Monthly vitamin D supplementation, pain, and pattern of analgesic prescription: secondary analysis from the randomized, double-blind, placebo-controlled Vitamin D Assessment study

Vitamin D, chronic pain, and depression: linear and non-linear Mendelian randomization analyses

Vitamin D deficiency has been linked to various chronic pain conditions. However, randomized trials of vitamin D supplementation have had mixed results. In contrast, systematic reviews of randomized trials indicate a protective effect of vitamin D supplementation on depression. We undertake a Mendelian randomization investigation in UK Biobank, a study of UK residents aged 40-65 at recruitment. We perform linear and non-linear Mendelian randomization analyses for four outcomes: fibromyalgia, clinical fatigue, chronic widespread pain, and probable lifetime major depression. We use genetic variants from four gene regions with known links to vitamin D biology as instruments. In linear analyses, genetically-predicted levels of 25-hydroxyvitamin D [25(OH)D], a clinical marker of vitamin D status, were not associated with fibromyalgia (odds ratio [OR] per 10 nmol/L higher 25(OH)D 1.02, 95% confidence interval [CI] 0.93, 1.12), clinical fatigue (OR 0.99, 95% CI 0.94, 1.05), chronic widespread pain (OR 0.95, 95% CI 0.89, 1.02), or probable lifetime major depression (OR 0.97, 95% CI 0.93, 1.01). In non-linear analyses, an association was observed between genetically-predicted 25(OH)D levels and depression in the quintile of the population with the lowest 25(OH)D levels (OR 0.75, 95% CI 0.59, 0.94); associations were null in other strata. Our findings suggest that population-wide vitamin D supplementation will not substantially reduce pain or depression; however, targeted supplementation of deficient individuals may reduce risk of depression.

Associations of vitamin D status with all-cause and cause-specific mortality in long-term prescription opioid users

Objective

This study aimed to investigate the association between serum 25-hydroxyvitamin D (25(OH)D) concentrations and mortality in long-term prescription opioid users.

Methods

The study included 1856 long-term prescription opioid users from the National Health and Nutrition Examination Survey (NHANES, 2001-2018). Mortality status were determined by matching with the National Death Index (NDI) records until December 31, 2019. Multivariable Cox proportional hazard models were constructed to assess the association.

Results

Over a median follow-up period of 7.75 years, there were 443 cases of all-cause mortality, including 135 cardiovascular disease (CVD) deaths and 94 cancer deaths. After multivariable adjustment, participants with serum 25(OH)D concentrations within 50.00 to <75.00 nmol/L and ≥ 75 nmol/L had a lower risk of all-cause mortality, with hazard ratios (HRs) of 0.50 (95% confidence interval [CI] 0.29, 0.86) and 0.54 (95% CI 0.32, 0.90), respectively. Nevertheless, no significant association was found between serum 25(OH)D concentrations and the risk of CVD or cancer mortality. The RCS analysis revealed a non-linear association of serum 25(OH)D concentration with all-cause mortality (p for non-linear = 0.01). Per 1-unit increment in those with serum 25(OH)D concentrations <62.17 nmol/L corresponded to a 2% reduction in the risk of all-cause mortality (95% CI 0.97, 1.00), but not changed significantly when 25(OH)D concentrations ≥62.17 nmol/L.

Conclusion

In conclusion, a non-linear association existed between serum 25(OH)D concentrations and all-cause mortality in long-term prescription opioid users. Maintaining serum 25(OH)D concentrations ≥62.17 nmol/L may be beneficial in preventing all-cause mortality in this population.

The effect of vitamin D and omega-3 fatty acid supplementation on pain prevalence and severity in older adults: a large-scale ancillary study of the VITamin D and OmegA-3 triaL (VITAL)

ABSTRACT

A diet supplemented with vitamin D and marine omega-3 fatty acids may prevent and treat painful disorders by promoting the resolution of inflammation. However, large, randomized placebo-controlled trials evaluating the effects of supplementation with omega-3 fatty acids and vitamin D on the presence and severity of pain are lacking. VITamin D and OmegA-3 triaL-Pain (VITAL-Pain) is an ancillary study to the VITAL trial, a large randomized, double-blind, placebo-controlled trial of vitamin D (2000 IU/day) and omega-3 supplementation (1 g/day) over 5.3 years of median follow-up, among 25,871 older men and women. We assessed pain among those reaching the end of the VITAL intervention phase using questions from the 2012 National Health Interview Survey. We used ordinal logistic regression to test the effect of vitamin D and omega-3 fatty acids on the odds ratio (OR) and 95% confidence interval [CI] of reporting higher pain prevalence or severity. Overall, 19,611 participants provided complete pain information at the end of the VITAL trial. The ORs for higher pain prevalence or severity for vitamin D and omega-3 supplementation vs placebo were 0.99 ([CI] 0.94-1.05) and 0.99 ([CI] 0.94-1.04), respectively. There was no interaction between the 2 active treatments. Dietary supplementation with commonly used moderate doses of vitamin D or omega-3 fatty acids over a median of 5.3 years did not result in a lower prevalence or severity of pain in middle-aged and older U.S. adults.

