Preventing vitamin D toxicity in patients with sarcoidosis

Increased brain vitamin D receptor expression and decreased expression of cathelicidin antimicrobial peptide in individuals who died by suicide

Vitamin D deficiency is associated with immune dysregulation, increased vulnerability to infections, depression, and suicidal behavior. One mediator of vitamin D-dependent immune regulation and antimicrobial defense is the cathelicidin antimicrobial peptide (LL-37), encoded by the cathelicidin-related antimicrobial peptide (CRAMP) gene. We compared the mRNA expression of the CRAMP gene, the vitamin D receptor (VDR) gene, as well as the CYP27B1 and CYP24A1 genes (involved in vitamin D metabolism) in the dorsolateral prefrontal cortex (dlPFC) and anterior cingulate cortex (ACC) between depressed individuals who died by suicide (n = 15) and matched (age, gender, and post-mortem interval) non-psychiatric controls (n = 15). Gene expression was measured through qRT-PCR with TaqMan® primers and probes, with GAPDH and β-actin genes as endogenous controls. Statistical analyses included t-tests and Pearson correlations. CRAMP mRNA expression was downregulated and VDR mRNA expression was upregulated in both dlPFC and ACC in suicides relative to controls, with no significant differences in expression of CYP24A1 and CYP27B1. To our knowledge, this is the first study on brain cathelicidin expression in the human brain in relationship to suicide. Increased VDR and decreased CRAMP expression are consistent with previously reported associations between vitamin D deficiency, immune dysregulation, and suicidal behavior, and should lead to future studies uncovering novel interactive targets for suicide prevention.

Prevention and management of glucocorticoid-induced side effects: A comprehensive review: A review of glucocorticoid pharmacology and bone health

Systemic glucocorticoids are an essential therapy for a range of conditions, but their multiple side effects can produce significant morbidity for patients. The objective of this review is to discuss these side effects while addressing 3 questions: 1) What dose and duration of glucocorticoid therapy should prompt concern for individual side effects?; 2) How should clinicians counsel patients about these complications?; and 3) How can these problems be prevented or managed? To accomplish these objectives, we have created a series of tables and algorithms based on a review of relevant data to guide counseling, prophylaxis, and management of 11 glucocorticoid side effects. The first article in this 4-part continuing medical education series begins with a review of glucocorticoid pharmacology followed by a discussion of bone health (ie, osteoporosis and osteonecrosis).

Bone density is normal and does not change over 2 years in sarcoidosis

SUMMARY

Small studies have previously suggested that sarcoidosis may be associated with low bone mineral density. In this observational study of 64 patients with sarcoidosis, bone mineral density was within the normal range at baseline, and there was no evidence of accelerated bone loss over 1-2 years.

INTRODUCTION

Several small studies have suggested that sarcoidosis may be associated with low bone mineral density (BMD).

METHODS

We undertook a cross-sectional study of BMD in 64 patients with sarcoidosis. Of these, 27 with 25-hydroxyvitamin D<50 nmol/L entered a 1-year intervention study of vitamin D supplements, and 37 entered a 2-year longitudinal study of BMD, with the primary endpoint of the change in lumbar spine BMD.

RESULTS

The mean age of participants was 58 years, 68% were female, and 8% were currently using oral glucocorticoids. At baseline, BMD for the entire cohort was greater than the expected values for the population at the lumbar spine (mean Z-score 0.7, P<0.001) and total body (0.5, P<0.001) and similar to expected values at the femoral neck (0.2, P=0.14) and total hip (0.2, P=0.14). BMD did not change at any of these four sites (P>0.19) over 2 years in the longitudinal study. In the intervention study, vitamin D supplements had no effect on BMD, and therefore we pooled the data from all participants. BMD did not change over 1 year at the spine, total hip, or femoral neck (P>0.3), but decreased by 0.7% (95% confidence interval 0.3-1.1) at the total body (P=0.019).

CONCLUSIONS

BMD was normal at baseline, and there was no consistent evidence of accelerated bone loss over 1-2 years, regardless of baseline vitamin D status. Patients with sarcoidosis not using oral glucocorticoids do not need routine monitoring of BMD.

A practical approach to cutaneous sarcoidosis

Sarcoidosis is a chronic inflammatory disorder that has the potential to affect multiple organs, including the skin. Its cutaneous manifestations are varied and can provide clues to underlying systemic manifestations. Unfortunately, they also can be disfiguring. Therapy is usually directed at the organ system most severely affected, which often may help cutaneous disease. However, cutaneous disease may be recalcitrant to treatment directed at extracutaneous disease, or it may be severe enough to require targeted therapy. This article focuses on the dermatologist's role in recognizing and diagnosing cutaneous sarcoidosis, evaluating patients for systemic disease involvement, and treating the skin manifestations of sarcoidosis.

