Vitamin D-Mediated Hypercalcemia: Mechanisms, Diagnosis, and Treatment

Vitamin D Toxicity Presenting as Altered Mental Status in Elderly Patients

Background and objective  Around 25-30% of elderly patients present to emergency departments (ED) with altered mental status (AMS), with hypercalcemia being one of the metabolic causes. Elderly patients, due to their multiple vulnerability factors and relative homeostenosis, are susceptible to alterations in mental state at even milder grades of hypercalcemia. There is a trend of overzealous prescription of higher doses of vitamin D in elderly patients for various ailments, which often exceeds the requirements of the patients. In this study, we aimed to establish vitamin D toxicity (VDT) as an underlying cause of AMS in elderly patients presenting to the hospital. Methods This was a descriptive case study conducted at a tertiary care university hospital in North India, from January 2015 to March 2020 for a total duration of five years. Elderly patients (aged ≥60 years) who were admitted with VDT as a cause for underlying hypercalcemia were included. The evaluation included patient history regarding the dosage of vitamin D received, route of administration, and biochemical parameters, such as serum calcium, intact parathyroid hormone (iPTH), 25-hydroxy vitamin D [25(OH)D], and albumin. All other potential causes for hypercalcemia and AMS were ruled out concurrently. Results A total of 19 patients were enrolled in the study, with a mean age of 72.3 years (range: 62-86 years). All patients had received injectable vitamin D formulation. The mean serum calcium among the patients was 12.52 ± 1.12 mg/dL (range: 11.2-15.7 mg/dL), whereas the mean 25(OH)D was 196.34 ± 70.44 ng/mL (range: 107-356 ng/mL). The mean cumulative vitamin D supplement intake was 2.594 ± 0.841 million IU (range: 1.2 million-4.2 million IU). While six patients had mild hypercalcemia, 12 had moderate, and one person had severe hypercalcemia, with altered sensorium (85%) being the most common complaint for presenting to ED, followed by generalized weakness (15%). Conclusion VDT can manifest with AMS as an initial presenting complaint. The geriatric population, due to various underlying vulnerability factors, is more susceptible than their younger counterparts. We strongly recommend that in elderly patients, higher doses of vitamin D should be prescribed only after checking their serum levels, and frequent monitoring of vitamin D should be performed.

Mechanisms of action of vitamin D in delaying aging and preventing disease by inhibiting oxidative stress

Although several recent studies have shown that vitamin D supplementation beneficially decreases oxidative stress parameters, there is no consensus on this subject in humans. Thus the role of vitamin D supplementation has recently become a controversial topic because large intervention studies in humans have not shown significant benefits. These studies have indicated that supplementation with precursor forms of active vitamin D has no effect on all-cause mortality, cannot reduce the fracture risk of the elderly, cannot reduce the incidence of cancer or cardiovascular disease in the elderly, and cannot significantly reduce the incidence risk of diabetes in the elderly. However, a link between several age-related diseases and enhanced oxidative stress has been found in mice with insufficient or deficient 1,25-dihydroxyvitamin D (1,25(OH)₂D), the active form of vitamin D, which indicates that reduced active vitamin D accelerates aging and age-related diseases by increasing oxidative stress. Furthermore, supplementation of exogenous 1,25(OH)₂D₃, or antioxidants, could dramatically postpone aging, prevent osteoporosis and spontaneous tumor development induced by 1,25(OH)₂D insufficiency or deficiency, by inhibiting oxidative stress. Mechanistically, the antioxidative effects of 1,25(OH)₂D₃ are carried out via the vitamin D receptor (VDR) by activation of the Nrf2 oxidative stress response pathway though transcriptional or posttranscriptional activation of Nrf2 or transcriptional upregulation of Sirt1 and Bmi1 expression. Whether discrepancies between studies in humans and in mice reflect the different forms of vitamin D examined remains to be determined.

Effect of vitamin D supplementation on brain waves, behavioral performance, nitric oxide, malondialdehyde, and high-sensitivity C-reactive protein in children with attention deficit/hyperactivity disorder: study protocol for a randomized clinical trial

Background

Attention deficit/hyperactivity disorder (ADHD) is the most common chronic mental and behavioral disorder among children. Some studies showed the lower levels of vitamin D in patients with ADHD compared with the healthy people. Few clinical trials were conducted in this field. The present study will be performed to examine the effect of vitamin D supplementation in children with ADHD.

Methods

We will conduct a double-blind, randomized controlled clinical trial to investigate the effect of vitamin D supplementation on brain waves, behavioral performance, serum nitric oxide, malondialdehyde, and high-sensitivity C-reactive protein in 50 patients with ADHD. The intervention group will receive one capsule 50,000 IU vitamin D every week, for 8 weeks. The control group will receive one placebo capsule containing 1000 mg olive oil every week. Electroencephalography will be performed for 10 min using Brain Master Discovery from 19 scalp sites both before the first intervention and the 10 sessions of the therapy. The artifact-free periods of 1-min electroencephalography data will be analyzed for quantitative electroencephalography measures.

