Effect of calcium and vitamin D supplementation on bone mineral density in children with inflammatory bowel disease

Osteoporosis and Bone Fragility in Children: Diagnostic and Treatment Strategies

The incidence of osteoporosis in children is increasing because of the increased survival rate of children with chronic diseases and the increased use of bone-damaging drugs. As childhood bone fragility has several etiologies, its management requires a thorough evaluation of all potentially contributing pathogenetic mechanisms. This review focuses on the main causes of primary and secondary osteoporosis and on the benefits and limits of the different radiological methods currently used in clinical practice for the study of bone quality. The therapeutic and preventive strategies currently available and the most novel diagnostic and treatment strategies are also presented. Optimal management of underlying systemic conditions is key for the treatment of bone fragility in childhood. DXA still represents the gold standard for the radiologic evaluation of bone health in children, although other imaging techniques such as computed tomography and ultrasound evaluations, as well as REMS, are increasingly studied and used. Bisphosphonate therapy is the gold standard for pharmacological treatment in both primary and secondary pediatric osteoporosis. Evidence and experience are building up relative to the use of monoclonal antibodies such as denosumab in cases of poor response to bisphosphonates in specific conditions such as osteogenesis imperfecta, juvenile Paget's disease and in some cases of secondary osteoporosis. Lifestyle interventions including adequate nutrition with adequate calcium and vitamin D intake, as well as physical activity, are recommended for prevention.

Bone health in inflammatory bowel disease

INTRODUCTION

Inflammatory bowel disease (IBD) is a chronic disease characterized by the presence of systemic inflammation, manifesting not only as gastrointestinal symptoms but also as extraintestinal bone complications, including osteopenia and osteoporosis. However, the association between IBD and osteoporosis is complex, and the presence of multifactorial participants in the development of osteoporosis is increasingly recognized. Unlike in adults, delayed puberty and growth hormone/insulin-like growth factor-1 axis abnormalities are essential risk factors for osteoporosis in pediatric patients with IBD.

AREAS COVERED

This article reviews the potential pathophysiological mechanisms contributing to osteoporosis in adult and pediatric patients with IBD and provides evidence for effective prevention and treatment, focusing on pediatric patients with IBD. A search was performed from PubMed and Web of Science inception to February 2023 to identify articles on IBD, osteoporosis, pediatric, and fracture risk.

EXPERT OPINION

A comprehensive treatment pattern based on individualized principles can be used to manage pediatric IBD-related osteoporosis.

The Prevalence of Iron and Vitamin D Deficiencies in Pediatric Patients With Inflammatory Bowel Disease in Bahrain

Introduction Inflammatory bowel diseases (IBD) are chronic diseases that can affect nutrient absorption leading to micronutrient deficiencies and biochemical abnormalities.This study aimed to assess certain serum micronutrients and nutritionally related biochemical markers levels in patients with pediatric IBD and to compare the actual levels and the prevalence of micronutrients deficiencies and biochemical abnormalities between patients with Crohn's disease (CD) and those with ulcerative colitis (UC). Methods A retrospective cross-sectional study reviewing medical records of patients with IBD was conducted in the pediatric department, Salmaniya medical complex, Bahrain, from 1 January 1984 to 31 December 2021. Demographic data and laboratory results related to micronutrients and biochemical markers including full blood count, total protein, albumin, globulin, iron, ferritin, folic acid, vitamin B12, calcium, phosphorous, magnesium, and vitamin D levels were collected upon presentation before starting the treatment. Nutritional deficiencies were compared based on sex, nationality, type of IBD, age at presentation, disease duration, weight at diagnosis, and inflammatory markers levels including erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). Results Of 157 patients with pediatric IBD, 117 (74.5%) were included. Sixty-six (56.4%) patients were males. Sixty-six (56.4%) had CD and 51 (43.6%) had UC. No patient had indeterminant colitis. The mean age at presentation was 10.8±3.8 years. Most patients had one or more micronutrient deficiencies (n=110, 94%). Anemia was a common finding (n=79/116, 68.1%), with iron deficiency anemia (IDA) being predominant. Low iron levels were noted in 64/77 (83.1%) patients with a median of 5.0 (2.0-9.3) µmol/L (normal range, 11.6-31.3); isolated iron deficiency (ID) in 11/18 (61.1%) and IDA in 53/59 (89.8%) patients. Vitamin D deficiency was the second most common (n=45/61, 73.8%). Serum albumin, ferritin, calcium, phosphorous, and magnesium were deficient in 29.2%, 27.8%, 31.7%, 12.5%, and 10%, respectively. One patient had vitamin B12 deficiency while none had folate deficiency. Patients with CD had significantly lower serum iron (5.4±5.6 versus 8.1±6.09 µmol//L, p=0.02) and lower serum protein (71.7±8.7 versus 75.4±9.9 g/L, p=0.043) but higher serum ferritin (45 (19-110.2) versus 21.3 (10.3-51.2) µg/L, p=0.046) compared to those with UC. Elevated ESR was noted in 62/105 (59.1%) patients while high CRP was found in 67/104 (64.4%). Patients with low iron had higher ESR (28 (17-47) versus 14 (10-33) mm/h, p=0.028) and higher CRP (13.3 (1.6-42) versus 1.8 (0.9-4.6) mg/L, p=0.019) levels compared to those with normal levels. Conclusion Patients with pediatric IBD are at risk of multiple micronutrient deficiencies and biochemical abnormalities. Iron and vitamin D deficiencies are the most frequent. Patients with CD are more prone to have lower serum iron and protein levels than those with UC. ID was associated with elevated inflammatory markers.

Vitamin D therapy in pediatric patients with inflammatory bowel disease: a systematic review and meta-analysis

BACKGROUND

There is some evidence for the role of vitamin D deficiency in the pathogenesis of inflammatory bowel disease (IBD) in the pediatric population. However, the results are contradictory. Therefore, we have conducted a systematic review and meta-analysis to evaluated the effect of vitamin D on pediatric patients with IBD.

METHODS

We carried out a systematic search in databases from inception until 20 January 2022. We included all relevant articles that evaluate the efficacy and safety of vitamin D on disease activity, inflammatory factors, and vitamin D and calcium levels in pediatric patients with IBD. Random effects models were used to combine the data. The main outcomes were then analyzed using weight mean difference (WMD) and respective 95% confidence interval (CI).

RESULTS

Fifteen treatment arms met the eligibility criteria and were included. Pooled estimates indicated that intervention with vitamin D has a significantly beneficial effect on 25-hydroxyvitamin D3 [25(OH) D3] (pooled WMD of 17.662 ng/mL; CI 9.77-25.46; P < 0.001), calcium (pooled WMD of 0.17 mg/dL; CI 0.04-0.30; P = 0.009), and inflammatory factors including C-reactive protein (CRP) (pooled WMD of -6.57 mg/L; CI -11.47 to -1.67; P = 0.009) and erythrocyte sedimentation rate (ESR) (pooled WMD of -7.94 mm/h; CI -12.65 to -3.22; P = 0.001) levels. In addition, this effect was greater for vitamin D levels at doses greater than 2000 IU, and when follow-up duration was more than 12 weeks.

CONCLUSION

This study showed that vitamin D therapy can have a significant and beneficial effect on 25(OH) D3, calcium, and inflammatory factors in children and adolescents with IBD.

