Vitamin D Decreases Beck Depression Inventory Score in Patients with Mild to Moderate Ulcerative Colitis: A Double-Blind Randomized Placebo-Controlled Trial

The effect of vitamin D supplementation on depression: a systematic review and dose-response meta-analysis of randomized controlled trials

The impact of vitamin D supplementation on depressive symptoms remains uncertain. This study aimed to investigate the dose-dependent effects of vitamin D supplementation on depressive and anxiety symptoms in adults. We systematically searched PubMed, Scopus, and Web of Science up to December 2022 to identify randomized controlled trials evaluating the effects of vitamin D3 supplementation on depression and anxiety symptoms in adults. Using a random-effects model, we calculated the standardized mean difference (SMD) for each 1000 IU/day vitamin D3 supplementation. The GRADE tool assessed the certainty of evidence. Our analysis included 31 trials with 24189 participants. Each 1000 IU/day vitamin D3 supplementation slightly reduced depressive symptoms in individuals with and without depression (SMD: -0.32, 95% CI -0.43 to -0.22; GEADE = moderate). The effect was more pronounced in those with depressive symptoms (SMD: -0.57, 95% CI -0.69 to -0.44; n = 15). The greatest reduction occurred at 8000 IU/day (SMD: -2.04, 95% CI -3.77 to -0.31). Trials with follow-up ⩽8 weeks (SMD: -0.45, 95% CI -0.70 to -0.20; n = 8) and 8 to ⩽24 weeks (SMD: -0.47, 95% CI -0.70 to -0.24; n = 15) showed stronger effects compared to those lasting 24 to ⩽52 weeks (SMD: -0.13, 95% CI -0.28 to 0.02; n = 5) or longer than 52 weeks (SMD: 0.14, 95% CI -0.16 to 0.44; n = 3) (p group difference <0.001). Vitamin D3 supplementation had no significant effects on anxiety symptoms. In summary, this study suggests that vitamin D3 supplementation may effectively reduce depressive symptoms in short term. Further high-quality trials are warranted for a conclusive assessment of its impact on anxiety.

Effectiveness of Vitamin D on Neurological and Mental Disorders

(1) Background: Mental disorders are conditions that affect a person's cognition, mood, and behaviour, such as depression, anxiety, bipolar disorder, and schizophrenia. In contrast, neurological disorders are diseases of the brain, spinal cord, and nerves. Such disorders include strokes, epilepsy, Alzheimer's, and Parkinson's. Both mental and neurological disorders pose significant global health challenges, impacting hundreds of millions worldwide. Research suggests that certain vitamins, including vitamin D, may influence the incidence and severity of these disorders; (2) Methods: This systematic review examined the potential effects of vitamin D supplementation on various mental and neurological disorders. Evidence was gathered from databases like PubMed, Cochrane, and Google Scholar, including multiple randomized controlled trials comparing vitamin D supplementation to placebo or no treatment for conditions like depression, bipolar disorder, epilepsy, schizophrenia, and neuroinflammation; (3) Results: The findings strongly indicate that vitamin D supplementation may benefit a range of mental health and neurological disorders. The magnitude of the beneficial impact varied by specific disorder, but the overall pattern strongly supports the therapeutic potential of vitamin D on these disorders; (4) Conclusions: This review provides valuable insight into the role vitamin D may play in the management of critical brain-related health issues.

The role of vitamin D in depression and anxiety disorders: a review of the literature

BACKGROUND

Prevalence of mental health disorders continue to increase worldwide. Over the past decades, suboptimal vitamin D (VD) levels and gut dysbiosis have been associated with neurological dysfunction and psychiatric disorders.

METHODS

In this review, we examined the available literature on VD and mental health disorders, particularly depression and anxiety, in both clinical and pre-clinical studies.