Discussion

For the first time, this clinical trial will evaluate the effect of vitamin D supplementation on brain waves, serum nitric oxide, malondialdehyde, and high-sensitivity C-reactive protein in patients with ADHD. The results of the present clinical trial will provide a better vision about the vitamin D efficacy in patients with ADHD.

Trial registration

Registered on 5 November 2020 at Iranian Registry of Clinical Trials with code number IRCT20200922048802N1 (https://www.irct.ir/trial/51410).

Vitamin D and the Central Nervous System: Causative and Preventative Mechanisms in Brain Disorders

Twenty of the last one hundred years of vitamin D research have involved investigations of the brain as a target organ for this hormone. Our group was one of the first to investigate brain outcomes resulting from primarily restricting dietary vitamin D during brain development. With the advent of new molecular and neurochemical techniques in neuroscience, there has been increasing interest in the potential neuroprotective actions of vitamin D in response to a variety of adverse exposures and how this hormone could affect brain development and function. Rather than provide an exhaustive summary of this data and a listing of neurological or psychiatric conditions that vitamin D deficiency has been associated with, here, we provide an update on the actions of this vitamin in the brain and cellular processes vitamin D may be targeting in psychiatry and neurology.

[Hypercalcemia - Diagnosis and Management]

Hypercalcemia - Diagnosis and Management Abstract. The diagnostic workup of hypercalcemia requires a thorough patient history, a focused clinical examination as well as a step-by-step laboratory diagnostic approach. In order to detect the exact aetiology of hypercalcemia an accurate measurement of serum calcium in correlation with the parathyroid hormone level is therefore essential. Primary hyperparathyroidism and malignancy-related hypercalcemia are responsible for about 90% of all hypercalcemia cases. Therefore, these two pathologies should always be considered in the diagnostic approach. The therapeutic procedure is based on the aetiology and severity of the hypercalcemia.

Skeletal and extraskeletal disorders of biomineralization

The physiological process of biomineralization is complex and deviation from it leads to a variety of diseases. Progress in the past 10 years has enhanced understanding of the genetic, molecular and cellular pathophysiology underlying these disorders; sometimes, this knowledge has both facilitated restoration of health and clarified the very nature of biomineralization as it occurs in humans. In this Review, we consider the principal regulators of mineralization and crystallization, and how dysregulation of these processes can lead to human disease. The knowledge acquired to date and gaps still to be filled are highlighted. The disorders of mineralization discussed comprise a broad spectrum of conditions that encompass bone disorders associated with alterations of mineral quantity and quality, as well as disorders of extraskeletal mineralization (hyperphosphataemic familial tumoural calcinosis). Included are disorders of alkaline phosphatase (hypophosphatasia) and phosphate homeostasis (X-linked hypophosphataemic rickets, fluorosis, rickets and osteomalacia). Furthermore, crystallopathies are covered as well as arterial and renal calcification. This Review discusses the current knowledge of biomineralization derived from basic and clinical research and points to future studies that will lead to new therapeutic approaches for biomineralization disorders.

Beta-caryophyllene prevents the defects in trabecular bone caused by Vitamin D deficiency through pathways instated by increased expression of klotho

Aims

This study investigated the effects of β-caryophyllene (BCP) on protecting bone from vitamin D deficiency in mice fed on a diet either lacking (D-) or containing (D+) vitamin D.

Methods

A total of 40 female mice were assigned to four treatment groups (n = 10/group): D+ diet with propylene glycol control, D+ diet with BCP, D-deficient diet with control, and D-deficient diet with BCP. The D+ diet is a commercial basal diet, while the D-deficient diet contains 0.47% calcium, 0.3% phosphorus, and no vitamin D. All the mice were housed in conditions without ultraviolet light. Bone properties were evaluated by X-ray micro-CT. Serum levels of klotho were measured by enzyme-linked immunosorbent assay.

Results

Under these conditions, the D-deficient diet enhanced the length of femur and tibia bones (p < 0.050), and increased bone volume (BV; p < 0.010) and trabecular bone volume fraction (BV/TV; p < 0.010) compared to D+ diet. With a diet containing BCP, the mice exhibited higher BV and bone mineral density (BMD; p < 0.050) than control group. The trabecular and cortical bone were also affected by vitamin D and BCP. In addition, inclusion of dietary BCP improved the serum concentrations of klotho (p < 0.050). In mice, klotho regulates the expression level of cannabinoid type 2 receptor (Cnr2) and fibroblast growth factor 23 (Fgf23) through CD300a. In humans, data suggest that klotho is connected to BMD. The expression of klotho is also associated with bone markers.

Conclusion

These data indicate that BCP enhances the serum level of klotho, leading to improved bone properties and mineralization in an experimental mouse model.

Cite this article: Bone Joint Res 2022;11(8):528–540.