Relevance of Biotin Deficiency in Patients with Inflammatory Bowel Disease and Utility of Serum 3 Hydroxyisovaleryl Carnitine as a Practical Everyday Marker

Background: Biotin, a water-soluble B vitamin, has demonstrable anti-inflammatory properties. A biotin-deficient diet induced a colitis-like phenotype in mice, alleviable by biotin substitution. Mice with dextran sulfate sodium (DSS)-induced colitis showed biotin deficiency and diminished levels of sodium-dependent multivitamin transporter, a protein involved in biotin absorption. Biotin substitution induced remission by reducing activation of NF-κB, a transcription factor involved in intestinal permeability and inflammatory bowel disease (IBD). We investigated for the first time a possible clinical role of biotin status in IBD. Methods: In a comparative, retrospective, cross-sectional study, serum samples of 138 patients with IBD (67 female; 72 Crohn’s disease (CD), 66 ulcerative colitis (UC)) aged 18–65 years and with a mean age (±SD) of 42.5 ± 14.3 years as well as 80 healthy blood donors (40 female; 40.0 ± 10.0 years; range 20–60 years) were analyzed. Inflammation was defined as hsCRP ≥5 mg/L, and to determine biotin status, serum 3-hydroxyisovaleryl carnitine (3HIVc) levels were measured by LC-MS/MS. Results: A total of 138 patients with IBD (67f; 72CD/66 UC; 42.5 ± 14.3 years) were enrolled: 83/138 had inflammation. Mean serum 3HIVc levels were significantly higher in IBD patients but unaffected by inflammation. Biotin deficiency (95th percentile of controls: >30 nmol/L 3HIVc) was significantly more common in IBD patients versus controls. Conclusion: High serum 3HIVc levels and biotin deficiency were associated with IBD but not inflammatory activity or disease type. Our findings suggest biotin may play a role as cause or effect in IBD pathogenesis. Routine assessment and supplementation of biotin may ameliorate IBD and support intestinal integrity.

Bone loss in patients with inflammatory bowel disease: cause, detection and treatment

PURPOSE OF REVIEW

Inflammatory bowel disease (IBD) is associated with bone loss leading to osteoporosis and increased fracture risk. Bone loss is the result of changes in the balanced process of bone remodeling. Immune cells and cytokines play an important role in the process of bone remodeling and it is therefore not surprising that cytokines as observed in IBD are involved in bone pathology. This review discusses the role of cytokines in IBD-associated bone loss, including the consequences for treatment.

RECENT FINDINGS

Many studies have been conducted that showed the effect of a single cytokine on bone cells in vitro, including interleukin (IL)-1β, IL-6, IL-8, IL-12/IL-23, IL-17, IL-18, IL-32 and interferon-γ. Recently new members of the IL-1 family (IL-1F) have been related to IBD but the consequences for bone health remain uncertain.

SUMMARY

Overall, patients have to deal with a cocktail of cytokines, present in their serum. The combination of cytokines can affect bone cells differently compared to the effects of a single cytokine. This implicates that treatment, focused on reducing the inflammation could work best for bone health as well. Vitamin D might also play a role in this.

Glucocorticoid-Induced Osteoporosis: Why Kids Are Different

Glucocorticoids (GC) are an important risk factor for bone fragility in children with serious illnesses, largely due to their direct adverse effects on skeletal metabolism. To better appreciate the natural history of fractures in this setting, over a decade ago the Canadian STeroid-associated Osteoporosis in the Pediatric Population ("STOPP") Consortium launched a 6 year, multi-center observational cohort study in GC-treated children. This study unveiled numerous key clinical-biological principles about GC-induced osteoporosis (GIO), many of which are unique to the growing skeleton. This was important, because most GIO recommendations to date have been guided by adult studies, and therefore do not acknowledge the pediatric-specific principles that inform monitoring, diagnosis and treatment strategies in the young. Some of the most informative observations from the STOPP study were that vertebral fractures are the hallmark of pediatric GIO, they occur early in the GC treatment course, and they are frequently asymptomatic (thereby undetected in the absence of routine monitoring). At the same time, some children have the unique, growth-mediated ability to restore normal vertebral body dimensions following vertebral fractures. This is an important index of recovery, since spontaneous vertebral body reshaping may preclude the need for osteoporosis therapy. Furthermore, we now better understand that children with poor growth, older children with less residual growth potential, and children with ongoing bone health threats have less potential for vertebral body reshaping following spine fractures, which can result in permanent vertebral deformity if treatment is not initiated in a timely fashion. Therefore, pediatric GIO management is now predicated upon early identification of vertebral fractures in those at risk, and timely intervention when there is limited potential for spontaneous recovery. A single, low-trauma long bone fracture can also signal an osteoporotic event, and a need for treatment. Intravenous bisphosphonates are currently the recommended therapy for pediatric GC-induced bone fragility, typically prescribed to children with limited potential for medication-unassisted recovery. It is recognized, however, that even early identification of bone fragility, combined with timely introduction of intravenous bisphosphonate therapy, may not completely rescue the osteoporosis in those with the most aggressive forms, opening the door to novel strategies.

The role of vitamin D in inflammatory bowel disease: a guide for clinical practice

INTRODUCTION

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract that carries significant morbidity and mortality. Given the need to identify modifiable risk factors to prevent IBD development and to mitigate disease severity, vitamin D has become a major candidate of interest.

AREAS COVERED

In this review, we discuss the regulatory role played by vitamin D in intestinal immune homeostasis, updates in the recent literature exploring its role in de novo IBD pathogenesis and established IBD activity. We also discuss societal recommendations on its therapeutic role in maintaining bone health and future directions for studying its role in regulating disease activity.

EXPERT OPINION

In contrast to findings from earlier studies suggesting a causal role in IBD, recent findings indicate that vitamin D deficiency may be a sequela rather than a cause of IBD. Additionally, clinical trials exploring vitamin D therapy in reducing disease activity remain inconclusive thus far, with the current evidence best supporting a therapeutic role of vitamin D in bone health. Future studies are needed to clarify the role of vitamin D in IBD development and disease activity and to determine its therapeutic potential for IBD disease activity.

Perspective on skeletal health in inflammatory bowel disease

Osteopenia and osteoporosis are common features in inflammatory bowel disease (IBD), comprising both Crohn's disease and ulcerative colitis. Moreover, Crohn's disease is associated with increased fracture risk. The etiology of bone loss in IBD is multifactorial. It includes insufficient intake or absorption of calcium, vitamin D, and potassium; smoking; a low peak bone mass; a low body mass index; and decreased physical activity. In several studies, it has been shown that elevated concentrations of systemic and local pro-inflammatory cytokines, including tumor necrosis factor alpha (TNF-α), interferon-γ (IFNγ), interleukin (IL)-1β, IL-4, IL-5, IL-6, IL-13, and IL-17, present in IBD patients are potentially detrimental for bone metabolism and may be responsible for bone loss and increased fracture risk. This perspective aims to review the current literature on the role of inflammatory factors in the pathophysiology of skeletal problems in IBD and to suggest potential treatment to improve bone health, based on a combination of evidence and clinical and pathophysiological reasoning.

Micronutrient Absorption and Related Outcomes in People with Inflammatory Bowel Disease: A Review

Inflammatory Bowel Disease (IBD) is a chronic disorder associated with immune dysregulation and chronic inflammation of the digestive tract. While it is poorly understood, the role of nutrition and nutrient status in the etiology of IBD and its associated outcomes has led to increased research relating to micronutrient deficiency. This review offers an overview of recent literature related to micronutrient absorption and outcomes in adults with IBD. Although the absorption and IBD-related outcomes of some micronutrients (e.g., vitamin D and iron) are well understood, other micronutrients (e.g., vitamin A) require further research. Increased research and clinician knowledge of the relationship between micronutrients and IBD may manifest in improved nutrient screening, monitoring, treatment, and outcomes for people living with IBD.

Vitamin D therapy in children with inflammatory bowel disease: A systematic review

BACKGROUND

Vitamin D deficiency is highly prevalent in children with inflammatory bowel disease (IBD). This may contribute to an increased risk of poor bone health and may also influence the course of disease. An optimal treatment strategy of vitamin D therapy in children with IBD has not yet been established.

AIM

To analyse the published intervention studies of vitamin D therapy in children with IBD.

METHODS

A systematic review was conducted of clinical studies involving children with IBD (including Crohn disease or ulcerative colitis) who had received vitamin D therapy. Studies up to March 31^st 2018 were identified through MEDLINE, PubMed, EMBASE and the Cochrane Library. Search terms included synonyms of the following terms: vitamin D, paediatric, supplementation, IBD. References of included articles based on abstract were searched for other relevant articles. All relevant articles were accessed and reviewed in full text. Studies fitting the set criteria were included and the remainder were excluded.