RESULTS

Our extensive review failed to find a link between VD deficiency, depression, and anxiety-related behavior in preclinical animal models. However, strong evidence suggests that VD supplementation may alleviate symptoms in chronically stressed rodents, with some promising evidence from clinical studies. Further, fecal microbiota transplantations suggest a potential role of gut microbiota in neuropsychiatric disorders, although the underlying mechanisms remain to be fully elucidated. It has been postulated that serotonin, primarily produced by gut bacteria, may be a crucial factor. Hence, whether VD has the ability to impact gut microbiota and modulate serotonin synthesis warrants further investigation.

CONCLUSIONS

Taken together, literature has suggested that VD may serve as a key regulator in the gut-brain axis to modulate gut microbiota and alleviate symptoms of depression and anxiety. The inconsistent results of VD supplementation in clinical studies, particularly among VD deficient participants, suggests that current intake recommendations may need to be re-evaluated for individuals at-risk (i.e. prior to diagnosis) of developing depression and/or anxiety.

The use of vitamin D for patients with inflammatory bowel diseases

As vitamin D (VD) plays an essential role in inflammatory bowel diseases (IBD), this systematic review aimed to update the participation of this vitamin in the prevention or remission of these diseases. This review has included studies in MEDLINE-PubMed, EMBASE, and Cochrane databases. The authors have followed PRISMA (Preferred Reporting Items for a Systematic Review and Meta-analysis) guidelines. According to the inclusion and exclusion criteria, twenty-two randomized clinical trials were selected. In total, 1,209 patients were included in this systematic review: 1034 received only VD and 175 received VD in combination with calcium. The average doses of VD supplementation were from oral 400 IU daily to 10,000 IU per kilogram of body weight. Single injection of 300,000 IU of VD was also used. Several studies have shown the crucial role that VD plays in the therapeutic approach of IBD due to its effects on the immune system. It effectively decreased inflammatory cytokines such as TNF-α and IFN-γ (p<0.05) and provided a reduction in disease activity assessed through different scores such as Crohn's Disease Activity Index (CDAI) (p<0.05) and Ulcerative Colitis Disease Activity Index (UCDAI) (p<0.05). Unfortunately, the available clinical trials are not standardized for of doses and routes of administration. Existing meta-analyses are biased because they compare studies using different doses or treatments in combination with different drugs or supplements such as calcium. Even though VD has crucial effects on inflammatory processes, there is still a need for standardized studies to establish how the supplementation should be performed and the doses to be administered.

The correlation between serum 25-hydroxyvitamin D level and ulcerative colitis: a systematic review and meta-analysis

OBJECTIVE

The incidence of UC has increased yearly. Many studies have suggested that patients with ulcerative colitis have abnormal vitamin D levels. A systematic review and meta-analysis were conducted to investigate the association between vitamin D levels and ulcerative colitis.

METHODS

We searched PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, Wanfang and China Science and Technology Journal Database (VIP) from inception to December 2022. We included case-control studies comparing the differences in vitamin D levels between patients with ulcerative colitis and healthy populations. Meta-analysis was performed using Review Manager5.4, Stata17.0 and other software.

RESULTS

Sixteen eligible observational studies were selected from 473 articles involving 2234 subjects, and they included 987 patients with ulcerative colitis and 1247 controls. The results showed that the serum level of vitamin D in patients with ulcerative colitis was significantly lower than that in healthy controls (SMD = -0.83, 95% CI: -1.18, -0.48). Vitamin D deficiency was reported in five studies. The prevalence of vitamin D deficiency was significantly higher in the ulcerative colitis group than in the healthy control group (OR = 1.90, 95% CI: 1.38, 2.62).

CONCLUSION

Serum vitamin D levels were significantly lower in patients with ulcerative colitis than in healthy controls.