Stimulation of osteoclast formation and bone resorption by glucocorticoids: Synergistic interactions with the calcium regulating hormones parathyroid hormone and 1,25(OH)2-vitamin D3

Osteoporosis is a significant health problem, with skeletal fractures increasing morbidity and mortality. Excess glucocorticoids (GC) represents the leading cause of secondary osteoporosis. The first phase of glucocorticoid-induced osteoporosis is increased bone resorption. In this Chapter, in vitro studies of the direct glucocorticoid receptor (GR) mediated cellular effects of GC on osteoclasts to affect bone resorption and indirect effects on osteoblast lineage cells to increase the RANKL/OPG ratio and stimulate osteoclastogenesis and bone resorption are reviewed in detail, together with detailed descriptions of in vivo effects of GC in different portions of the skeleton in research animals and humans. Brief sections are devoted to contrasting functions of GC in osteonecrosis, vitamin D formation, in vitro and in vivo bone resorptive actions dependent on vitamin D receptor and vitamin D toxicity, as well as the molecular basis of GR action. Included are also more detailed assessments of the interactions of GC with the major calcium regulating hormones, 1,25(OH)₂-vitamin D3 and parathyroid hormone, describing the in vitro increases in RANKL/OPG ratios, osteoclastogenesis and synergistic bone resorption that occurs when GC is combined with either 1,25(OH)₂-vitamin D3 or parathyroid hormone. Additionally, a molecular basic for the synergistic interaction of GC with 1,25(OH)₂-vitamin D3 is provided along with a suggested molecular basic for the interaction between GC and parathyroid hormone.

Gene-Regulatory Potential of 25-Hydroxyvitamin D3 and D2

Human peripheral blood mononuclear cells (PBMCs) represent a highly responsive primary tissue that is composed of innate and adaptive immune cells. In this study, we compared modulation of the transcriptome of PBMCs by the vitamin D metabolites 25-hydroxyvitamin D₃ (25(OH)D₃), 25(OH)D₂ and 1α,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃). Saturating concentrations of 1,25(OH)₂D₃, 25(OH)D₃ and 25(OH)D₂ resulted after 24 h stimulation in a comparable number and identity of target genes, but below 250 nM 25(OH)D₃ and 25(OH)D₂ were largely insufficient to affect the transcriptome. The average EC₅₀ values of 206 common target genes were 322 nM for 25(OH)D₃ and 295 nM for 25(OH)D₂ being some 600-fold higher than 0.48 nM for 1,25(OH)₂D₃. The type of target gene, such as primary/secondary, direct/indirect or up-/down-regulated, had no significant effect on vitamin D metabolite sensitivity, but individual genes could be classified into high, mid and lower responders. Since the 1α-hydroxylase CYP27B1 is very low expressed in PBMCs and early (4 and 8 h) transcriptome responses to 25(OH)D₃ and 25(OH)D₂ were as prominent as to 1,25(OH)₂D₃, both vitamin D metabolites may directly control gene expression. In conclusion, at supra-physiological concentrations 25(OH)D₃ and 25(OH)D₂ are equally potent in modulating the transcriptome of PBMCs possibly by directly activating the vitamin D receptor.

Regulation of 1 and 24 hydroxylation of vitamin D metabolites in the proximal tubule

Calcium and phosphate are critical for numerous physiological processes. Consequently, the plasma concentration of these ions are tightly regulated. Calcitriol, the active form of vitamin D, is a positive modulator of mineralization as well as calcium and phosphate metabolism. The molecular and physiological effects of calcitriol are well documented. Calcitriol increases blood calcium and phosphate levels by increasing absorption from the intestine, and resorption of bone. Calcitriol synthesis is a multistep process. A precursor is first made via skin exposure to UV, it is then 25-hydroxylated in the liver to form 25-hydroxyitamin D. The next hydroxylation step occurs in the renal proximal tubule via the 1-αhydroxylase enzyme (encoded by CYP27B1) thereby generating 1,25-dihydroxyvitamin D, that is, calcitriol. At the same site, the 25-hydroxyvitamin D 24-hydroxlase enzyme encoded by CYP24A1 can hydroxylate 25-hydroxyvitamin D or calcitriol to deactivate the hormone. Plasma calcitriol levels are primarily determined by the regulated expression of CYP27B1 and CYP24A1. This occurs in response to parathyroid hormone (increases CYP27B1), calcitriol itself (decreases CYP27B1 and increases CYP24A1), calcitonin (increases or decreases CYP24A1 and increases CYP27B1), FGF23 (decreases CYP27B1 and increases CYP24A1) and potentially plasma calcium and phosphate levels themselves (mixed effects). Herein, we review the regulation of CYP27B1 and CYP24A1 transcription in response to the action of classic phophocalciotropic hormones and explore the possibility of direct regulation by plasma calcium.

Effect of vitamin D monotherapy on indices of sarcopenia in community-dwelling older adults: a systematic review and meta-analysis

BACKGROUND

Vitamin D supplementation is proposed as a potentially effective nutritional intervention to mitigate the risk of sarcopenia. The aim of this systematic review and meta-analysis was to investigate the impact of vitamin D supplementation monotherapy on indices of sarcopenia in community-dwelling older adults.

