no evidence of a trend in favor of vitamin D treatment, since we did not observe improvement in the VAS of pain or FIQ.

TRIAL REGISTRY

Clinical Trials.gov number: NCT03369379 Key Points • There are conflicting results in vitamin D to treat fibromyalgia. • In this double-blind, randomized controlled trial, we did not find a difference in the VAS nor FIQ with vitamin D supplementation. • The increase in vitamin D levels in the intervention group was corroborated.

Peritraumatic Vitamin D levels predict chronic pain severity and contribute to racial differences in pain outcomes following Major Thermal Burn Injury

Major thermal burn injuries result in approximately 40,000 hospitalizations in the United States each year. Chronic pain affects up to 60% of burn survivors, Black Americans have worse chronic pain outcomes than White Americans. Mechanisms of chronic pain pathogenesis after burn injury, and accounting for these racial differences, remain poorly understood. Due to socioeconomic disadvantage and differences in skin absorption, Black Americans have an increased prevalence of Vitamin D deficiency. We hypothesized that peritraumatic Vitamin D levels predict chronic pain outcomes after burn injury and contribute to racial differences in pain outcomes. Among burn survivors (n=77, 52% White, 48% Black, 77% male), peritraumatic Vitamin D levels were more likely to be deficient in Blacks vs. Whites (27/37 (73%) vs. 14/40 (35%), p<.001). Peritraumatic Vitamin D levels were inversely associated with chronic post-burn pain outcomes across all burn injury survivors, including those who were and were not Vitamin D deficient, and accounted for approximately 1/3 of racial differences in post-burn pain outcome. Future studies are needed to evaluate potential mechanisms mediating the effect of Vitamin D on post-burn pain outcomes and the potential efficacy of Vitamin D in improving pain outcomes and reducing racial differences.

Clustering fibromyalgia patients: A combination of psychosocial and somatic factors leads to resilient coping in a subgroup of fibromyalgia patients

Background

Coping strategies and their efficacy vary greatly in patients suffering from fibromyalgia syndrome (FMS).

Objective

We aimed to identify somatic and psychosocial factors that might contribute to different coping strategies and resilience levels in FMS.

Subjects and methods

Standardized questionnaires were used to assess coping, pain, and psychological variables in a cohort of 156 FMS patients. Quantitative real-time polymerase chain reaction (qRT-PCR) determined gene expression of selected cytokines in white blood cells of 136 FMS patients and 25 healthy controls. Data of skin innervation, functional and structural sensory profiles of peripheral nociceptive nerve fibers of a previous study were included into the statistics. An exploratory factor analysis was used to define variance explaining factors, which were then included into cluster analysis.

Results

54.9% of the variance was explained by four factors which we termed (1) affective load, (2) coping, (3) pain, and (4) pro-inflammatory cytokines (p < 0.05). Considering differences in the emerged factors, coping strategies, cytokine profiles, and disability levels, 118 FMS patients could be categorized into four clusters which we named “maladaptive”, “adaptive”, “vulnerable”, and “resilient” (p < 0.05). The adaptive cluster had low scores in disability and in all symptom categories in contrast to the vulnerable cluster, which was characterized by high scores in catastrophizing and disability (p < 0.05). The resilient vs. the maladaptive cluster was characterized by better coping and a less pro-inflammatory cytokine pattern (p < 0.05).

Conclusion

Our data suggest that problem- and emotion-focused coping strategies and an anti-inflammatory cytokine pattern are associated with reduced disability and might promote resilience. Additional personal factors such as low anxiety scores, ability of acceptance, and persistence further favor a resilient phenotype. Individualized therapy should take these factors into account.

Food Implications in Central Sensitization Syndromes

Fibromyalgia (FM), chronic fatigue syndrome (CFS) and multiple chemical sensitivity (MCS) are some of the central sensitization syndromes (CSSs). The complexity of their diagnosis, the high interindividual heterogeneity and the existence of multi-syndromic patients requires a multifaceted treatment. The scientific literature is contradictory regarding the role of food in CSS, and evidence on the role of nutrition in MCS is particularly scarce. This review consists in gathering information about the current status of dietary recommendations (i.e., special dietary interventions, the role of additives, presence of micronutrient deficiencies, nutritional supplements and elimination of other nutrients and substances) and discussing the scientific evidence in depth to shed light on appropriate nutritional treatment managements for CSS patients. Current indications show that dietary modifications may vastly improve the patients’ quality of life at a low cost. We suggest personalized treatment, taking into consideration the severity of the disease symptoms, quality of life, coexistence with other diseases, pharmacological treatment, changing clinical characteristics, nutritional status, energy requirements and food tolerances, among others, as the best ways to tailor specific dietary interventions. These approaches will partially overcome the lack of scientific and clinical research on MSC. Patients should also be advised on the serious consequences of following dietary guidelines without a dietitian’s and clinician’s supervision.