The effect of vitamin D supplementation on depressive symptoms in adults: A systematic review and meta-analysis of randomized controlled trials

Neurosteroid and immunological actions of vitamin D may regulate depression-linked physiology. Meta-analyses investigating the effect of vitamin D on depression have been inconsistent. This meta-analysis investigated the efficacy of vitamin D in reducing depressive symptoms among adults in randomized placebo-controlled trials (RCT). General and clinical populations, and studies of ill individuals with systemic diseases were included. Light therapy, co-supplementation (except calcium) and bipolar disorder were exclusionary. Databases Medline, PsycINFO, CINAHL and The Cochrane Library were searched to identify relevant articles in English published before April 2022. Cochrane risk-of-bias tool (RoB 2) and GRADE were used to appraise studies. Forty-one RCTs (n = 53,235) were included. Analyses based on random-effects models were performed with the Comprehensive Meta-analysis Software. Results for main outcome (n = 53,235) revealed a positive effect of vitamin D on depressive symptoms (Hedges' g = -0.317, 95% CI [-0.405, -0.230], p < 0.001, I2 = 88.16%; GRADE: very low certainty). RoB assessment was concerning in most studies. Notwithstanding high heterogeneity, vitamin D supplementation ≥ 2,000 IU/day appears to reduce depressive symptoms. Future research should investigate possible benefits of augmenting standard treatments with vitamin D in clinical depression. PROSPERO registration number: CRD42020149760. Funding: Finnish Medical Foundation, grant 4120 and Juho Vainio Foundation, grant 202100353.

Vitamin D for the treatment of inflammatory bowel disease

BACKGROUND

Vitamin D possesses immunomodulatory properties and has been implicated in the pathogenesis and severity of inflammatory bowel disease (IBD). Animal studies and emerging epidemiological evidence have demonstrated an association between vitamin D deficiency and worse disease activity. However, the role of vitamin D for the treatment of IBD is unclear.

OBJECTIVES

To evaluate the benefits and harms of vitamin D supplementation as a treatment for IBD.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was Jun 2023.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in people of all ages with active or inactive IBD comparing any dose of vitamin D with another dose of vitamin D, another intervention, placebo, or no intervention. We defined doses as: vitamin D (all doses), any-treatment-dose vitamin D (greater than 400 IU/day), high-treatment-dose vitamin D (greater than 1000 IU/day), low-treatment-dose vitamin D (400 IU/day to 1000 IU/day), and supplemental-dose vitamin D (less than 400 IU/day).

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. clinical response for people with active disease, 2. clinical relapse for people in remission, 3. quality of life, and 4. withdrawals due to adverse events. Our secondary outcomes were 5. disease activity at end of study, 6. normalisation of vitamin D levels at end of study, and 7. total serious adverse events. We used GRADE to assess certainty of evidence for each outcome.

MAIN RESULTS

We included 22 RCTs with 1874 participants. Study duration ranged from four to 52 weeks. Ten studies enroled people with Crohn's disease (CD), five enroled people with ulcerative colitis (UC), and seven enroled people with CD and people with UC. Seventeen studies included adults, three included children, and two included both. Four studies enroled people with active disease, six enroled people in remission, and 12 enroled both. We assessed each study for risk of bias across seven individual domains. Five studies were at low risk of bias across all seven domains. Ten studies were at unclear risk of bias in at least one domain but with no areas of high risk of bias. Seven studies were at high risk of bias for blinding of participants and assessors. Vitamin D (all doses) versus placebo or no treatment Thirteen studies compared vitamin D against placebo or no treatment. We could not draw any conclusions on clinical response for UC as the certainty of the evidence was very low (risk ratio (RR) 4.00, 95% confidence interval (CI) 1.51 to 10.57; 1 study, 60 participants). There were no data on CD. There may be fewer clinical relapses for IBD when using vitamin D compared to placebo or no treatment (RR 0.57, 95% CI 0.34 to 0.96; 3 studies, 310 participants). The certainty of the evidence was low. We could not draw any conclusions on quality of life for IBD (standardised mean difference (SMD) -0.13, 95% CI -3.10 to 2.83 (the SMD value indicates a negligent decrease in quality of life, and the corresponding CIs indicate that the effect can range from a large decrease to a large increase in quality of life); 2 studies, 243 participants) or withdrawals due to adverse events for IBD (RR 1.97, 95% CI 0.18 to 21.27; 12 studies, 1251 participants; note 11 studies reported withdrawals but recorded 0 events in both groups. Thus, the RR and CIs were calculated from 1 study rather than 12). The certainty of the evidence was very low. High-treatment-dose vitamin D versus low-treatment-dose vitamin D Five studies compared high treatment vitamin D doses against low treatment vitamin D doses. There were no data on clinical response. There may be no difference in clinical relapse for CD (RR 0.48, 95% CI 0.23 to 1.01; 1 study, 34 participants). The certainty of the evidence was low. We could not draw any conclusions on withdrawals due to adverse events for IBD as the certainty of the evidence was very low (RR 0.89, 95% CI 0.06 to 13.08; 3 studies, 104 participants; note 2 studies reported withdrawals but recorded 0 events in both groups. Thus, the RR and CIs were calculated from 1 study rather than 3). The data on quality of life and disease activity could not be meta-analysed, were of very low certainty, and no conclusions could be drawn. Any-treatment-dose vitamin D versus supplemental-dose vitamin D Four studies compared treatment doses of vitamin D against supplemental doses. There were no data on clinical response and relapse. There were no data on quality of life that could be meta-analysed. We could not draw any conclusions on withdrawals due to adverse events for IBD as the certainty of the evidence was very low (RR 3.09, 95% CI 0.13 to 73.17; 4 studies, 233 participants; note 3 studies reported withdrawals but recorded 0 events in both groups. Thus, the RR and CIs were calculated from 1 study rather than 4).