METHODS

A comprehensive search of the literature was conducted in PubMed, Web of Science, Scopus, and Cochrane Library. Eligible randomized controlled trials (RCTs) compared the effect of vitamin D supplementation (as monotherapy) with placebo on indices of sarcopenia in older (>50 years) adults. Using the random effects inverse-variance model, we calculated the mean difference (MD) in handgrip strength (HGS), short physical performance battery (SPPB), timed up and go (TUG), and appendicular lean mass (ALM) between groups. We also calculated the standardized mean difference (SMD) in general muscle strength and general physical performance (composite plot of all muscle strength and physical performance outcomes, respectively) between groups.

RESULTS

Ten RCTs were included in the meta-analysis. A significant decrease in SPPB scores was observed with vitamin D supplementation compared with placebo (MD: -0.23; 95% CI -0.40 to -0.06; I²  = 0%; P = 0.007). Vitamin D supplementation conferred no effect on HGS (MD: -0.07 kg; 95% CI -0.70 to 0.55; I²  = 51%, P = 0.82), TUG (MD: 0.07 s; 95% CI -0.08 to 0.22; I²  = 0%, P = 0.35), ALM (MD: 0.06 kg/m² ; 95% CI: -0.32 to 0.44; I²  = 73%, P = 0.77), general muscle strength (SMD: -0.01; 95% CI -0.17 to 0.15; I²  = 42%, P = 0.90), or general physical performance (SMD: -0.02; 95% CI -0.23 to 0.18; I²  = 71%, P = 0.83).

CONCLUSIONS

Vitamin D supplementation did not improve any sarcopenia indices in community-dwelling older adults and may compromise some aspects of physical performance. Future studies are warranted to investigate the impact of vitamin D supplementation on individual indices of SPPB, including mobility and balance, in older adults.

Hypercalcemia - An enigmatic cause of acute pancreatitis

Background

Acute pancreatitis (AP) continues to be one of the common abdominal emergencies encountered in tertiary care hospitals. The majority of AP is caused by gall stones and alcohol. Hypercalcemia though uncommon has been reported to cause AP, recurrent AP, and chronic pancreatitis (CP).

Aim

The aim of this study was to describe hypercalcemia-induced AP in different settings.

Materials and Methods

In total 100 patients with AP, admitted from January 2021 to December 2021 at our center, etiologies were biliary (36%), alcohol (19%), idiopathic (21%), alcohol plus Biliary (5%), post-endoscopic retrograde cholangiopancreaticography (7%), drug-induced (6%), hypercalcemia (3%), and dengue infection (3%). Overall mortality was 11%.

Results

In three patients with hypercalcemia-induced pancreatitis, causes of hypercalcemia were multiple myeloma, parathyroid adenoma leading to hyperparathyroidism, and hypervitaminosis D in association with hyperthyroidism.

Conclusion

Hypercalcemia-induced AP is not a rare phenomenon and should be actively investigated to prevent further attacks of AP and progression to CP.

Relevance for Patients

Hypercalcemia is a potentially treatable cause of AP and its identification will not only help to treat and prevent further episodes of pancreatitis but also to manage underlying diseases leading to hypercalcemia.

Pharmacologic conversion of cancer-associated fibroblasts from a protumor phenotype to an antitumor phenotype improves the sensitivity of pancreatic cancer to chemotherapeutics

Previous therapeutic attempts to deplete cancer-associated fibroblasts (CAFs) or inhibit their proliferation in pancreatic ductal adenocarcinoma (PDAC) were not successful in mice or patients. Thus, CAFs may be tumor suppressive or heterogeneous, with distinct cancer-restraining and -promoting CAFs (rCAFs and pCAFs, respectively). Here, we showed that induced expression of the glycosylphosphatidylinositol-anchored protein Meflin, a rCAF-specific marker, in CAFs by genetic and pharmacological approaches improved the chemosensitivity of mouse PDAC. A chemical library screen identified Am80, a synthetic, nonnatural retinoid, as a reagent that effectively induced Meflin expression in CAFs. Am80 administration improved the sensitivity of PDAC to chemotherapeutics, accompanied by increases in tumor vessel area and intratumoral drug delivery. Mechanistically, Meflin was involved in the suppression of tissue stiffening by interacting with lysyl oxidase to inhibit its collagen crosslinking activity. These data suggested that modulation of CAF heterogeneity may represent a strategy for PDAC treatment.

Effects of Hypocalcemic Vitamin D Analogs in the Expression of DNA Damage Induced in Minilungs from hESCs: Implications for Lung Fibrosis

In our previous work, we evaluated the therapeutic effects of 1α,25-Dihydroxyvitamin D₃, the biologically active form of vitamin D, in the context of bleomycin-induced lung fibrosis. Contrary to the expected, vitamin D supplementation increased the DNA damage expression and cellular senescence in alveolar epithelial type II cells and aggravated the overall lung pathology induced in mice by bleomycin. These effects were probably due to an alteration in the cellular DNA double-strand breaks’ repair capability. In the present work, we have evaluated the effects of two hypocalcemic vitamin D analogs (calcipotriol and paricalcitol) in the expression of DNA damage in the context of minilungs derived from human embryonic stem cells and in the cell line A549.