The Efficacy of Vitamin D Supplementation in the Treatment of Fibromyalgia Syndrome and Chronic Musculoskeletal Pain

Fibromyalgia syndrome (FMS) and chronic widespread musculoskeletal pain (CMP) are diffuse suffering syndromes that interfere with normal activities. Controversy exists over the role of vitamin D in the treatment of these diseases. We carried out a systematic literature review of randomized controlled trials (RCT) to establish whether vitamin D (25OHD) deficiency is more prevalent in CMP patients and to assess the effects of vitamin D supplementation in pain management in these individuals. We searched PubMed, Physiotherapy Evidence Database (PEDro), and the Cochrane Central Register of Controlled Trials (CENTRAL) for RCTs published in English from 1 January 1990 to 10 July 2022. A total of 434 studies were accessed, of which 14 satisfied the eligibility criteria. In our review three studies, of which two had the best-quality evidence, a correlation between diffuse muscle pain and 25OHD deficiency was confirmed. Six studies, of which four had the best-quality evidence, demonstrated that appropriate supplementation may have beneficial effects in patients with established blood 25OHD deficiency. Eight studies, of which six had the best-quality evidence, demonstrated that 25OHD supplementation results in pain reduction. Our results suggest a possible role of vitamin D supplementation in alleviating the pain associated with FMS and CMP, especially in vitamin D-deficient individuals.

Non-drug pain relievers active on non-opioid pain mechanisms

This review is aimed to summarize the pain-relieving effect of non-drug substances, mostly prescribed as integrators in treatment of pain, including especially in chronic postoperative pain (CPSP) and in chronic back pain after acute episodes. Their use reflects the fact that the current treatments for these syndromes continue to pose problems of unsatisfactory responses in a significant portion of patients and/or of an excess of side effects like those noted in the present opioid crisis. As integrators are frequently introduced into the market without adequate clinical testing, this review is aimed to collect the present scientific evidence either preclinical or clinical for their effectiveness. In particular, we reviewed the data on the use of: B vitamins; vitamin C; vitamin D; alpha lipoic acid (ALA); N-acetylcysteine; acetyl L-carnitine; curcumin; boswellia serrata; magnesium; coenzyme Q10, and palmitoylethanolamide. The combination of preclinical findings and clinical observations strongly indicate that these compounds deserve more careful attention, some of them having interesting clinical potentials also in preventing chronic pain after an acute episode. In particular, examining their putative mechanisms of action it emerges that combinations of few of them may exert an extraordinary spectrum of activities on a large variety of pain-associated pathways and may be eventually used in combination with more traditional pain killers in order to extend the duration of the effect and to lower the doses. Convincing examples of effective combinations against pain are vitamin B complex plus gabapentin for CPSP, including neuropathic pain; vitamin B complex plus diclofenac against low back pain and also in association with gabapentin, and ALA for burning mouth syndrome. These as well as other examples need, however, careful controlled independent clinical studies confirming their role in therapy.

Effects of Vitamin D Supplementation on Disabling Foot Pain in Patients With Symptomatic Knee Osteoarthritis

OBJECTIVE

The present study was undertaken to determine whether vitamin D supplementation or maintaining sufficient vitamin D level reduces foot pain over 2 years in patients with symptomatic knee osteoarthritis (OA).

METHODS

A post hoc study was conducted from a randomized, double-blind, placebo-controlled trial named the Vitamin D Effect on Osteoarthritis (VIDEO) study. Symptomatic knee OA patients with serum 25-hydroxyvitamin D levels between 12.5 nmoles/liter and 60 nmoles/liter were included and randomly allocated to either monthly vitamin D₃ or placebo treatment (1:1) for 2 years. Manchester Foot Pain and Disability Index (MFPDI) was used to evaluate foot pain and disabling foot pain was defined as at least 1 of the 10 functional limitation items (items 1-9 and 11) being documented as on "most/every day(s)" in the last month. A repeated-measures, mixed-effects model was used to analyze the change of MFPDI scores between groups adjusting for potential confounders.