AUTHORS' CONCLUSIONS

There may be fewer clinical relapses when comparing vitamin D with placebo, but we cannot draw any conclusions on differences in clinical response, quality of life, or withdrawals, due to very low-certainty evidence. When comparing high and low doses of vitamin D, there were no data for clinical response, but there may be no difference in relapse for CD. We cannot draw conclusions on the other outcomes due to very low certainty evidence. Finally, comparing vitamin D (all doses) to supplemental-dose vitamin D, there were no data on clinical relapse or response, and we could not draw conclusions on other outcomes due to very low certainty evidence or missing data. It is difficult to make any clear recommendations for future research on the basis of the findings of this review. Future studies must be clear on the baseline populations, the purpose of vitamin D treatment, and, therefore, study an appropriate dosing strategy. Stakeholders in the field may wish to reach consensus on such issues prior to new studies.

Behavioral abnormalities in C57BL/6 mice with chronic ulcerative colitis induced by DSS

BACKGROUND

Clinical epidemiological studies have found that some patients with ulcerative colitis (UC) are prone to mental disorders. DSS-induced acute and chronic UC models are often used to evaluate the efficacy of anti-UC drugs. However, whether DSS has an effect on mouse behavior has not been reported.

METHODS

Acute and chronic UC models were induced by 3% DSS and 1.5% DSS, respectively. The bloody stool, the changes in the colon length, and histopathological changes in the colon were used to evaluate the success of the animal model. The behavior of mice was evaluated by open field experiment, tail suspension experiment and Sucrose preference test.

RESULTS

The weight of mice in 3% DSS group decreased significantly, the DAI score increased significantly, the colon length of mice was significantly shortened, and the structure of colonic crypts was abnormal, which showed inflammatory cell infiltration and shrinkage of crypts. Compared with the control group, the immobility time of 3%DSS group mice in the tail suspension test and forced swimming test had no effect, the number of running and grooming times was significantly reduced, and there was no significant difference in the number of standing times. No abnormality was observed in HE staining of the hippocampus. However, in 1.5% DSS-induced chronic UC model, behavioral and hippocampal abnormalities were observed not only UC symptoms.

CONCLUSIONS

The acute UC model induced by 3% DSS has certain influence on the behavior of mice, but the mental state of mice is normal, which may be the abnormal behavior caused by UC symptoms; However, the chronic UC model induced by 1.5% DSS has a significant effect on the behavior of mice, and the mice have mental disorders, which are caused by mental disorders.