RESULTS

Two hundred and seventy-seven discrete articles were identified. Following assessment of these articles included in the initial search and application of inclusion and exclusion criteria, ten published studies were included in this review. The included studies showed a heterogeneity in study design, inclusion and exclusion criteria, baseline demographics and treatment strategies. Treatment regimens differed in length, supplemented form of vitamin D and factors based upon which dosage was adjusted. Each of the reports included in this review concluded their vitamin D regimens to be safe and well-tolerated. Few of the included studies reported secondary outcomes on the efficacy of vitamin D treatment upon the clinical course of disease or markers of inflammation. The majority of included trials were not sufficient in raising serum vitamin D levels to an adequate level (30 ng/mL) in children with IBD with vitamin D deficiency.

CONCLUSION

The included trials featured diverse treatment regimens that were predominantly insufficient in correcting vitamin D deficiency or maintaining adequate levels in children with IBD. Better treatment regimens are required for the management of vitamin D deficiency in children with IBD.

Nutrition in Pediatric Inflammatory Bowel Disease: A Position Paper on Behalf of the Porto Inflammatory Bowel Disease Group of the European Society of Pediatric Gastroenterology, Hepatology and Nutrition

BACKGROUND AND AIMS

A growing body of evidence supports the need for detailed attention to nutrition and diet in children with inflammatory bowel disease (IBD). We aimed to define the steps in instituting dietary or nutritional management in light of the current evidence and to offer a useful and practical guide to physicians and dieticians involved in the care of pediatric IBD patients.

METHODS

A group of 20 experts in pediatric IBD participated in an iterative consensus process including 2 face-to-face meetings, following an open call to Nutrition Committee of the European Society of Pediatric Gastroenterology, Hepatology and Nutrition Porto, IBD Interest, and Nutrition Committee. A list of 41 predefined questions was addressed by working subgroups based on a systematic review of the literature.

RESULTS

A total of 53 formal recommendations and 47 practice points were endorsed with a consensus rate of at least 80% on the following topics: nutritional assessment; macronutrients needs; trace elements, minerals, and vitamins; nutrition as a primary therapy of pediatric IBD; probiotics and prebiotics; specific dietary restrictions; and dietary compounds and the risk of IBD.

CONCLUSIONS

This position paper represents a useful guide to help the clinicians in the management of nutrition issues in children with IBD.

Treatment of vitamin D deficiency in Chinese inflammatory bowel disease patients: A prospective, randomized, open-label, pilot study

OBJECTIVE

To assess the necessity and efficacy of vitamin D (VitD) supplementation in Chinese ulcerative colitis (UC) and Crohn's disease (CD) patients with vitamin D insufficiency/deficiency.

METHODS

UC and CD patients were randomly assigned into one of the three arms for 12 months: arm A (VitD₃ 150 000 IU once per 3 months plus elemental calcium 200 mg thrice daily), arm B (elemental calcium 200 mg thrice daily) and arm C (vehicle control group), in addition to conventional treatment. Improvement in 25-hydroxyvitamin D [25(OH)D] level was the primary outcome of the study. Secondary outcomes were changes in bone mineral density (BMD) and disease activity.

RESULTS

Sixty-five UC and 59 CD patients completed the study. The difference in the pre-and post-treatment 25(OH)D [Δ25(OH)D] of arm A was significantly higher than in arm B or C (UC: 17.47 ± 13.01 ng/mL vs 5.30 ± 6.28 ng/mL or 2.02 ± 6.19 ng/mL, P < 0.001; CD: 12.47 ± 9.15 ng/mL vs 4.73 ± 6.97 ng/mL or 1.36 ± 4.75 ng/mL, P < 0.01). There was no significant difference between pre- and post-treatment BMD and disease activity in arm A compared to those in arms B and C (P > 0.05). Although the Mayo score and Crohn's disease activity index decreased by conventional treatment, serum 25(OH)D did not improve in arm C without vitamin D supplementation (P > 0.05).

CONCLUSION

VitD supplementation is necessary to treat hypovitaminosis D in UC and CD patients, even with background amelioration of disease activity.

Increased bone matrix mineralization in treatment-naïve children with inflammatory bowel disease

Inflammatory bowel disease (IBD) affects many organ systems including the skeleton. In children with IBD, bone mineral density (BMD) and bone turnover are frequently low. Disturbances in bone mineralization density distribution (BMDD) are linked to alterations in bone material strength; however, BMDD has not previously been reported in children with chronic inflammatory disorders. The aim of this study was to characterize BMDD based on quantitative backscatter electron imaging in cancellous (Cn.) and cortical (Ct.) compartments from trans-iliac biopsy samples from a cohort of 20 treatment-naïve children at the time of their IBD diagnosis (12 males, mean age 14.5±2.3years). The outcomes were compared to pediatric reference BMDD data and correlation with revisited biochemical and histomorphometric outcomes was analyzed. BMDD in treatment-naïve children with IBD was shifted toward higher calcium concentrations compared to reference: (i) In cancellous bone, the most frequent calcium concentration (Cn.CaPeak+2.8%, p=0.004) and the portion of highly mineralized bone (Cn.CaHigh+52%, p=0.009) were increased. (ii) In cortical bone, the mineralization heterogeneity (Ct.CaWidth+17.0%, p=0.001) and Ct.CaHigh (+30.4%, p=0.006) were increased. (iii) Furthermore, significant correlations with serum alkaline phosphatase (ALP), bone-specific alkaline phosphatase (bsALP), and urinary crosslinked N-telopeptide of type I collagen (uNTX) were observed: the higher CaMean (the average calcium concentration), CaPeak and CaHigh, the lower were ALP, bsALP, and uNTX (p-value from <0.001 to 0.05). Children with treatment-naïve IBD have decreased bone turnover leading to a higher bone matrix mineralization density, findings which may contribute to compromised bone strength.

Vitamins and Minerals in Inflammatory Bowel Disease

Indiscriminate use of multivitamin/mineral supplements in the general population may be misguided, but patients with chronic Inflammatory Bowel Diseases (IBD) should be monitored and compensated for nutritional deficiencies. Mechanistic links between vitamin/mineral deficiencies and IBD pathology has been found for some micronutrients and normalizing their levels is clinically beneficial. Others, like vitamin A, although instinctively desirable, produced disappointing results. Restoring normal levels of the selected micronutrients requires elevated doses to compensate for defects in absorptive or signaling mechanisms. This article describes some aspects of vitamin and mineral deficiencies in IBD, and summarizes pros and cons of supplementation.

Supplementation with 2000 IU of Cholecalciferol Is Associated with Improvement of Trabecular Bone Mineral Density and Muscle Power in Pediatric Patients with IBD

BACKGROUND

Inflammatory bowel diseases (IBD) are associated with altered bone health and increased risk for fractures. Vitamin D deficiency is frequently found in IBD; however, the effect of vitamin D supplementation on bone health of children with IBD is poorly understood. We aimed to observe the changes in volumetric bone density and dynamic muscle functions after vitamin D substitution in a cohort of pediatric patients with IBD.

METHODS

This was a prospective observational study of 55 patients (aged 5-19 years) with IBD. Bone quality was assessed using peripheral quantitative computed tomography and muscle functions by jumping mechanography at baseline and after a median of 13.8 (interquartile range, 12.0-16.0) months of daily substitution of 2000 IU of cholecalciferol.

RESULTS

Median serum levels of 25-hydroxyvitamin D increased from 58 nmol/L at the baseline visit to 85 nmol/L at the last follow-up visit (P < 0.001); no signs of overdose were reported. The Z-scores of trabecular bone mineral density, cortical bone cross-sectional area, and maximal muscle power improved significantly during the follow-up period (+0.5, P = 0.001, +0.3, P = 0.002 and +0.5, P = 0.002, respectively). Cholecalciferol substitution was positively associated with trabecular bone mineral density and maximal muscle power (estimates 0.26, 95% confidence interval 0.14-0.37, P < 0.0001 and 0.60, 95% confidence interval 0.32-0.85, P < 0.0001, respectively) but not with the Strength-Strain Index or maximal muscle force (Fmax).