RESULTS

A total of 413 patients with a mean age of 63.2 years (49.7% males) were enrolled and 340 completed the study. The mean MFPDI score was 22.8 ± 7.3, with 23.7% of participants having disabling foot pain at baseline. There were significant differences in MFPDI scores change between groups over 2 years, with more improvements in the vitamin D group than in the placebo group (-0.03 versus 1.30; P = 0.013) and more improvement in those maintaining sufficient vitamin D levels (n = 226) than those who did not (n = 114) (-0.09 versus 2.19; P = 0.001).

CONCLUSION

Vitamin D supplementation and maintenance of sufficient vitamin D levels may improve foot pain in those with knee OA.

'Palliative-D'-Vitamin D Supplementation to Palliative Cancer Patients: A Double Blind, Randomized Placebo-Controlled Multicenter Trial

Simple Summary

In this study, the effect of vitamin D supplementation on pain, infections, fatigue and quality of life in patients with advanced cancer with verified vitamin D deficiency was studied. To this end, a randomized controlled trial, ‘Palliative-D’, was conducted, comparing the effect of 4000 IU vitamin D₃/day for 12 weeks to placebo in cancer patients admitted to palliative care. Pain was assessed as change in opioid dose and infections measured as days on antibiotics. Vitamin D-supplemented patients increased their opioid doses at a significantly slower rate than patients receiving placebo, i.e., 0.56 µg less fentanyl/h per week with vitamin D treatment. Vitamin D reduced self-assessed fatigue but did not affect antibiotic use or self-assessed Quality of life. The treatment was safe and well-tolerated. In conclusion, correction of vitamin D deficiency may have positive effects on pain and fatigue in palliative cancer patients.

Abstract

The aim of the ‘Palliative-D’ study was to test the hypothesis that correction of vitamin D deficiency reduces opioid use in cancer patients admitted to palliative care. A multicenter randomized, placebo-controlled, double-blind trial in three home-based palliative care facilities in Sweden was performed. Patients with advanced cancer and 25-hydroxyvitamin D < 50 nmol/L were randomized to vitamin D3 4000 IU/day or placebo for 12 weeks. The primary endpoint was the difference of long-acting opioid use (fentanyl ug/h) between the groups during 12 weeks, based on four time points. Secondary outcomes included changes in antibiotic use, fatigue and Quality of Life (QoL). A total of 244 patients were randomized, and 150 patients completed the 12 weeks. The major reason for drop-out was death due to cancer. The vitamin D-group had a significantly smaller increase of opioid doses compared to the placebo-group; beta coefficient −0.56 (p = 0.03), i.e., 0.56 µg less fentanyl/h per week with vitamin D treatment. Vitamin D-reduced fatigue assessed with ESAS was −1.1 points after 12 weeks (p < 0.01). Antibiotic use or QoL did not differ significantly between the groups. The treatment was safe and well-tolerated. In conclusion, correction of vitamin D deficiency may have positive effects on opioid use and fatigue in palliative cancer patients, but only in those with a survival time more than 12 weeks.

Is There Proof of Extraskeletal Benefits From Vitamin D Supplementation From Recent Mega Trials of Vitamin D?

Scientific interest in possible extraskeletal effects of vitamin D first appeared in the 1930s soon after the structure of vitamin D was characterized, and increased in the 1980s with the development of assays of 25-hydroxyvitamin D status as a marker of vitamin D status, which in observational epidemiological studies was shown to be inversely associated with many nonskeletal diseases. This resulted in the start of seven large randomized controlled trials (n > 2000 participants in each) of vitamin D supplementation giving higher doses than previously used. The intervention periods in these trials collectively started in 2009 and continued to 2020. They have recruited participants, mostly of both sexes and over the age of 50 years, from many countries and have given either daily or monthly doses of vitamin D. Collectively, the trials have a wide range of outcomes with the main focus on the prevention of cancer, cardiovascular disease, and fractures, besides many other outcomes. The findings of four trials have been published, and they have shown that vitamin D supplementation does not prevent hard-disease endpoints, such as cardiovascular disease, cancer, fractures, or falls, aside from a possible beneficial effect against cancer mortality. In contrast, beneficial effects were seen for intermediate outcomes such as BMD of spine and hips, arterial function, and lung function, especially in people with vitamin D deficiency. The finding of a benefit primarily in people with vitamin D deficiency, if confirmed by the other trials, would support a population approach to preventing vitamin D deficiency using fortification rather than the high-risk approach of screening for deficiency combined with supplementation. The findings on other outcomes from the three published trials, along with the findings from the four unpublished trials, are expected within the next 2 to 3 years to clarify the role of vitamin D supplementation in preventing nonskeletal disease. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Controversies in Vitamin D: A Statement From the Third International Conference