Molecular Basis Underlying the Therapeutic Potential of Vitamin D for the Treatment of Depression and Anxiety

Major depressive disorder and anxiety disorders are common and disabling conditions that affect millions of people worldwide. Despite being different disorders, symptoms of depression and anxiety frequently overlap in individuals, making them difficult to diagnose and treat adequately. Therefore, compounds capable of exerting beneficial effects against both disorders are of special interest. Noteworthily, vitamin D deficiency has been associated with an increased risk of developing depression and anxiety, and individuals with these psychiatric conditions have low serum levels of this vitamin. Indeed, in the last few years, vitamin D has gained attention for its many functions that go beyond its effects on calcium–phosphorus metabolism. Particularly, antioxidant, anti-inflammatory, pro-neurogenic, and neuromodulatory properties seem to contribute to its antidepressant and anxiolytic effects. Therefore, in this review, we highlight the main mechanisms that may underlie the potential antidepressant and anxiolytic effects of vitamin D. In addition, we discuss preclinical and clinical studies that support the therapeutic potential of this vitamin for the management of these disorders.

Dietary Supplementations and Depression

Depression is a mood disturbance condition that occurs for more than two weeks in a row, leading to suicide. Due to adverse effects of depression, antidepressants and adjunctive therapies, such as dietary supplementation, are used for treatment. Therefore, this review explored and summarized dietary supplements’ types, dosages, and effectiveness in preventing and treating depression. A literature search of the PubMed database was conducted in August 2021 to identify studies assessing depression, after which scale measurements based on dietary supplements were identified. From the obtained 221 studies, we selected 63 papers. Results showed PUFA (EPA and DHA combination), vitamin D, and probiotics as the most common supplementation used in clinical studies to reduce depressive symptoms. We also observed that although the total daily PUFA dosage that exhibited beneficial effects was in the range of 0.7–2 g EPA and 0.4–0.8 g DHA daily, with an administration period of three weeks to four months, positive vitamin D-based supplementation effects were observed after administering doses of 2000 IU/day or 50,000 IU/week between 8 weeks and 24 months. Alternatively, microbes from the genus Lactobacillus and Bifidobacterium in the probiotic group with a minimum dose of 10⁸ CFU in various dose forms effectively treated depression. Besides, a depression scale was helpful to assess the effect of an intervention on depression. Hence, PUFA, vitamin D, and probiotics were proposed as adjunctive therapies for depression treatment based on the results from this study.

The Role of Vitamin D in Immune System and Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a nonspecific inflammatory disease that includes ulcerative colitis (UC) and Crohn’s disease (CD). The pathogenesis of IBD is not fully understood but is most reported associated with immune dysregulation, dysbacteriosis, genetic susceptibility, and environmental risk factors. Vitamin D is an essential nutrient for the human body, and it not only regulates bone metabolism but also the immune system, the intestinal microbiota and barrier. Vitamin D insufficiency is common in IBD patients, and the abnormal low levels of vitamin D are highly correlated with disease activity, treatment response, and risk of relapse of IBD. Accumulating evidence supports the protective role of vitamin D in IBD through regulating the adaptive and innate immunity, maintaining the intestinal barrier and balancing the gut microbiota. This report aims to provide a broad overview of the role vitamin D in the immune system, especially in the pathogenesis and treatment of IBD, and its possible role in predicting relapse.

Is Vitamin D Important in Anxiety or Depression? What Is the Truth?

PURPOSE OF REVIEW

Depression and anxiety are mood disorders that affect health and therefore quality of life and increase the global burden of disease. One of the possible mechanisms in the pathophysiology of these mood disorders has been reported as oxidative stress and inflammation. In the light of this information, it is important to determine the relationship between antioxidant nutrients (such as vitamin D) and these diseases. There are points where the brain regions involved in the pathophysiology of depression and anxiety and vitamin D metabolism intersect.

RECENT FINDINGS

Low vitamin D levels are associated with increased symptoms of depression and anxiety. For this reason, vitamin D screening should be performed in the prevention and treatment planning of these mood disorders. Vitamin D, which has antioxidant properties and activity in brain tissue, is important for mood disorders preventions or treatments but serum levels must be followed.