Novel DNA Aptamer for CYP24A1 Inhibition with Enhanced Antiproliferative Activity in Cancer Cells

Overexpression of the vitamin D3-inactivating enzyme CYP24A1 (cytochrome P450 family 24 subfamily and hereafter referred to as CYP24) can cause chronic kidney diseases, osteoporosis, and several types of cancers. Therefore, CYP24 inhibition has been considered a potential therapeutic approach. Vitamin D3 mimetics and small molecule inhibitors have been shown to be effective, but nonspecific binding, drug resistance, and potential toxicity limit their effectiveness. We have identified a novel 70-nt DNA aptamer-based inhibitor of CYP24 by utilizing the competition-based aptamer selection strategy, taking CYP24 as the positive target protein and CYP27B1 (the enzyme catalyzing active vitamin D3 production) as the countertarget protein. One of the identified aptamers, Apt-7, showed a 5.8-fold higher binding affinity with CYP24 than the similar competitor CYP27B1. Interestingly, Apt-7 selectively inhibited CYP24 (the relative CYP24 activity decreased by 39.1 ± 3% and showed almost no inhibition of CYP27B1). Furthermore, Apt-7 showed cellular internalization in CYP24-overexpressing A549 lung adenocarcinoma cells via endocytosis and induced endogenous CYP24 inhibition-based antiproliferative activity in cancer cells. We also employed high-speed atomic force microscopy experiments and molecular docking simulations to provide a single-molecule explanation of the aptamer-based CYP24 inhibition mechanism. The novel aptamer identified in this study presents an opportunity to generate a new probe for the recognition and inhibition of CYP24 for biomedical research and could assist in the diagnosis and treatment of cancer.

A brief review of vitamin D as a potential target for the regulation of blood glucose and inflammation in diabetes-associated periodontitis

Diabetes is a metabolic disorder associated with various complications, including periodontitis. The risk of periodontitis is increased in patients with diabetes, while vitamin D deficiency is associated with both diabetes and periodontitis. Thus, there is a need to identify the molecular effects of vitamin D on the regulation of inflammation and glucose in diabetes-associated periodontitis. The Web of Science, Scopus, and PubMed databases were searched for studies of the molecular effects of vitamin D. Molecular effects were reportedly mediated by salivary secretions, interactions of advanced glycation end products (AGEs) with receptors of AGEs (RAGEs), cytokines, and oxidative stress pathways linking diabetes with periodontitis. Vitamin D supplementation attenuates inflammation in diabetes-associated periodontitis by reducing the levels of inflammatory cytokines and numbers of immune cells; it also has antibacterial effects. Vitamin D reduces cytokine levels through regulation of the extracellular signal-related kinase 1/2 and Toll-like receptor 1/2 pathways, along with the suppression of interleukin expression. Glucose homeostasis is altered in diabetes either because of reduced insulin production or decreased insulin sensitivity. These vitamin D-related alterations of glucoregulatory factors may contribute to hyperglycaemia; hyperglycaemia may also lead to alterations of glucoregulatory factors. This review discusses the pathways involved in glucose regulation and effects of vitamin D supplementation on glucose regulation. Further studies are needed to characterise the effects of vitamin D on diabetes-associated periodontitis.

The genetics of kidney stone disease and nephrocalcinosis

Kidney stones (also known as urinary stones or nephrolithiasis) are highly prevalent, affecting approximately 10% of adults worldwide, and the incidence of stone disease is increasing. Kidney stone formation results from an imbalance of inhibitors and promoters of crystallization, and calcium-containing calculi account for over 80% of stones. In most patients, the underlying aetiology is thought to be multifactorial, with environmental, dietary, hormonal and genetic components. The advent of high-throughput sequencing techniques has enabled a monogenic cause of kidney stones to be identified in up to 30% of children and 10% of adults who form stones, with ~35 different genes implicated. In addition, genome-wide association studies have implicated a series of genes involved in renal tubular handling of lithogenic substrates and of inhibitors of crystallization in stone disease in the general population. Such findings will likely lead to the identification of additional treatment targets involving underlying enzymatic or protein defects, including but not limited to those that alter urinary biochemistry.

High-Performance, Nitrogen-Doped, Carbon-Nanotube-Based Electrochemical Sensor For Vitamin D3 Detection

With the fast changing lifestyle, vitamin D deficiency is becoming extremely common. Therefore, development of economical, efficient, and fast sensors for vitamin D is the need of the hour. Carbon-based nanomaterials are extensively explored in sensing of variety of biomolecules. In the present study, an antibody-free, highly sensitive, carbon-nanotube-based, highly responsive vitamin D3 sensor is reported. Nitrogen-doped carbon nanotubes are utilized to overcome the limiting factor of hydrophobic character of pure carbon. The synthesized N-doped CNTs showed a specific surface area of 24 m²/g. The surface charges of vitamin D3 and the vitamin D3/NCNT complex are found to be -20 and -6.4 mV, respectively, by zeta potential measurements. The sensor is able to deliver high performance in the concentration range of 0-10 nM, with a limit of detection of 16 pM. The response study indicated the sensitivity value as 0.000495 mA/cm² nM. The sensor is also able to show a higher selectivity toward vitamin D3 in comparison to other biomolecules. The long-term stability, reproducibility, good linear range, and ultralow detection capability of the sensor are also reported.