CONCLUSIONS

We observed an improvement in bone and muscle parameters after cholecalciferol substitution in pediatric patients with IBD. Therefore, vitamin D substitution can be considered in such patients.

Expression of Cav1.3 calcium channel in the human and mouse colon: posttranscriptional inhibition by IFNγ

It has been hypothesized that apically expressed L-type Ca²⁺ channel Ca_v1.3 (encoded by CACNA1D gene) contributes toward an alternative TRPV6-independent route of intestinal epithelial Ca²⁺ absorption, especially during digestion when high luminal concentration of Ca²⁺ and other nutrients limit TRPV6 contribution. We and others have implicated altered expression and activity of key mediators of intestinal and renal Ca²⁺ (re)absorption as contributors to negative systemic Ca²⁺ balance and bone loss in intestinal inflammation. Here, we investigated the effects of experimental colitis and related inflammatory mediators on colonic Ca_v1.3 expression. We confirmed Ca_v1.3 expression within the segments of the mouse and human gastrointestinal tract. Consistent with available microarray data (GEO database) from inflammatory bowel disease (IBD) patients, mouse colonic expression of Ca_v1.3 was significantly reduced in trinitrobenzene sulfonic acid (TNBS) colitis. In vitro, IFNγ most potently reduced Ca_v1.3 expression. We reproduced these findings in vivo with wild-type and Stat1^-/- mice injected with IFNγ. The observed effect in Stat1^-/- suggested a noncanonical transcriptional repression or a posttranscriptional mechanism. In support of the latter, we observed no effect on the cloned Ca_v1.3 gene promoter activity and accelerated Ca_v1.3 mRNA decay rate in IFNγ-treated HCT116 cells. While the relative contribution of Ca_v1.3 to intestinal Ca²⁺ absorption and its value as a therapeutic target remain to be established, we postulate that Ca_v1.3 downregulation in IBD may contribute to the negative systemic Ca²⁺ balance, to increased bone resorption, and to reduced bone mineral density in IBD patients.

Role of Vitamin D in Inflammatory Bowel Disease

Vitamin D is a secosteroid hormone that possesses immunomodulatory properties and has been demonstrated to potentially influence inflammatory bowel disease (IBD) pathogenesis and activity. Epidemiologic data have associated vitamin D deficiency with an increased risk of IBD, hospitalizations, surgery, and loss of response to biologic therapy. Conversely, IBD itself can lead to vitamin D deficiency. This bidirectional relationship between vitamin D and IBD suggests the need for monitoring and repletion of vitamin D, as needed, in the IBD patient. This review discusses the role of vitamin D in IBD and provides practical guidance on vitamin D repletion.

Preventive health measures in inflammatory bowel disease

We aim to review the literature and provide guidance on preventive health measures in inflammatory bowel disease (IBD). Structured searches were performed in PubMed, MEDLINE, EMBASE, Web of Science and Cochrane Library from January 1976 to June 2016 using the following keywords: (inflammatory bowel disease OR Crohn’s disease OR ulcerative colitis) AND (health maintenance OR preventive health OR health promotion). Abstracts of the articles selected from each of these multiple searches were reviewed, and those meeting the inclusion criteria (that is, providing data regarding preventive health or health maintenance in IBD patients) were recorded. Reference lists from the selected articles were manually reviewed to identify further relevant studies. Patients with IBD are at increased risk of developing adverse events related to the disease course, therapeutic interventions, or non-adherence to medication. Recent studies have suggested that IBD patients do not receive preventive services with the same thoroughness as patients with other chronic diseases. Preventive health measures can avert morbidity and improve the quality of life of patients with IBD. Gastroenterologists and primary care physicians (PCPs) should have an up to date working knowledge of preventive health measures for IBD patients. A holistic approach and better communication between gastroenterologists and PCPs with explicit clarification of roles will prevent duplication of services and streamline care.

Clinical Course of Bone Metabolism Disorders in Patients with Inflammatory Bowel Disease: A 5-Year Prospective Study

BACKGROUND

The clinical course of bone mineral density (BMD) disorders and the efficacy of treatment of osteopenia and osteoporosis have been poorly studied in patients with inflammatory bowel disease (IBD). The objective was to study the course of BMD disorders in patients with IBD, analyze the factors influencing their development, and assess the effect of treatment with calcium, vitamin D, and bisphosphonates.

METHODS

Consecutive patients with IBD were included and followed up for 5 years. After a baseline densitometry, calcium (1000 mg/d) and vitamin D (800 IU/d) were administered to patients with osteopenia; bisphosphonates to patients with osteoporosis; and patients with normal BMD were only followed-up. After completing the follow-up period, a second densitometry was performed.

RESULTS

One hundred patients were initially included, 60% having a low BMD (44% osteopenia and 16% osteoporosis). Fifty-eight patients completed the follow-up period. At baseline, osteopenia was more frequently found in Crohn's disease than in ulcerative colitis (63% versus 21%, P < 0.05). In patients with normal BMD at baseline, age, smoking habit, and the presence of flares during follow-up were associated with the development of osteopenia. Treatment with calcium and vitamin D improved the hip T-score in patients with osteopenia (-1.03 versus -0.58, P < 0.001) and bisphosphonates provided the same improvement (-1.482 versus -1.072, P < 0.05) in patients with osteoporosis.

CONCLUSIONS

Age, smoking habit, and IBD activity negatively influence the clinical course of BMD. Treatment with calcium and vitamin D improves hip T-score in patients with osteopenia whereas bisphosphonates improve hip T-score in patients with osteoporosis.

The management of osteoporosis in children

This article reviews the manifestations and risk factors associated with osteoporosis in childhood, the definition of osteoporosis and recommendations for monitoring and prevention. As well, this article discusses when a child should be considered a candidate for osteoporosis therapy, which agents should be prescribed, duration of therapy and side effects. There has been significant progress in our understanding of risk factors and the natural history of osteoporosis in children over the past number of years. This knowledge has fostered the development of logical approaches to the diagnosis, monitoring, and optimal timing of osteoporosis intervention in this setting. Current management strategies are predicated upon monitoring at-risk children to identify and then treat earlier rather than later signs of osteoporosis in those with limited potential for spontaneous recovery. On the other hand, trials addressing the prevention of the first-ever fracture are still needed for children who have both a high likelihood of developing fractures and less potential for recovery. This review focuses on the evidence that shapes the current approach to diagnosis, monitoring, and treatment of osteoporosis in childhood, with emphasis on the key pediatric-specific biological principles that are pivotal to the overall approach and on the main questions with which clinicians struggle on a daily basis. The scope of this article is to review the manifestations of and risk factors for primary and secondary osteoporosis in children, to discuss the definition of pediatric osteoporosis, and to summarize recommendations for monitoring and prevention of bone fragility. As well, this article reviews when a child is a candidate for osteoporosis therapy, which agents and doses should be prescribed, the duration of therapy, how the response to therapy is adjudicated, and the short- and long-term side effects. With this information, the bone health clinician will be poised to diagnose osteoporosis in children and to identify when children need osteoporosis therapy and the clinical outcomes that gauge efficacy and safety of treatment.

1,25-Dihydroxyvitamin D Protects Intestinal Epithelial Barrier by Regulating the Myosin Light Chain Kinase Signaling Pathway

BACKGROUND

The myosin light chain kinase (MLCK) pathway controls intestinal epithelial barrier permeability by regulating the tight junction. 1,25-dihydroxyvitamin D (1,25(OH)2D3)-vitamin D receptor (VDR) signaling protects the epithelial barrier, but the molecular mechanism is incompletely understood.

METHODS

MLCK activation and barrier permeability were studied using monolayers of HCT116, Caco-2, and SW480 cells treated with tissue necrosis factor α with or without 1,25(OH)2D3. The MLCK pathway was analyzed in normal and inflamed colonic biopsies from patients with ulcerative colitis. Colonic mucosal barrier permeability and MLCK activation were also investigated using trinitrobenzene sulfonic acid-induced colitis models in vitamin D analog paricalcitol-treated wild-type mice and mice carrying VDR deletion in colonic epithelial cells.