Adverse health outcomes in vitamin D supplementation trials for depression: A systematic review

BACKGROUND

Vitamin D deficiency is a universal risk factor for adverse health outcomes. Since depression is consistently associated with low vitamin D levels as well as several adverse health outcomes, vitamin D supplementation may be especially relevant for depressed persons. This review examines the potential benefits of vitamin D for (somatic) health outcomes in randomised controlled supplementation trials for depression.

METHOD

Systematic literature search to assess whether adverse health outcomes, such as frailty, falls, or cognitive functioning, were included in vitamin D supplementation trials for depression, and whether these outcomes were affected by supplementation. The revised Cochrane tool for assessing risk of bias in randomised trials was used.

RESULTS

Thirty-one trials were included. Adverse health outcomes were considered in five studies. Two studies reported some beneficial effect on an adverse health outcome.

CONCLUSIONS AND IMPLICATIONS

While depressed persons are at increased risk of vitamin D deficiency, supplementation trials hardly addressed the common negative health consequences of low vitamin D levels as secondary outcome measures. Well-designed trials of the effects of vitamin D supplementation in late-life depression should explore whether adverse health outcomes can be prevented or stabilised, and whether depression benefits from this improvement.

Plasma 25-hydroxyvitamin D levels, quality of life, inflammation and depression in older adults: Are they related?

BACKGROUND AND OBJECTIVES

This study aimed to determine whether there is an association between inflammation and depression taking into account the effect of several confounders, but specially plasma 25-hydroxyvitamin D (25[OH]D) levels.

MATERIAL AND METHODS

A cross-sectional study was conducted on adults (n = 346) aged 60 years or older recruited from primary healthcare centres. Depression was assessed by the Geriatric Depression Scale (GDS), while plasma 25(OH)D and inflammatory cytokines were measured following routine biochemical laboratory protocols.

RESULTS

Subjects were divided into two subgroups according to their depression status, and matched in their baseline conditions using random forest-based propensity scores. Both groups were rather similar in regard to most variables, apart from quality of life (p < 0.001) and plasma levels of IL-6 (p = 0.03). The overall prevalence of vitamin D deficiency was 36.3% (95% Confidence Interval [95% CI], 30.2%-42.5%), without a significant difference between depression groups (p = 0.2). A significant association was observed between GDS score and plasma IL-6 levels only among those with SF-6D score between 0.26 and 0.50 (p = 0.001).

CONCLUSIONS

The association between inflammation and depression is more likely to be due to a moderation influence of quality of life rather than plasma 25(OH)D levels. However, further studies are needed to ascertain the effect of a poor quality of life leading to chronic inflammation and poor health upon longer periods of follow-up.

Effects of vitamin D supplementation on blood markers in ulcerative colitis patients: a systematic review and meta-analysis

OBJECTIVE

Observational studies have shown that vitamin D levels are inversely related to ulcerative colitis activity, yet evidence from population interventions remains inconsistent. We conducted a systematic review and meta-analysis of randomized-controlled trials to clarify the effect of vitamin D on blood markers in patients with ulcerative colitis.

METHODS

The PubMed, Cochrane Library, Embase, CNKI, VIP, and Wanfang databases were searched for studies published before June 2020. Information was collected regarding serum vitamin D levels, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP), and Ca (calcium), and parathyroid hormone (PTH), and ulcerative colitis disease activity index (UCDAI) research data.

RESULTS

Seven studies (n = 539) were included in the meta-analysis. Vitamin D supplementation resulted in significant improvements in the serum vitamin D levels (standardized mean difference (SMD) = 0.69, 95% CI (0.36, 1.03), P < 0.001), ESR (weighted mean difference (WMD) = - 1.10, 95% CI (- 1.97, - 0.24), P = 0.01), CRP (SMD = - 0.43, 95% CI (- 0.67, - 0.20), P = 0.0003), and Ca (SMD = 0.92, 95% CI (0.09, 1.74), P = 0.03) but not in other outcomes. According to subgroup analysis, supplementation with vitamin D at a dose of ≥ 300,000 IU/day can improve serum vitamin D levels. Supplementation with a sufficient dose of vitamin D in a short period of time can also improve serum vitamin D levels. According to GRADE method evaluation, the evidence quality was classified as low for the Serum Vitamin D Level and ESR, and very low for the CRP, PTH, Ca, and UCDAI.