Vitamin d-fortified bread: Systematic review of fortification approaches and clinical studies

Vitamin d-fortified bread has been proposed as a strategy to increase the average daily intake and serum status of this nutrient. This review aimed to bring together the different types of scientific articles on vitamin d-fortified bread. The databases used for the research were PUBMED, WEB of SCIENCE and SCOPUS; all original indexed studies written in English, published between January 2000 and March 2021, were considered. Three important points were identified: i) theoretical models of fortification; ii) stability, bioaccessibility, and bioavailability studies of vitamin d-fortified breads; and iii) clinical effects of vitamin d-fortified breads. This review showed that vitamin d-fortified bread is a promising vehicle for fortification strategy effects, leading to increased serum concentrations of 25(OH)D and decreased parathyroid hormone. However, further studies are needed to elucidate the effects and effectiveness of this fortification strategy in the prevention/treatment of vitamin D deficiency.

100 YEARS OF VITAMIN D: Supraphysiological doses of vitamin D changes brainwave activity patterns in rats

Low plasma levels of vitamin D causes bone mineral change that can precipitate osteopenia and osteoporosis and could aggravate autoimmune diseases, hypertension and diabetes. The demand for vitamin D supplementation becomes necessary; however, the consumption of vitamin D is not without risks, which its toxicity could have potentially serious consequences related to hypervitaminosis D, such as hypercalcemia and cerebral alterations. Thus, the present study describes the electroencephalographic changes caused by supraphysiological doses of vitamin D in the brain electrical dynamics and the electrocardiographic changes. After 4 days of treatment with vitamin D at a dose of 25,000 IU/kg, the serum calcium levels found were increased in comparison with the control group. The electrocorticogram analysis found a reduction in wave activity in the delta, theta, alpha and beta frequency bands. For ECG was observed changes with shortened QT follow-up, which could be related to serum calcium concentration. This study presented important evidence about the cerebral and cardiac alterations caused by high doses of vitamin D, indicating valuable parameters in the screening and decision-making process for diagnosing patients with symptoms suggestive of intoxication.

Case Report: Acute Kidney Injury Due to Chronic Milk-Alkali Syndrome in a Patient With Colon Cancer

Background

Common causes of hypercalcemia include primary hyperparathyroidism and paraneoplastic syndrome of malignancy. Because of this, physicians can easily miss extrinsic causes of hypercalcemia such as milk-alkali syndrome in patients with cancer. We successfully treated a case of acute kidney injury due to severe hypercalcemia caused by milk-alkali syndrome due to long-term milk drinking in a patient with colon cancer.

Case Description

A 62-year-old man was referred to nephrology for hypercalcemia and azotemia that was found during preoperative evaluation for colon cancer surgery. The patient had experienced several months of dizziness and anorexia. We started hemodialysis because hypercalcemia and azotemia were not improved despite large amounts of hydration and diuretics. We suspected paraneoplastic syndrome because of concomitant colon cancer and low intact parathyroid hormone (PTH). Renal microcalcifications were observed on ultrasonography. Metastatic calcifications of the lung and stomach were present, but no malignant metastasis appeared on bone scans. There was no evidence of metastatic malignant lesions on chest or abdominal enhanced computed tomography. PTH-related peptide was not detected. Thus, other causes of hypercalcemia beyond malignancy were considered. On history-taking, the patient reported consuming 1,000 to 1,200 mL of milk daily for the prior 3 months. Hypercalcemia was due to chronic milk-alkali syndrome. We advised withdrawal of milk and nutritional pills. Hemodialysis was stopped after 2 weeks since azotemia and hypercalcemia were resolving. Acute kidney injury was improved, and mild hypercalcemia remained when he underwent hemicolectomy after 1 month. Thereafter, serum calcium and creatinine remained normal at discharge and follow-up for 1 year in the outpatient clinic. However, lung calcifications still remained on bone scan after 1 year.

Conclusions

Chronic milk-alkali syndrome is a rare condition resulting from excessive calcium and alkali intake through various routes, like milk, nutritional supplements, and medicines for osteoporosis. Therefore, early management for hypercalcemia should include precise history taking including diet, previous diagnoses, and current medications.

99mTc-MDP Bone Scintigraphy and SPECT/CT of Extensive Subcutaneous Calcification in the Setting of Cosmetic-Induced Lipogranulomatosis

ABSTRACT

A 56-year-old woman with history of cosmetic buttock augmentation via mineral oil injection 20+ years ago presented with extensive abdominopelvic skin induration and hypercalcemia. The 99mTc-MDP bone scintigraphy performed for hypercalcemia revealed marked heterogeneous radiotracer activity partially obscuring the skeleton. Subsequent SPECT/CT demonstrated that the radiotracer activity was associated with exclusively subcutaneous calcification, the extent of which far exceeded the originally augmented gluteal regions. After extensive workup including tissue biopsy, the final diagnosis was subcutaneous calcification and hypercalcemia secondary to cosmetic injection-related sclerosing lipogranulomatosis, which is a very rare complication of cosmetic augmentation.