Vitamin D is an endogenous partial agonist of the transient receptor potential vanilloid 1 channel

KEY POINTS

25-Hydroxyvitamin D (25OHD) is a partial agonist of TRPV1 whereby 25OHD can weakly activate TRPV1 yet antagonize the stimulatory effects of the full TRPV1 agonists capsaicin and oleoyl dopamine. 25OHD binds to TRPV1 within the same vanilloid binding pocket as capsaicin. 25OHD inhibits the potentiating effects of PKC-mediated TRPV1 activity. 25OHD reduces T-cell activation and trigeminal neuron calcium signalling mediated by TRPV1 activity. These results provide evidence that TRPV1 is a novel receptor for the biological actions of vitamin D in addition to the well-documented effects of vitamin D upon the nuclear vitamin D receptor. The results may have important implications for our current understanding of certain diseases where TRPV1 and vitamin D deficiency have been implicated, such as chronic pain and autoimmune diseases, such as type 1 diabetes.

ABSTRACT

The capsaicin receptor TRPV1 plays an important role in nociception, inflammation and immunity and its activity is regulated by exogenous and endogenous lipophilic ligands. As vitamin D is lipophilic and involved in similar biological processes as TRPV1, we hypothesized that it directly regulates TRPV1 activity and function. Our calcium imaging and electrophysiological data demonstrate that vitamin D (25-hydroxyvitamin D (25OHD) and 1,25-hydroxyvitamin D (1,25OHD)) can weakly activate TRPV1 at physiologically relevant concentrations (100 nM). Furthermore, both 25OHD and 1,25OHD can inhibit capsaicin-induced TRPV1 activity (IC50  = 34.3 ± 0.2 and 11.5 ± 0.9 nM, respectively), but not pH-induced TRPV1 activity, suggesting that vitamin D interacts with TRPV1 in the same region as the TRPV1 agonist capsaicin. This hypothesis is supported by our in silico TRPV1 structural modelling studies, which place 25OHD in the same binding region as capsaicin. 25OHD also attenuates PKC-dependent TRPV1 potentiation via interactions with a known PKC phospho-acceptor residue in TRPV1. To provide evidence for a physiological role for the interaction of vitamin D with TRPV1, we employed two different cellular models known to express TRPV1: mouse CD4+ T-cells and trigeminal neurons. Our results indicate that 25OHD reduces TRPV1-induced cytokine release from T-cells and capsaicin-induced calcium activity in trigeminal neurons. In summary, we provide evidence that vitamin D is a novel endogenous regulator of TRPV1 channel activity that may play an important physiological role in addition to its known effects through the canonical nuclear vitamin D receptor pathway.

Perioperative Serum 25-Hydroxyvitamin D Levels as a Predictor of Postoperative Opioid Use and Opioid Use Disorder: a Cohort Study

IMPORTANCE

Vitamin D deficiency is associated with chronic pain syndromes and higher opioid use among cancer patients, but its association with opioid use among opioid-naïve subjects following a major surgical procedure with acute pain has not been explored.

OBJECTIVE

To determine the association between serum 25-hydroxyvitamin D (25(OH)D) levels, opioid use, and opioid use disorder.

METHODS

We identified commercially insured subjects aged 18-64 years with available perioperative serum 25-hydroxyvitamin D (25D) levels who underwent one of nine major surgical procedures in 2000-2014. Primary outcomes were dose and duration of opioid use measured using pharmacy claims. Secondary outcome was opioid use disorder captured using diagnosis codes. Multivariable negative binomial models with generalized estimating equations were performed examining the association between 25D levels and postoperative opioid use measures, adjusting for age, sex, race/ethnicity, Charlson score, education, income, latitude, and season of blood draw. Adjusted Cox regression was used to examine the association with opioid use disorder.