CONCLUSIONS

Compared with placebo control interventions, vitamin D supplementation seemed to be an effective intervention for patients with ulcerative colitis. Different doses of vitamin D and durations of intervention produce different effects. However, due to the limitation of the quality of the included studies, the above conclusions still need to be verified by more high-quality studies and weak clinical recommendations.

Vitamin D in Inflammatory Bowel Disease: Biological, Clinical and Therapeutic Aspects

BACKGROUND

Vitamin D has an immunoregulatory action in Inflammatory Bowel Disease (IBD) as well as other immune-mediated disorders. Its influence on intestinal permeability, innate and adaptive immunity, and the composition and diversity of the microbiota contribute to the maintenance of intestinal homeostasis. Patients with IBD have a greater prevalence of vitamin D deficiency than the general population, and a possible association between this deficit and a worse course of the disease. However, intervention studies in patients with IBD have proved inconclusive.

OBJECTIVE

To review all the evidence concerning the role of vitamin D as an important factor in the pathophysiology of IBD, review the associations found between its deficiency and the prognosis of the disease, and draw conclusions for the practical application from the main intervention studies undertaken.

METHODS

Structured search and review of basic, epidemiological, clinical and intervention studies evaluating the influence of vitamin D in IBD, following the basic principles of scientific data.

RESULTS

Vitamin D deficiency is associated with disease activity, quality of life, the consumption of social and healthcare resources, and the durability of anti-TNFα biological treatment. Determination of new metabolites of vitamin D, measurement of its absorption capacity and questionnaires about sun exposure could help identify groups of IBD patients with a special risk of vitamin D deficiency.

CONCLUSION

Well-designed intervention studies are needed in IBD, with probably higher objective plasma doses of vitamin D to establish its efficacy as a therapeutic agent with immunomodulatory properties. Meanwhile, vitamin D deficiency should be screened for and corrected in affected patients in order to achieve adequate bone and phosphocalcic metabolism.

Potential Role of Vitamin D for the Management of Depression and Anxiety

Vitamin D, a fat-soluble vitamin, plays a role not only in calcium and phosphate homeostasis but also in several other functions, including cell growth and neuromuscular and immune function. The deficiency of vitamin D is highly prevalent throughout the world and has been suggested to be associated with an enhanced risk of major depressive disorder (MDD) and anxiety disorders. Therefore, vitamin D supplementation has been investigated for the prevention and treatment of these disorders. This review presents preclinical and clinical evidence of the effects of vitamin D supplementation in these disorders. Although preclinical studies provide limited evidence on the possible mechanisms underlying the beneficial effects of vitamin D for the management of these disorders, most of the clinical studies have indicated that vitamin D supplementation is associated with the reduction of symptoms of depression and anxiety, particularly when the supplementation was carried out in individuals with an MDD diagnosis (of the 13 studies in which MDD diagnosis was established, 12 had positive results with vitamin supplementation). However, some heterogeneity in the outcomes was observed and might be associated with an absence of overt psychiatric symptoms in several studies, genetic polymorphisms that alter vitamin D metabolism and bioavailability, differences in the supplementation regimen (monotherapy, adjunctive therapy, or large bolus dosing), and levels of 25-hydroxyvitamin D₃ (25(OH)D) at baseline (individuals with low vitamin D status may respond better) and attained after supplementation. Additionally, factors such as sex, age, and symptom severity also need to be further explored in relation to the effects of vitamin D. Therefore, although vitamin D may hold significant potential for mental health, further preclinical and clinical studies are clearly necessary to better understand its role on mood/affect modulation.