RESULTS

Tissue necrosis factor α increased cell monolayer permeability and induced long isoform of MLCK expression and myosin II regulatory light chain (MLC) phosphorylation, and 1,25(OH)2D3 blocked tissue necrosis factor α-induced increases in monolayer permeability and MLCK-MLC pathway activation by a VDR-dependent fashion. 1,25(OH)2D3 directly suppressed long MLCK expression by attenuating NF-κB activation, and chromatin immunoprecipitation assays confirmed that 1,25(OH)2D3 disrupted p65 binding to 3 κB sites in long MLCK gene promoter. In human ulcerative colitis biopsies, VDR reduction was associated with increases in long MLCK expression and MLC phosphorylation. In trinitrobenzene sulfonic acid colitis models, paricalcitol ameliorated colitis, attenuated the increase in mucosal barrier permeability, and inhibited long MLCK induction and MLC phosphorylation. In contrast, mice with colonic epithelial VDR deletion exhibited more robust increases in mucosal barrier permeability and MLCK activation compared with wild-type mice.

CONCLUSIONS

These data demonstrate that 1,25(OH)2D3-VDR signaling preserves the mucosal barrier integrity by abrogating MLCK-dependent tight junction dysregulation during colonic inflammation.

[Vitamin D deficiency in childhood: an opportunity for prevention]

The prevalence of vitamin D deficiency in the pediatric population has increased in recent years and continues to be underdiagnosed and undertreated. According to data from the "ENSANUT 2006" (National Health and Nutrition Survey), the prevalence of vitamin D deficiency in Mexico was 16% in children aged 2-12 years. Vitamin D plays a critical role in the formation and bone homeostasis and consequently on growth. Its deficiency is clearly associated with diseases such as rickets and osteomalacia, and it has been linked to other diseases such as obesity, metabolic syndrome, diabetes, cancer, respiratory infections and immune system disease. Specific risk groups have been described in the medical literature for vitamin D deficiency in which supplementation may offer a benefit. Currently, there is still controversy in defining the serum levels of proficiency and dose supplementation. In Mexico, the daily suggested intake of vitamin D is 5.6μg (224 IU), which is significantly lower than the recommendations in the U.S. and Europe (i.e., between 400 and 1000 IU/day). An increase in vitamin D deficiency has been reported in recent years. There is no consensus regarding the sufficiency levels of vitamin D. Cut-off values vary from 20 to 30ng/ml. Therefore, the objective of this review was to provide an overview of the problem in the pediatric population and to describe the groups at risk, as well as to analyze the current recommendations for vitamin D supplementation. Vitamin D deficiency was considered rare in Mexico according to the National Institute of Medical Science and Nutrition Salvador Zubirán. Lack of evidence did not help to establish the international recommended daily intake. Currently, vitamin D deficiency must be recognized as a health problem, worthy of attention and action. We suggest that prospective studies are carried out in our country where the relationship between serum vitamin D deficiency and poor bone mineralization will be established.

Vitamin D supplementation and risk of toxicity in pediatrics: a review of current literature

CONTEXT

Although vitamin D toxicity is rare in children, increased use of vitamin D formulations, re-examination of optimal vitamin D levels, and use of higher doses lend potential for an increased incidence of vitamin D toxicity.

EVIDENCE ACQUISITION

A PubMed search was conducted through May 2013 for cases of vitamin D intoxication and vitamin D trials in pediatrics. Safety data were collected and reviewed.

EVIDENCE SYNTHESIS

A small number of pediatric studies tested vitamin D doses at or above the currently recommended upper tolerable intake. In children and adolescents, vitamin D excess was rare and usually asymptomatic. Recent cases of intoxication relate to errors in manufacturing, formulation, or prescription; involve high total intake in the range of 240,000 to 4,500,000 IU; and present with severe hypercalcemia, hypercalciuria, or nephrocalcinosis. However, mild hypercalcemia and hypervitaminosis using currently recommended doses have been reported in infants with rickets.

CONCLUSIONS

Although rare, cases of vitamin D intoxication that present with dramatic life-threatening symptoms still occur in children. Moreover, recent studies in infants raise a potential need for monitoring vitamin D levels when doses at or above the currently recommended upper range are used. Further studies are needed to clarify these findings. The Drugs and Therapeutics Committee of the Pediatric Endocrine Society suggests obtaining serum 25-hydroxyvitamin D levels in infants and children who receive long-term vitamin D supplementation at or above the upper level intake that is currently recommended.

Pathological fractures in paediatric patients with inflammatory bowel disease

Paediatric inflammatory bowel disease (IBD), especially Crohn's disease (CD), is commonly associated with poor skeletal health, related to the direct effects of chronic inflammation, prolonged use of glucocorticoid (GC), poor nutrition, delayed puberty and low muscle mass. Low bone mineral density is commonly reported, although the prevalence of long bone fractures may not be increased in these patients. Emerging evidence however suggests that there may be an increased risk of vertebral fractures (VFs) in this group. VFs presenting at diagnosis of paediatric CD, prior to any GC exposure, have been reported, highlighting the deleterious effect of inflammation on skeletal health. This paper reviews the published literature on pathophysiology of skeletal morbidity and fractures in paediatric IBD, illustrated with a new case report of multiple VFs in a prepubertal girl with CD, soon after diagnosis, who received minimal amounts of oral GC. Optimising control of disease, addressing vitamin D deficiency, encouraging physical activity and ensuring normal growth and pubertal progression are paramount to management of bone health in these patients. Despite the lack of evidence, there may be a place for bisphosphonate treatment, especially in the presence of symptomatic pathological fractures, but this requires close monitoring by clinicians with expertise in paediatric bone health.

CONCLUSION

Chronic inflammation mediated by pro-inflammatory cytokines may have adverse effects on skeletal health in paediatric patients with IBD. The risk of vertebral fractures may be increased, even without exposure to glucocorticoid. Clinical monitoring of these patients requires careful attention to the various factors that impact on bone health.

Efficacy and safety of medical therapy for low bone mineral density in patients with inflammatory bowel disease: a meta-analysis and systematic review

BACKGROUND & AIMS

Patients with inflammatory bowel disease (IBD) are at risk for osteoporosis and fracture. However, the efficacy of medical treatments for osteoporosis in increasing bone mineral density (BMD) in patients with IBD has not been well characterized.

METHODS

We conducted a meta-analysis and systematic review of controlled trials to evaluate the efficacy and safety of medical therapies used for low BMD in patients with IBD (Crohn's disease, ulcerative colitis, or indeterminate colitis). We searched MEDLINE, EMBASE, Google scholar, the University Hospital Medical Information Network (UMIN) Clinical Trials Registry, and Cochrane Central Register of Controlled Trials for studies that assessed the efficacy of medical treatment for low BMD in patients with IBD. We also manually searched abstracts from scientific meetings and bibliographies of identified articles for additional references. The primary outcome assessed was changes in BMD at the lumbar spine. We also collected data on hip BMD, numbers of new fractures, and adverse effects. Data were pooled by using random-effects models and by mixed-effects analysis for primary aims, when subgroup analysis by individual drug was possible.

RESULTS

We analyzed data from 19 randomized controlled studies; 2 used calcium and vitamin D as therapies, 13 used bisphosphonates, 4 used fluoride, 1 used calcitonin, and 1 used low-impact exercise. The pooled effect of bisphosphonates was greater than that of controls in increasing BMD at the lumbar spine (standard difference in means, 0.51; 95% confidence interval, 0.29-0.72) and hip (standard difference in means, 0.26; 95% confidence interval, 0.04-0.49) with comparable tolerability, and the risk of vertebral fractures was reduced. Fluoride increased lumbar spine BMD, but its ability to reduce risk of fracture was unclear. There was no evidence that the other interventions increased BMD.