RESULTS

Among 5446 subjects, serum 25(OH)D was sufficient (≥ 20 ng/mL) among 4349 (79.9%) subjects, whereas 837 (15.4%) had insufficient (12 to < 20 ng/mL) and 260 (4.8%) had deficient (< 12 ng/mL) levels. On multivariable analysis, as compared with subjects with sufficient 25(OH)D levels, subjects with deficient 25(OH)D levels had 1.7 more days (95% CI 0.76, 2.58) of opioid use per year and had 98.7 higher morphine milligram equivalent dose (95% CI 55.7, 141.8) per year. Among 11,713 study cohort, subjects with deficient 25(OH)D levels were more likely to be diagnosed with opioid use disorders (HR 2.41; 95% CI 1.05, 5.52).

CONCLUSION

Patients undergoing common surgical procedures with deficient 25D levels are more likely to have higher opioid use and an increased risk of opioid use disorder compared to those with sufficient levels. Serum 25D levels may serve as a biomarker to identify subjects at increased risk of opioid misuse.

Vitamin D Supplementation Improves Health-Related Quality of Life and Physical Performance in Children with Sickle Cell Disease and in Healthy Children

INTRODUCTION

No study determined if vitamin D supplementation improves health-related quality of life (HRQL) using pediatric Patient-Reported Outcomes Measurement Information System or physical functioning in type SS sickle cell disease (HbSS).

METHOD

Subjects with HbSS (n = 21) and healthy subjects (n = 23) were randomized to daily oral doses (4,000 vs. 7,000 IU) of cholecalciferol (vitamin D3) and evaluated at 6 and 12 weeks for changes in serum 25 hydroxyvitamin D (25(OH)D), HRQL, and physical functioning.

RESULTS

In subjects with HbSS, significant reductions in pain, fatigue, and depressive symptoms and improved upper-extremity function were observed. In healthy subjects, significant reductions in fatigue and improved upper-extremity function were observed. Significant improvements in peak power and dorsiflexion isometric maximal voluntary contraction torques were observed in both groups. In subjects with HbSS, improved plantar flexion isometric maximal voluntary contraction torques were observed. Both groups saw significant improvement in their total Bruininks-Oseretsky Test of Motor Proficiency score.

DISCUSSION

Daily high-dose vitamin D supplementation for African American children with and without HbSS improved HRQL and physical performance.

Exposure to greenspaces could reduce the high global burden of pain

Painful conditions are among the leading causes of years lived with disability, and may increase following the coronavirus pandemic, which has led to temporary closure of some healthcare services for people with chronic pain. To reduce this burden, novel, cost-effective and accessible interventions are required. We propose that greenspace exposure may be one such intervention. Drawing on evidence from neuroscience, physiology, microbiology, and psychology, we articulate how and why exposure to greenspaces could improve pain outcomes and reduce the high global burden of pain. Greenspace exposure potentially provides opportunities to benefit from known or proposed health-enhancing components of nature, such as environmental microbiomes, phytoncides, negative air ions, sunlight, and the sights and sounds of nature itself. We review the established and potential links between these specific exposures and pain outcomes. While further research is required to determine possible causal links between greenspace exposure and pain outcomes, we suggest that there is already sufficient evidence to help reduce the global burden of pain by improving access and exposure to quality greenspaces.

Vitamin D Megadose: Definition, Efficacy in Bone Metabolism, Risk of Falls and Fractures

Introduction

Currently, approximately more than one billion people around the world are considered to have deficient levels of vitamin D. International consensus recommends vitamin D supplementation to high-risk patients (advanced age, osteoporosis, liver failure, malabsorption syndromes, etc.) and those with levels below 30 ng/mL. There are several vitamin D formulations and dosages available, including megadoses. At the moment, there is no consensus on the definition of megadoses. The purpose of this review is to define what is a megadose and analyze its effectiveness in bone metabolism, risk of fractures and falls.

Conclusion

The administration of doses higher than 100,000 IU of vitamin D is considered a megadose. It is evident that the use of megadoses increases serum concentrations of vitamin D; however, there has been no evidence of a decrease in the risk of falls, vertebral fractures or changes in bone mineral density.