Vitamin D attenuates COVID-19 complications via modulation of proinflammatory cytokines, antiviral proteins, and autophagy

INTRODUCTION

Global emergence of coronavirus disease-19 (COVID-19) has clearly shown variable severity, mortality, and frequency between and within populations worldwide. These striking differences have made many biological variables attractive for future investigations. One of these variables, vitamin D, has been implicated in COVID-19 with rapidly growing scientific evidence.

AREAS COVERED

The review intended to systematically explore the sources, and immunomodulatory role of vitamin D in COVID-19. Search engines and data sources including Google Scholar, PubMed, NCBI, Scopus, and Web of Science were used for data collection. The search terms used were Vitamin D, COVID-19, immune system, and antiviral mechanism. Overall, 232 sources of information were collected and 188 were included in this review.

EXPERT OPINION

Interaction of vitamin D and vitamin D receptor (VDR) triggers the cellular events to modulate the immune system by regulation of many genes. Vitamin D operates as a double-edged sword against COVID-19. First, in macrophages, it promotes the production of antimicrobial and antiviral proteins like β-defensin 2 and cathelicidin, and these proteins inhibit the replication of viral particles and promote the clearance of virus from the cells by autophagy. Second, it suppresses cytokine storm and inflammatory processes in COVID-19.

CYP24A1 and SLC34A1 Pathogenic Variants Are Uncommon in a Canadian Cohort of Children with Hypercalcemia or Hypercalciuria

OBJECTIVES

Biallelic pathogenic variants in CYPA24A1 and SLC34A1 are causes of idiopathic infantile hypercalcemia. Pathogenic variants in both may also give rise to hypercalciuria with nephrocalcinosis or nephrolithiasis without previous hypercalcemia (renal group). Our objective was to examine the frequency of CYP24A1 or SLC34A1 variants in children with early hypercalcemia or late-onset hypercalciuria.

METHOD

Forty-one children from 7 centers across Canada were recruited. Local investigations were undertaken. The serum was evaluated by liquid chromatography tandem-mass spectrometry for the ratio of 25-hydroxyvitamin D3 to 24,25-dihydroxyvitamin D3, (25-OH-D3:24,25-(OH)2D3), an elevation pathognomonic for the loss of function of the CYP24A1 enzyme. Mutational analyses were undertaken. Family cascade screening was performed if pathogenic variants were detected in probands.

RESULTS

Twenty-nine children had early-onset hypercalcemia; none had elevated 25-OH-D3:24,25-(OH)2D3 or variants. Interestingly, 2 of 12 in the renal group had elevated 25-OH-D3:24,25-(OH)2D3 and presented as preadolescents. In case 1, cascade testing revealed a sibling and parent with asymptomatic pathogenic variants in CYP24A1. Four CYP24A1 pathogenic variants were identified in these 2 probands: 3 have been described in European populations, and 1 is a rare variant in exon 7 (c931delC) that is likely pathogenic. No SLC34A1 pathogenic variants were detected.

CONCLUSION

In Canada, pathogenic variants in CYP24A1 appear to manifest with late-onset hypercalciuria and its sequelae. The 25-OH-D3:24,25-(OH)2D3 ratio is an excellent tool for screening for biallelic pathogenic variants in CYP24A1. We confirm that cascade testing is important for these variants.

Hypercalcemia Associated with the Ectopic Expression of 25-hydroxyvitamin D3-1α-hydroxylase in Diffuse Large B-cell Lymphoma

An 82-year-old man was transferred to our hospital due to impaired consciousness. His albumin-corrected calcium level was 14.2 mg/dL, intact parathyroid hormone (PTH) and PTH-related protein levels were reduced, and his 1,25-dihydroxyvitamin D [1,25 (OH) ₂VitD] level was elevated at 71.5 pg/mL. Computed tomography revealed masses on the bilateral ribs. The mass on the rib was biopsied and diagnosed as diffuse large B-cell lymphoma (DLBCL). Immunostaining of the biopsy sample with the anti-CYP27B1 antibody revealed the ectopic expression of 1α-hydroxylase in the lesion. We herein report a rare case of hypercalcemia induced by the overproduction of 1,25 (OH) ₂VitD in DLBCL ectopically expressing 1α-hydroxylase.