CONCLUSIONS

On the basis of a meta-analysis, bisphosphonate is effective and well tolerated for the treatment of low BMD in patients with IBD and reduces the risk of vertebral fractures. There are insufficient data to support the efficacy of calcium and vitamin D, fluoride, calcitonin, or low-impact exercise. However, the small number of randomized controlled trials limited our meta-analysis.

Vitamin D status and bone mineral density in African American children with Crohn disease

BACKGROUND

Vitamin D deficiency and low bone mineral density (BMD) are complications of inflammatory bowel disease. Vitamin D deficiency is more prevalent among African Americans compared with whites. There are little data comparing differences in serum 25-hydroxyvitamin D (25OHD) concentrations and BMD between African American and white children with Crohn disease (CD).

METHODS

We compared serum 25OHD concentrations of African American children with CD (n = 52) to white children with CD (n = 64) and healthy African American controls (n = 40). We also analyzed BMD using dual-energy x-ray absorptiometry results from our pediatric CD population.

RESULTS

African American children with CD had lower serum 25OHD concentrations (16.1 [95% confidence interval, CI 14.5-17.9] ng/mL) than whites with CD (22.3 [95% CI 20.2-24.6] ng/mL; P < 0.001). African Americans with CD and controls exhibited similar serum 25OHD concentration (16.1 [95% CI 14.5-17.9] vs 16.3 [95% CI 14.4-18.4] ng/mL; NS). African Americans with CD exhibited no difference in serum 25OHD concentration when controlling for seasonality, disease severity, and surgical history, although serum 25OHD concentration was significantly decreased in overweight children (body mass index ≥85%, P = 0.003). Multiple regression analysis demonstrated that obese African American girls with CD had the lowest serum 25OHD concentrations (9.6 [95% CI 6.8-13.5] ng/mL). BMD was comparable between African American and white children with CD (z score -0.4 ± 0.9 vs -0.7 ± 1.2; NS).

CONCLUSIONS

African American children with CD are more likely to have vitamin D deficiency compared with white children with CD, but have similar BMD. CD disease severity and history of surgery do not affect serum 25OHD concentrations among African American children with CD. African American children have low serum 25OHD concentrations, independent of CD, compared with white children. Future research should focus on how race affects vitamin D status and BMD in children with CD.

Post-translational loss of renal TRPV5 calcium channel expression, Ca(2+) wasting, and bone loss in experimental colitis

BACKGROUND & AIMS

Dysregulated Ca(2+) homeostasis likely contributes to the etiology of inflammatory bowel disease-associated loss of bone mineral density. Experimental colitis leads to decreased expression of Klotho, a protein that supports renal Ca(2+) reabsorption by stabilizing the transient receptor potential vanilloid 5 (TRPV5) channel on the apical membrane of distal tubule epithelial cells.

METHODS

Colitis was induced in mice via administration of 2,4,6-trinitrobenzenesulfonic acid (TNBS) or transfer of CD4(+)interleukin-10(-/-) and CD4(+), CD45RB(hi) T cells. We investigated changes in bone metabolism, renal processing of Ca(2+), and expression of TRPV5.

RESULTS

Mice with colitis had normal serum levels of Ca(2+) and parathormone. Computed tomography analysis showed a decreased density of cortical and trabecular bone, and there was biochemical evidence for reduced bone formation and increased bone resorption. Increased fractional urinary excretion of Ca(2+) was accompanied by reduced levels of TRPV5 protein in distal convoluted tubules, with a concomitant increase in TRPV5 sialylation. In mouse renal intermedullary collecting duct epithelial (mIMCD3) cells transduced with TRPV5 adenovirus, the inflammatory cytokines tumor necrosis factor, interferon-γ, and interleukin-1β reduced levels of TRPV5 on the cell surface, leading to its degradation. Cytomix induced interaction between TRPV5 and UBR4 (Ubiquitin recoginition 4), an E3 ubiquitin ligase; knockdown of UBR4 with small interfering RNAs prevented cytomix-induced degradation of TRPV5. The effects of cytokines on TRPV5 were not observed in cells stably transfected with membrane-bound Klotho; TRPV5 expression was preserved when colitis was induced with TNBS in transgenic mice that overexpressed Klotho or in mice with T-cell transfer colitis injected with soluble recombinant Klotho.

CONCLUSIONS

After induction of colitis in mice via TNBS administration or T-cell transfer, tumor necrosis factor and interferon-γ reduced the expression and activity of Klotho, which otherwise would protect TRPV5 from hypersialylation and cytokine-induced TRPV5 endocytosis, UBR4-dependent ubiquitination, degradation, and urinary wasting of Ca(2+).

High vitamin D3 diet administered during active colitis negatively affects bone metabolism in an adoptive T cell transfer model

Decreased bone mineral density (BMD) represents an extraintestinal complication of inflammatory bowel disease (IBD). Vitamin D₃ has been considered a viable adjunctive therapy in IBD. However, vitamin D₃ plays a pleiotropic role in bone modeling and regulates the bone formation-resorption balance, depending on the physiological environment, and supplementation during active IBD may have unintended consequences. We evaluated the effects of vitamin D₃ supplementation during the active phase of disease on colonic inflammation, BMD, and bone metabolism in an adoptive IL-10-/- CD4⁺ T cell transfer model of chronic colitis. High-dose vitamin D₃ supplementation for 12 days during established disease had negligible effects on mucosal inflammation. Plasma vitamin D₃ metabolites correlated with diet, but not disease, status. Colitis significantly reduced BMD. High-dose vitamin D₃ supplementation did not affect cortical bone but led to a further deterioration of trabecular bone morphology. In mice fed a high vitamin D₃ diet, colitis more severely impacted bone formation markers (osteocalcin and bone alkaline phosphatase) and increased bone resorption markers, ratio of receptor activator of NF-κB ligand to osteoprotegrin transcript, plasma osteoprotegrin level, and the osteoclast activation marker tartrate-resistant acid phosphatase (ACp5). Bone vitamin D receptor expression was increased in mice with chronic colitis, especially in the high vitamin D₃ group. Our data suggest that vitamin D₃, at a dose that does not improve inflammation, has no beneficial effects on bone metabolism and density during active colitis or may adversely affect BMD and bone turnover. These observations should be taken into consideration in the planning of further clinical studies with high-dose vitamin D₃ supplementation in patients with active IBD.

The efficacy and safety of bisphosphonates for osteoporosis or osteopenia in Crohn's disease: a meta-analysis

BACKGROUND

Crohn's disease impacts the bone health of patients and results in a high prevalence of low bone mineral density (BMD) disease such as osteoporosis and osteopenia. Bisphosphonates can reduce bone loss by inhibiting bone resorption.

AIM

To assess the effectiveness and safety of bisphosphonates for osteoporosis or osteopenia in Crohn's disease.

METHODS

A literature search included PubMed, EMBASE, the Science Citation Index, and the Cochrane Library was conducted to identify studies up to March, 2012. Randomized controlled trials (RCTs) comparing bisphosphonates with placebo or no intervention for osteoporosis or osteopenia in adult patients with Crohn's disease were analyzed.

RESULTS

Five RCTs involving 423 participants were included. All patients received daily calcium and vitamin D supplementation. Overall, bisphosphonates improved hip BMD at 12 months (n = 193, MD = 0.99, 95 % CI: 0.14-1.84) compared with placebos or no intervention. No significant differences of spine BMD at both 12 months (n = 193, MD = 1.78, 95 % CI: -0.99 to 4.55) and 24 months (n = 231, MD = 0.70 %, 95 % CI: -0.48 to 1.88), hip BMD at 24 months (n = 231, MD = 0.25 %, 95 % CI: -0.65 to 1.15), new vertebral fractures (n = 117, RD = -0.01, 95 % CI: -0.08 to 0.05) or adverse events (n = 422, RR = 1.03, 95 % CI: 0.71-1.49) between bisphosphonates groups and control groups were noted. Subgroup analyses of participants treated with corticosteroid in the preceding year found no difference between two groups.

CONCLUSIONS

There was no evidence to support the use of bisphosphonates for osteoporosis or osteopenia in Crohn's disease. More randomized controlled clinical trials assessing the effects of bisphosphonates are needed.