Vitamin D levels in relation to low back pain during adolescence

This study aimed to investigate the association between 25-hydroxyvitamin D (25(OH)D) level and low back pain (LBP) among adolescents while adjusting for potential confounders pertinent to this age group including the weight of school bags, BMI and physical activity. A cross-sectional study was conducted on 760 randomly selected adolescents in middle schools. Data on LBP and the risk factors for LBP were collected from parents by a self-administered questionnaire and from adolescents by face-to-face interview. Blood samples were tested in an accredited laboratory; and 25(OH)D was measured using liquid chromatography-tandem MS. The lifetime prevalence and the 6-month prevalence of LBP were 32·28 (95 % CI 28·97, 35·73) % and 21·26 (95 % CI 18·40, 24·33) %, respectively. There was no difference in the geometric mean of 25(OH)D between those with and without LBP in the past 6 months (28·50 nmol/l and 30·82 nmol/l, respectively; P = 0·122). There was no association between 25(OH)D and LBP in the univariable or multivariable analysis whether 25(OH)D fitted as a continuous or as a categorical variable. We found no association between vitamin D level and LBP in adolescents in an area with high prevalence of vitamin D deficiency. Although it is important to have sufficient vitamin D levels during adolescence for several other health benefits, we concluded that vitamin D is not a major determinant for LBP among adolescents in our setting.

The effects of vitamin D supplementation on interictal serum levels of calcitonin gene-related peptide (CGRP) in episodic migraine patients: post hoc analysis of a randomized double-blind placebo-controlled trial

Background

Emerging evidence showed promising effects of vitamin D on headaches characteristics. Thus, it seems there is still a need for more researches to clarify the mechanisms by which this vitamin exerts anti-migraine effects.

Methods

The present study was conducted as a 16-week randomized double-blind placebo-controlled trial on 80 episodic migraine patients allocated in 2 parallel groups each consisted of 40 patients who received vitamin D 2000 IU/d or placebo. At baseline and after the intervention completion, headache diaries and migraine disability assessment questionnaire (MIDAS) were used to assess migraine related variables in patients. Also, interictal serum concentration of calcitonin gene-related peptide (CGRP) (as the dominant mediator of migraine pain pathogenesis) was evaluated using ELISA method.

Results

The mean (SD) of age in the vitamin D and placebo groups was 37 (8) and 38 (12) years, respectively. ANCOVA test adjusted for baseline values, and confounders showed vitamin D supplementation resulted in a significant improvement in MIDAS score after 12 weeks in the intervention group (21.49 (16.22–26.77)) compared to placebo (31.16 (25.51–36.82) P value: 0.016). Moreover, after controlling for baseline levels, and other variables using ANCOVA, CGRP level was appeared to be significantly lower following vitamin D supplementation (153.26 (133.03–173.49) ng/L) than the patients in the placebo arm (188.35 (167.15–209.54) ng/L) (P value = 0.022).

Conclusion

According to the current findings, vitamin D supplementation in episodic migraineurs, particularly in those with migraine with aura, may potentially improve migraine headache characteristics and disability probably through attenuating CGRP levels. Therefore, these results could provide a new insight into anti-nociceptive effects of vitamin D; however, more studies are required to confirm our findings.

Trial registration

The trial is registered in the Iranian registry of clinical trials (IRCT) at 11 July 2018, with IRCT code: IRCT20151128025267N6.

The effect of vitamin D replacement on spinal inhibitory pathways in women with chronic widespread pain

Vitamin D replacement helps in pain reduction in patients with chronic widespread pain (CWP). But the current literature lack studies that investigate its mechanism. Cutaneous silent period (CSP) is the electrophysiologic analog of the spinal inhibitory pathways and an objective method to document their involvement. This study aims to show if vitamin D replacement has an effect on the spinal inhibitory pathways through CSP parameters. Female patients who have CWP with vitamin D deficiency were included. Patients received an 8-week replacement therapy of vitamin D. Patients' pain were evaluated using the visual analog scale (VAS) and Leeds assessment of neuropathic symptoms and signs pain scale (LANSS). Quality of life with Nottingham Health Profile (NHP) and CSP parameters were also recorded before and after treatment. A total of 51 patients were included in the final analyses. The mean age of the patients was 44.3 ± 12.7 (minimum 18-maximum 65). Mean symptom duration was 13.1 ± 6.7 (minimum3-maximum 24) months. Patients' mean BMI was 21.6 ± 3.9 (minimum 18.0 maximum 29.1). Patients' median VAS and LANSS scores decreased significantly (p < 0.01) and NHP scores improved significantly in all subsets (p < 0.01). Vitamin D replacement did not significantly change CSP latency and duration (p = 0.06 and p = 0.12).Vitamin D replacement does not seem to work via modifying the spinal inhibitory pathways that are involved in the formation of the cutaneous silent period. This is the first study to objectively investigate the effect of vitamin D replacement on central sensitization mechanisms.