Randomised controlled trial of vitamin D supplementation in sarcoidosis

OBJECTIVES

The role vitamin D intake/production plays in sarcoidosis-associated hypercalcaemia is uncertain. However, authoritative reviews have recommended avoiding sunlight exposure and vitamin D supplements, which might lead to adverse skeletal outcomes from vitamin D insufficiency. We investigated the effects of vitamin D supplementation on surrogate measures of skeletal health in patients with sarcoidosis and vitamin D insufficiency.

DESIGN

Randomised, placebo-controlled trial.

SETTING

Clinical research centre.

PARTICIPANTS

27 normocalcaemic patients with sarcoidosis and 25-hydroxyvitamin D (25OHD) <50 nmol/L.

INTERVENTION

50 000 IU weekly cholecalciferol for 4 weeks, then 50 000 IU monthly for 11 months or placebo.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary endpoint was the change in serum calcium over 12 months, and secondary endpoints included measurements of calcitropic hormones, bone turnover markers and bone mineral density (BMD).

RESULTS

The mean age of participants was 57 years and 70% were women. The mean (SD) screening 25OHD was 35 (12) and 38 (9) nmol/L in the treatment and control groups, respectively. Vitamin D supplementation increased 25OHD to 94 nmol/L after 4 weeks, 84 nmol/L at 6 months and 78 nmol/L at 12 months, while levels remained stable in the control group. 1,25-Dihydroxy vitamin D levels were significantly different between the groups at 4 weeks, but not at 6 or 12 months. There were no between-groups differences in albumin-adjusted serum calcium, 24 h urine calcium, markers of bone turnover, parathyroid hormone or BMD over the trial. One participant developed significant hypercalcaemia after 6 weeks (total cholecalciferol dose 250 000 IU).

CONCLUSIONS

In patients with sarcoidosis and 25OHD <50 nmol/L, vitamin D supplements did not alter average serum calcium or urine calcium, but had no benefit on surrogate markers of skeletal health and caused one case of significant hypercalcaemia.

TRIAL REGISTRATION

This trial is registered at the Australian New Zealand Clinical Trials Registry (http://www.anzctr.org.au). The registration number is ACTRN12607000364471, date of registration 5/7/2007.

Vitamin D in cutaneous carcinogenesis: part II

The role of vitamin D in health maintenance and disease prevention in fields ranging from bone metabolism to cancer is currently under intensive investigation. A number of epidemiologic studies have suggested that vitamin D may have a protective effect on cancer risk and cancer-associated mortality. With regard to skin cancer, epidemiologic and laboratory studies suggest that vitamin D and its metabolites may have a similar risk reducing effect. Potential mechanisms of action include inhibition of the hedgehog signaling pathway and upregulation of nucleotide excision repair enzymes. The key factor complicating the association between vitamin D and skin cancer is ultraviolet B radiation. The same spectrum of ultraviolet B radiation that catalyzes the production of vitamin D in the skin also causes DNA damage that can lead to epidermal malignancies. Part II of this continuing medical education article will summarize the literature on vitamin D and skin cancer to identify evidence-based optimal serum levels of vitamin D and to recommend ways of achieving those levels while minimizing the risk of skin cancer.

Fecal microbiota transplantation in relapsing Clostridium difficile infection

Clostridium difficile infection rates are Climbing in frequency and severity, and the spectrum of susceptible patients is expanding beyond the traditional scope of hospitalized patients receiving antibiotics. Fecal microbiota transplantation is becoming increasingly accepted as an effective and safe intervention in patients with recurrent disease, likely due to the restoration of a disrupted microbiome. Cure rates of > 90% are being consistently reported from multiple centers. Transplantation can be provided through a variety of methodologies, either to the lower proximal, lower distal, or upper gastrointestinal tract. This review summarizes reported results, factors in donor selection, appropriate patient criteria, and the various preparations and mechanisms of fecal microbiota transplant delivery available to clinicians and patients.

A dermatologist's perspective on vitamin D

Vitamin D is a fat-soluble steroid hormone that is crucial for human health and has recently generated controversy regarding its role in human health and disease. In this Special Article, we discuss our dermatologic perspective on vitamin D in a question-and-answer format. We discuss methods of obtaining vitamin D, including cutaneous photobiosynthesis, diet, and supplements and include the recent US Institute of Medicine recommendations. Other reviewed topics include the associations among skin pigmentation, climate, photoprotection, and vitamin D levels. We also elaborate on the popular interest in sun exposure as a method of normalizing vitamin D levels in the context of the risks of solar and artificial radiation. We also discuss groups at risk for vitamin D inadequacy, the need for testing serum vitamin D levels, and the role of phototherapy in patients with malabsorption conditions and hypervitaminosis D, with a focus on patients with sarcoidosis. Finally, we summarize our recommendations on vitamin D.