Vitamin D: effects on childhood health and disease

Vitamin D is a key nutrient for both healthy children and those with chronic illnesses. Understanding its roles in health and disease has become one of the most important issues in the nutritional management of children. Formal guidelines related to nutrient requirements for vitamin D in healthy children, recommending dietary intakes of 400 IU per day for infants and 600 IU per day for children over 1 year of age, were released by the Institute of Medicine in November 2010. However, application of these guidelines to children with acute and chronic illnesses is less clear. In this Review, we consider major illness categories and specific examples of conditions in children that might be affected by vitamin D. This information can be used in developing both model systems of investigation and clinical trials of vitamin D in children with acute and chronic illnesses.

Longitudinal assessment of bone mineral density in children and adolescents with inflammatory bowel disease

OBJECTIVES

Low bone mineral density (BMD) is recognized as a potential problem in children with inflammatory bowel disease (IBD). We aimed to describe the longitudinal development of BMD in a population of Swedish pediatric patients with IBD.

METHODS

A total of 144 patients with IBD (93 males; 83 with ulcerative colitis [UC], 45 with Crohn disease [CD]) were examined with dual-energy x-ray absorptiometry at baseline. At follow-up 2 years later, 126 of the initial 144 patients were reexamined. BMD values are expressed as z scores.

RESULTS

Children with UC and CD had significantly lower mean BMD z scores for the lumbar spine (LS) at baseline and after 2 years. The reduction in BMD was equally pronounced in patients with UC and CD, and neither group improved their z score during the follow-up period. Furthermore, significantly lower mean BMD z scores for the LS were found at baseline in boys (-1.1 SD, ±2.7 SD, P < 0.001), but not in girls (-0.0 SD, ±3.0 SD). This finding remained unchanged at follow-up. Subanalyses of the different age groups at baseline showed the lowest BMD values in the group of patients ages 17 to 19 years in boys (mean z score for the LS 1.59 SD, ±3.1 SD) and in girls (mean z score for the LS -3.40 SD, ±3.1 SD); however, at follow-up, these patients had improved their BMD significantly (mean change z score for the LS 1.00 SD, 95% CI 0.40-1.60; 1.90 SD, 95% CI 0.60-3.20).

CONCLUSIONS

In this longitudinal study, the entire group of pediatric patients with IBD showed permanent decreases in their BMD z scores for the LS; however, our data indicate that afflicted children have the potential to improve their BMD by the time they reach early adulthood.

The importance of vitamins D and K for the bone health and immune function in inflammatory bowel disease

PURPOSE OF REVIEW

This review summarizes the recent literature about the roles of vitamins D and K in bone metabolism and immunity-mediated inflammatory processes in inflammatory bowel diseases (IBDs).

RECENT FINDINGS

The levels of vitamins D and K are lower than normal in patients with IBD, especially in Crohn's disease. Although vitamins D and K are important for the maintenance of bone mineral density in non-IBD patients, an association between vitamins D or K and bone metabolism is not apparent in IBD patients. Recent studies showed that vitamins D and K are suggested to have immune-suppressive effects, both in animal models of colitis and human trials. In particular, vitamin D suppresses dendritic and T-cell functions by inhibiting the production of proinflammatory cytokines. Insufficiency of vitamin D is associated with the activated phenotype of IBD.

SUMMARY

Vitamins D and K potentially contribute to the maintenance of bone health in IBD, but this effect may be diminished by other factors such as steroid use, reduced exposure to sunlight, and inflammatory cytokines. Vitamin D and possibly vitamin K are suggested to be involved in the suppression of immune-mediated inflammation and modulation of disease activity.

Nutritional and probiotic supplementation in colitis models

In vitro and animals models have long been used to study human diseases and identify novel therapeutic approaches that can be applied to combat these conditions. Ulcerative colitis and Crohn's disease are the two main entities of inflammatory bowel disease (IBD). There is an intricate relationship between IBD features in human patients, in vitro and animal colitis models, mechanisms and possible therapeutic approaches in these models, and strategies that can be extrapolated and applied in humans. Malnutrition, particularly protein-energy malnutrition and vitamin and micronutrient deficiencies, as well as dysregulation of the intestinal microbiota, are common features of IBD. Based on these observations, dietary supplementation with essential nutrients known to be in short supply in the diet in IBD patients and with other molecules believed to provide beneficial anti-inflammatory effects, as well as with probiotic organisms that stimulate immune functions and resistance to infection has been tested in colitis models. Here we review current knowledge on nutritional and probiotic supplementation in in vitro and animal colitis models. While some of these strategies require further fine-tuning before they can be applied in human IBD patients, their intended purpose is to prevent, delay or treat disease symptoms in a non-pharmaceutical manner.

Nutritional management of adults with inflammatory bowel disease: practical lessons from the available evidence

Inflammatory bowel disease (IBD) is associated with impairment of nutritional status both anthropometrically and biochemically, which results from both qualitative and quantitative changes in dietary intake alongside disease activity. Dietary intervention to replace deficiency is essential and may also be used to treat active disease and to reduce symptoms. The evidence for dietary interventions in this area is reviewed and the following recommendations made: ■Assessment of nutritional status is an essential part of the investigation of all patients with IBD and deficiency should be actively sought.■Any patient with macro- or micronutrient deficiency should be referred for dietetic assessment.■Micronutrient deficiency (most frequently iron, vitamin B12, folate and magnesium) should be replaced aggressively, parenterally if necessary.■Significant improvement in gastrointestinal symptoms can be achieved by low-residue diets (for stricturing disease) and (always under dietetic supervision) management of lactose and other intolerances.■Irritable bowel syndrome symptoms in patients with IBD can respond to low fermentable oligo-, di-, monosaccharide and polyol (FODMAP) diets, again this must be done under dietetic supervision.■Active Crohn's disease can be treated by exclusive enteral nutrition (elemental/polymeric/altered fat formulations all have equivalent efficacy).■Enteral nutrition can maintain remission in Crohn's disease and in this context can be given alongside normal oral intake.■Nutritional support does not have an established role in the treatment of active ulcerative colitis, other than in the management of malnutrition.■Total parenteral nutrition should not be used unless intestinal failure occurs.■There is insufficient evidence to support the routine use of Ω3 fish oil, prebiotics and glutamine in the treatment of active IBD.

Efficacy and harms of nasal calcitonin in improving bone density in young patients with inflammatory bowel disease: a randomized, placebo-controlled, double-blind trial

OBJECTIVES

There are very few published studies of agents having the potential to improve bone health in children with inflammatory bowel disease (IBD). The objective of this study was to establish the efficacy and safety of intranasal calcitonin in improving bone mineral density (BMD) in young patients with IBD and to define additional factors that impact bone mineral accrual.

METHODS

We conducted a randomized, placebo-controlled, double-blind clinical trial in 63 participants, ages 8-21 years, with a spinal BMD Z-score ≤ -1.0 s.d. measured by dual energy X-ray absorptiometry. Subjects were randomized to 200 IU intranasal calcitonin (n=31) or placebo (n=32) daily. All received age-appropriate calcium and vitamin D supplementation. Subsequent BMD measurements were obtained at 9 and 18 months.

RESULTS

Intranasal calcitonin was well tolerated. Adverse event frequency was similar in both treatment groups, and such events were primarily minor, reversible, and limited to the upper respiratory tract. The BMD Z-score change documented at screening and 9 months and screening and 18 months did not differ between the two therapeutic arms. In participants with Crohn's disease, the spinal BMD Z-score improved between screening and 9 months (change in spine BMD Z-score (ΔZSBMD)(9-0)) in the calcitonin group (ΔZSBMD(9-0)(calcitonin)=0.21 (0.37), ΔZSBMD(9-0)(placebo)=-0.15 (0.5), P=0.02); however, this was only a secondary subgroup analysis. Bone mineral accrual rate during the trial did not lead to normalization of BMD Z-score in this cohort. Factors favoring higher bone mineral accrual rate were lower baseline BMD and higher baseline body mass index Z-score, improvement in height Z-score, higher serum albumin, hematocrit and iron concentration, and more hours of weekly weight-bearing activity. Factors associated with lower bone mineral accrual rate were more severe disease-as indicated by elevated inflammatory markers, need for surgery, hospitalization, and the use of immunomodulators-and higher daily caffeine intake.