Vitamin D in migraine headache: a comprehensive review on literature

INTRODUCTION

As a primary headache, migraine has been established as the first leading disability cause worldwide in the subjects who aged less than 50 years. A variety of dietary supplements have been introduced for migraine complementary treatment. As an anti-inflammatory and antioxidant agent, vitamin D is one of these agents which has been of interest in recent years. Although higher prevalence of vitamin D deficiency/insufficiency has been highlighted among migraineurs compared to controls, there is not any consensus in prescribing vitamin D in clinical practice. Therefore, in the current review, in addition to observational and case-control studies, we also included clinical trials concerning the effects of vitamin D supplementation on migraine/headache.

METHODS

Based on a PubMed/MEDLINE and ScienceDirect database search, this review study includes published articles up to June 2019 concerning the association between migraine/headache and vitamin D status or supplementation.

RESULTS

The percentage of subjects with vitamin D deficiency and insufficiency among migraineurs and headache patients has been reported to vary between 45 and 100%. In a number of studies, vitamin D level was negatively correlated with frequency of headaches. The present findings show that supplementation with this vitamin in a dose of 1000-4000 IU/d could reduce the frequency of attacks in migraineurs.

CONCLUSION

It seems a high proportion of migraine patients might suffer from vitamin D deficiency/insufficiency. Further, the current evidence shows that in addition to routine drug therapy, vitamin D administration might reduce the frequency of attacks in migraineurs. However, these results have yet to be confirmed.

Insights on Nutrients as Analgesics in Chronic Pain

Many serious inflammatory disorders and nutrient deficiencies induce chronic pain, and anti-inflammatory diets have been applied successfully to modify the inflammatory symptoms causing chronic pain. Numerous scientific data and clinical investigations have demonstrated that long-term inflammation could lead to an inappropriate or exaggerated sensibility to pain. In addition, some Non-steroidal Anti-inflammatory Drugs (NSAID), which directly act on the many enzymes involved in pain and inflammation, including cyclooxygenases, are used to dampen the algesic signal to the central nervous system, reducing the responses of soft C-fibers to pain stimuli. On the other hand, there are a few reports from both health authorities and physicians, reporting that decreased transmission of pain signals can be achieved and improved, depending on the patient's dietary habit. Many nutrients, as well as a suitable level of exercise (resistance training), are the best methods for improving the total mitochondrial capacity in muscle cells, which can lead to a reduction in sensitivity to pain, particularly by lowering the inflammatory signaling to C-fibers. According to the current literature, it could be proposed that chronic pain results from the changed ratio of neuropeptides, hormones, and poor nutritional status, often related to an underlying inflammatory disorder. The current review also evaluates the effective role of nutrition-related interventions on the severity of chronic pain. This review pointed out that nutritional interventions can have a positive effect on pain experience through the indirect inhibitory effect on prostaglandin E2 and attenuation of mitochondrial dysfunction caused by ischemia/reperfusion in skeletal muscle, improving the intracellular antioxidant defense system. These data highlight the need for more nutrition studies where chronic pain is the primary outcome, using accurate interventions. To date, no nutritional recommendation for chronic pain has been officially proposed. Therefore, the goal of this article is to explore pain management and pain modulation, searching for a mode of nutrition efficient in reducing pain.