The Third International Conference on Controversies in Vitamin D was held in Gubbio, Italy, September 10–13, 2019. The conference was held as a follow‐up to previous meetings held in 2017 and 2018 to address topics of controversy in vitamin D research. The specific topics were selected by the steering committee of the conference and based upon areas that remain controversial from the preceding conferences. Other topics were selected anew that reflect specific topics that have surfaced since the last international conference. Consensus was achieved after formal presentations and open discussions among experts. As will be detailed in this article, consensus was achieved with regard to the following: the importance and prevalence of nutritional rickets, amounts of vitamin D that are typically generated by sun exposure, worldwide prevalence of vitamin D deficiency, the importance of circulating concentrations of 25OHD as the best index of vitamin D stores, definitions and thresholds of vitamin D deficiency, and efficacy of vitamin D analogues in the treatment of psoriasis. Areas of uncertainly and controversy include the following: daily doses of vitamin D needed to maintain a normal level of 25OHD in the general population, recommendations for supplementation in patients with metabolic bone diseases, cutaneous production of vitamin D by UVB exposure, hepatic regulation of 25OHD metabolites, definition of vitamin D excess, vitamin D deficiency in acute illness, vitamin D requirements during reproduction, potential for a broad spectrum of cellular and organ activities under the influence of the vitamin D receptor, and potential links between vitamin D and major human diseases. With specific regard to the latter area, the proceedings of the conference led to recommendations for areas in need of further investigation through appropriately designed intervention trials. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

The Vitamin D Assessment (ViDA) study - Design and main findings

Accumulating evidence from observational studies indicates that vitamin D status is inversely associated with a many non-skeletal diseases. This has initiated the conduct of several large clinical trials to determine if high dose vitamin D supplementation (≥ 2000 IU/day or monthly equivalent) prevents non-skeletal disease including cardiovascular disease, cancer and mortality. One of these trials is the Vitamin D Assessment (ViDA) Study which recruited 5110 participants, aged 50-84 years, mostly from primary care practices in Auckland, New Zealand. The intervention was a capsule that contained either 100,000 IU vitamin D3 or placebo, two of which were taken by each participant soon after randomization, and then monthly up to 31 July 2015 (median follow-up 3.3 years). Information on study outcomes came from self-completed questionnaires and health data collected routinely by the Ministry of Health. There was no effect of vitamin D on the main outcomes: cardiovascular disease, acute respiratory infections, non-vertebral fractures, falls and all cancer. In contrast, vitamin D increased persistence with taking statins among participants on long term statin therapy. Beneficial effects were seen also for lung function among ever smokers (especially if vitamin D deficient), and in participants with low 25-hydroxyvitamin D levels for bone mineral density and arterial function. The findings support future research being carried out mainly in people who are vitamin D deficient, although there are practical and ethical issues in recruiting such people into future vitamin D supplementation trials.

Overview of results from the Vitamin D Assessment (ViDA) study

BACKGROUND

The Vitamin D Assessment (ViDA) study is a randomised, double-blind, placebo-controlled trial to evaluate the efficacy of monthly vitamin D supplementation in reducing the incidence of a range of acute and chronic diseases and intermediate outcomes.

METHODS

The study was carried out in Auckland, New Zealand, among 5110 adults, aged 50-84 years, who were followed for a median 3.3 years. The intervention was vitamin D3 (2.5 mg or 100,000 IU) or placebo softgel oral capsules, mailed monthly to participants' homes, with two capsules sent in the first mail-out post-randomisation (i.e. 200,000 IU bolus, or placebo), followed 1 month later (and thereafter monthly) with 100,000 IU vitamin D3 or placebo capsules. Outcomes were monitored through routinely collected health data and self-completed questionnaires.

RESULTS

The results showed no beneficial effect of vitamin D supplementation on incidence of cardiovascular disease, falls, non-vertebral fractures and all cancer. However, beneficial effects from vitamin D supplementation were seen: for persistence with taking statins in participants on long-term statin therapy; and also in bone mineral density and arterial function in participants with low 25-hydroxyvitamin D levels, and in lung function among ever smokers (especially if vitamin D deficient). The latter findings are consistent with several previous studies, CONCLUSION: Monthly high-dose vitamin D supplementation does not prevent a range of diseases, but may be beneficial for some intermediate outcomes in people who are vitamin D deficient.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry identifier: ACTRN12611000402943.

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.