CONCLUSIONS

Intranasal calcitonin is well tolerated but does not offer a long-term advantage in youth with IBD and decreased BMD. Bone mineral accrual rate remains compromised in youth with IBD and low BMD raising concerns for long-term bone health outcomes. Improvement in nutritional status, catch-up linear growth, control of inflammation, increase in weight-bearing activity, and lower daily caffeine intake may be helpful in restoring bone density in children with IBD and low BMD.

High-dose vitamin D supplements are not associated with linear growth in a large Finnish cohort

High vitamin D intake in childhood has been suggested to have an adverse influence on linear growth. In Finland, in the mid-1960s the official recommendation for infant vitamin D supplementation was 2000 IU/d (50 μg/d). We investigated whether high-dose vitamin D supplementation in infancy was associated with subsequent growth in height. We used data from a prospective population-based birth cohort study including all children due to be born in the 2 northernmost provinces in Finland in 1966 (12,058 live-births, coverage 96%). Information on each participant's height was collected at birth and ages 1, 14, and 31 y, as were possible confounding factors (data for analyses available from 10,060 singletons). Information on the frequency and dose of vitamin D supplementation was collected in 1967 when participants were 1 y of age. A weak association was found between frequency of vitamin D supplementation with greater height at age 1 y (P = 0.005), which was explained by birth characteristics and maternal and social factors (adjusted P = 0.34). Neither frequency nor dose of vitamin D supplementation was associated with height at 14 or 31 y (P > 0.13). To conclude, contrary to proposed evidence suggesting that vitamin D has a negative influence on growth rate at a dosage of ~2000 IU/d, supplementation at this level in the Northern Finland Birth Cohort was not associated with reduced height at any age studied.

Vitamin D status and supplementation in pediatric gastrointestinal disease

PURPOSE

To evaluate vitamin D status and supplementation in the pediatric population with common gastrointestinal diseases. The literature was searched for studies on vitamin D status in children with inflammatory bowel disease (IBD), celiac disease, and liver disease. Vitamin D supplementation in healthy children was also reviewed.

CONCLUSIONS

Those with gastrointestinal diseases are more likely to have vitamin D deficiency as a result of malabsorption. Current recommendations for supplementation may be too low to achieve optimal levels.

PRACTICE IMPLICATIONS

It is important to monitor vitamin D levels in pediatric populations with gastrointestinal diseases and appropriately treat levels that are insufficient.

Pediatric inflammatory bowel disease and bone health

Childhood and adolescence are important periods for bone development. Any disease that affects bone health has the potential to affect the bones not only in the short term but also later in life. Bone health abnormalities in patients with inflammatory bowel disease are being increasingly recognized. Screening the at-risk patient is important so that appropriate treatments can be instituted. Treatment options are limited to vitamin D and calcium supplementation, control of underlying disease activity, and appropriate physical activity. The role of bisphosphonates in these patients needs to be better studied, and treatment with bisphosphonates may be considered for some patients in consultation with a bone health expert.

Advances in the understanding of mineral and bone metabolism in inflammatory bowel diseases

Chronic inflammatory disorders such as inflammatory bowel diseases (IBDs) affect bone metabolism and are frequently associated with the presence of osteopenia, osteoporosis, and increased risk of fractures. Although several mechanisms may contribute to skeletal abnormalities in IBD patients, inflammation and inflammatory mediators such as TNF, IL-1β, and IL-6 may be the most critical. It is not clear whether the changes in bone metabolism leading to decreased mineral density are the result of decreased bone formation, increased bone resorption, or both, with varying results reported in experimental models of IBD and in pediatric and adult IBD patients. New data, including our own, challenge the conventional views, and contributes to the unraveling of an increasingly complex network of interactions leading to the inflammation-associated bone loss. Since nutritional interventions (dietary calcium and vitamin D supplementation) are of limited efficacy in IBD patients, understanding the pathophysiology of osteopenia and osteoporosis in Crohn's disease and ulcerative colitis is critical for the correct choice of available treatments or the development of new targeted therapies. In this review, we discuss current concepts explaining the effects of inflammation, inflammatory mediators and their signaling effectors on calcium and phosphate homeostasis, osteoblast and osteoclast function, and the potential limitations of vitamin D used as an immunomodulator and anabolic hormone in IBD.

Zoledronic acid for the treatment of osteopenia in pediatric Crohn's disease

BACKGROUND

Pediatric patients with Crohn's disease often have low bone mass (osteopenia) for age. No randomized, placebo-controlled trials using zoledronic acid have ever been performed in this population. The objective of this study was to assess the efficacy of zoledronic acid in children with Crohn's disease and osteopenia.

METHODS

A double-blind, randomized, placebo-controlled design was used. Thirteen adolescents received either a single intravenous dose of zoledronic acid (0.066 mg/kg, max 4 mg, n= 7) or saline placebo (n= 6). The primary outcome was change in lumbar spine bone mineral density (LSBMD) z-score at 6 months. Secondary outcomes included bone markers and adverse events.

RESULTS

At 6 months, the change in LSBMD z-score was significantly higher in the zoledronic acid group compared to placebo (0.7 vs 0.1, P < 0.001). Volumetrically adjusted LSBMD z-score also significantly increased in the treated group. This significant difference persisted until 12 months. With zoledronic acid, urinary C-telopeptide excretion decreased by 50% at 6 months and remained suppressed at 12 months (P= 0.02), but no changes were observed with placebo. Both groups had similar adverse events which included transient fever, arthralgias, and nausea (3/7 treated, 2/6 placebo, P= NS).

CONCLUSIONS

In this study, zoledronic acid demonstrated a significant increase in LSBMD at 6 and 12 months following a well-tolerated infusion.

Nutritional considerations in pediatric inflammatory bowel disease

Nutrition is a critical part of the management of inflammatory bowel disease (IBD) in children and adults. Malnutrition and micronutrient deficiencies are common at the time of diagnosis and may persist throughout the course of the disease. There are a number of similarities with regards to the nutritional complications and the approach to nutritional management in IBD in both children and adults, but there are also important differences. Growth failure, pubertal delay and the need for corticosteroid-sparing regimens are of higher importance in pediatrics. In the pediatric population, exclusive enteral nutrition may be equivalent to corticosteroids in inducing remission in acute Crohn's disease, and may have benefits over corticosteroids in children. Adherence with exclusive enteral nutrition is better in children than in adults. Iron deficiency anemia is an important problem for adults and children with IBD. Intravenous iron administration may be superior to oral iron supplementation. Ensuring adequate bone health is another critical component of nutritional management in IBD, but guidelines for screening and therapeutic interventions for low bone mineral density are lacking in children.

Chronic pediatric inflammatory diseases: effects on bone

In children, chronic inflammatory diseases present a significant challenge to long-term skeletal health. These conditions are often associated with poor appetite and suboptimal overall nutrition, altered nutrient utilization, delayed puberty, inactivity, and reduced muscle mass, all of which can alter bone metabolism. In addition, bone cell activity is susceptible to the effects of the immune response that characterizes these diseases. Moreover, drugs used to treat these maladies, notably glucocorticoids, may have negative effects on bone formation and on linear growth in developing children. As a result, predicted peak bone mass may not be achieved, and fracture risk may be increased in the short term or in the future. Studies using primarily dual energy X-ray absorptiometry have documented that deficits in bone mass are common in these diseases. However, there are wide variations in the prevalence of low bone mass, largely due to differences in the characteristics of each study population. Recent studies provide insight into the pathogenesis of decreased bone mass in these conditions. In this paper we will provide an overview of the effects of chronic inflammatory conditions on bone mass in children. We will also present relevant data from adult patients, when pediatric data are scant or not available.