Cholecalciferol (Vitamin D3) Reduces Rat Neuropathic Pain by Modulating Opioid Signaling

The impact of vitamin D on sensory function, including pain processing, has been receiving increasing attention. Indeed, vitamin D deficiency is associated with various chronic pain conditions, and several lines of evidence indicate that vitamin D supplementation may trigger pain relief. However, the underlying mechanisms of action remain poorly understood. We used inflammatory and non-inflammatory rat models of chronic pain to evaluate the benefits of vitamin D₃ (cholecalciferol) on pain symptoms. We found that cholecalciferol supplementation improved mechanical nociceptive thresholds in monoarthritic animals and reduced mechanical hyperalgesia and cold allodynia in a model of mononeuropathy. Transcriptomic analysis of cerebrum, dorsal root ganglia, and spinal cord tissues indicate that cholecalciferol supplementation induces a massive gene dysregulation which, in the cerebrum, is associated with opioid signaling (23 genes), nociception (14), and allodynia (8), and, in the dorsal root ganglia, with axonal guidance (37 genes) and nociception (17). Among the identified cerebral dysregulated nociception-, allodynia-, and opioid-associated genes, 21 can be associated with vitamin D metabolism. However, it appears that their expression is modulated by intermediate regulators such as diverse protein kinases and not, as expected, by the vitamin D receptor. Overall, several genes-Oxt, Pdyn, Penk, Pomc, Pth, Tac1, and Tgfb1-encoding for peptides/hormones stand out as top candidates to explain the therapeutic benefit of vitamin D₃ supplementation. Further studies are now warranted to detail the precise mechanisms of action but also the most favorable doses and time windows for pain relief.

Autoinflammatory/autoimmunity syndrome induced by adjuvants (ASIA; Shoenfeld's syndrome): A new flame

In the present review, recent findings regarding autoimmune/inflammatory syndrome by adjuvants (ASIA) are described. Patients with ASIA present with complaints such as fatigue, cognitive impairment, arthralgias, myalgias, pyrexia, dry eyes and dry mouth. During the last few years, it has been postulated that these symptoms in patients with foreign body implants are due to a chronic inflammatory process and an adjuvant effect of the implanted biomaterial. Ultimately, these inflammatory reactions result in (an increase of) allergies, autoimmune diseases, immune deficiency and/or lymphomas. Pre-existent allergic disease has been found to be an important risk factor for the development of ASIA after foreign body implantation. Explantation of the foreign body results in the majority of patients in an amelioration of the symptoms. There is an urgent need to start adequately adjusted epidemiological studies to obtain better evidence which percentage of patients does develop symptoms and/or diseases such as ASIA, immune deficiency, and/or autoimmune diseases after implant surgery.

Is there an association between vitamin D status and risk of chronic low back pain? A nested case-control analysis in the Nord-Trøndelag Health Study

OBJECTIVES

To explore potential associations between vitamin D status and risk of chronic low back pain (LBP) in a Norwegian cohort, and to investigate whether relationships depend on the season of blood sample collection.

DESIGN

A nested case-control study in a prospective data set.

SETTING

The Norwegian community-based Nord-Trøndelag Health Study (HUNT). Data were collected in the HUNT2 (1995-1997) and HUNT3 (2006-2008) surveys.

MAIN OUTCOME MEASURE

Chronic LBP, defined as LBP persisting at least 3 months continuously during the past year.

PARTICIPANTS

Among individuals aged 19-55 years without LBP in HUNT2, a data set was generated including 1685 cases with LBP in HUNT3 and 3137 controls without LBP.

METHODS

Blood samples from the participants collected in HUNT2 were analysed for serum 25-hydroxyvitamin D (25(OH)D) level. Associations with LBP in HUNT3 were evaluated by unconditional logistic regression analysis with adjustment for age, sex, work status, physical activity at work and in leisure time, education, smoking, and body mass index.

RESULTS

No association between vitamin D status and risk of chronic LBP was found in the total data set (OR per 10 nmol/L 25(OH)D=1.01, 95% CI 0.97 to 1.06) or in individuals with blood samples collected in summer/autumn (OR per 10 nmol/L 25(OH)D=0.99, 95% CI 0.93 to 1.06). For blood samples drawn in winter/spring, associations differed significantly between women and men (p=0.004). Among women a positive association was seen (OR per 10 nmol/L 25(OH)D=1.11, 95% CI 1.02 to 1.20), but among men no significant association was observed (OR per 10 nmol/L 25(OH)D=0.90, 95% CI 0.81 to 1.01).

CONCLUSIONS

Overall, no association between vitamin D status and risk of LBP was demonstrated. The association suggested in women for the winter/spring season cannot be regarded as established.