1,25-Dihydroxyvitamin D3 and 20-Hydroxyvitamin D3 Upregulate LAIR-1 and Attenuate Collagen Induced Arthritis

Vitamin D plays a crucial role in regulation of the immune response. However, treatment of autoimmune diseases with 1,25-dihydroxyvitamin D3 [1,25(OH)₂D3] doses sufficient to be effective is prohibitive due to its calcemic and toxic effects. We use the collagen-induced arthritis (CIA) model to analyze the efficacy of the noncalcemic analog of vitamin D, 20S-hydroxyvitamin D3 [20S(OH)D3], as well as 1,25(OH)₂D3, to attenuate arthritis and explore a potential mechanism of action. Mice fed a diet deficient in vitamin D developed a more severe arthritis characterized by enhanced secretion of T cell inflammatory cytokines, compared to mice fed a normal diet. The T cell inflammatory cytokines were effectively suppressed, however, by culture of the cells with 20S(OH)D3. Interestingly, one of the consequences of culture with 1,25(OH)₂D3 or 20S(OH)D3, was upregulation of the natural inhibitory receptor leukocyte associated immunoglobulin-like receptor-1 (LAIR-1 or CD305). Polyclonal antibodies which activate LAIR-1 were also capable of attenuating arthritis. Moreover, oral therapy with active forms of vitamin D suppressed arthritis in LAIR-1 sufficient DR1 mice, but were ineffective in LAIR-1^−/− deficient mice. Taken together, these data show that the effect of vitamin D on inflammation is at least, in part, mediated by LAIR-1 and that non-calcemic 20S(OH)D3 may be a promising therapeutic agent for the treatment of autoimmune diseases such as Rheumatoid Arthritis.

Safety of Vitamin D Food Fortification and Supplementation: Evidence from Randomized Controlled Trials and Observational Studies

The safety considerations of food-based solutions for vitamin D deficiency prevention, such as fortification and supplementation, are critical. On the basis of collective data from 20 randomized controlled trials (RCTs) and 20 national healthy surveys, as well as prospective cohort studies (PCSs) across the ODIN project (“Food-based solutions for optimal vitamin D nutrition and health through the life cycle”, FP7-613977), we analyzed the potential safety issues arising from vitamin D intakes and/or supplementation. These adverse consequences included high serum 25-hydroxyvitamin D (S-25(OH)D) concentrations (>125 nmol/L), high serum calcium concentrations, and vitamin D intakes in excess of the tolerable upper intake levels (ULs). In the RCTs (n = 3353, with vitamin D doses from 5–175 µg/day), there were no reported adverse effects. The prevalence of high S-25(OH)D was <10% when vitamin D supplements were administered, and <0.1% for fortified foods. Elevated serum calcium was observed among <0.5% in both administration types. No ODIN RCT participants exceeded the age-specific ULs. In observational studies (n = 61,082), the prevalence of high 25(OH)D among children/adolescents, adults, and older adults was <0.3%, with no evidence of adverse effects. In conclusion, high S-25(OH)D concentrations >125 nmol/L were rare in the RCTs and PCSs, and no associated adverse effects were observed.

Drug-Related Hypercalcemia

This review focuses on the commonly prescribed medicaments that can be responsible for hypercalcemia, considering the prevalence, the predominant pathophysiological mechanisms, and the optimal medical management of each drug-induced hypercalcemia. Vitamin D supplements and 1α-hydroxylated vitamin D analogues increase intestinal calcium absorption, renal calcium reabsorption as well as bone resorption. In patients with hypoparathyroidism receiving recombinant human PTH, transient hypercalcemia can occur because of overtreatment, usually during acute illness. Thiazide-induced hypercalcemia is mainly explained by enhanced renal proximal calcium reabsorption, changing preexistent asymptomatic normocalcemic or intermittently hypercalcemic hyperparathyroidism into the classic hypercalcemic hyperparathyroidism. Lithium causes hypercalcemia mainly by drug-induced hyperparathyroidism.

The effect of hypervitaminosis D and intoxication on haematological parameters

BACKGROUND

This study aims to compare the haematological parameters of patients with very high and normal 25-hydroxyvitamin-D3 (25(OH)D3) levels.

METHODS

This study was designed as a retrospective cross-sectional study. The patients were divided into three groups according to their 25(OH)D3 levels: groups 1, 2 and 3 are patients with normal 25(OH)D3 levels (30-88 ng/mL), hypervitaminosis D (89-149 ng/mL) and vitamin D intoxication (>150 ng/mL), respectively. According to vitamin D levels, statistical analysis was performed by comparing the biochemical and haematological data between the groups.

RESULTS

This study evaluated 120 patients (40 patients) in three equal groups. A statistically significant difference was found between the three groups in haemoglobin (p = 0.03), haematocrit (p = 0.01), red blood cell levels (p = 0.03), leukocyte count (p < 0.001), neutrophil count (p < 0.001), lymphocyte count (p = 0.006), mean platelet volume (p = 0.04), and neutrophil/lymphocyte ratio (p = 0.03). In post hoc analysis, haemoglobin, haematocrit and RBC were significantly higher in group 1 than in group 3 (post hoc Tukey, p < 0.05). A statistically significant negative correlation was noted between 25(OH)D3 level and haemoglobin (r = -0.236), haemotocrit (r = -0.230), and red blood cell (r = -0.265) levels.

CONCLUSIONS

Vitamin D intoxication has been observed to affect haemoglobin, haematocrit, and RBC levels negatively. However, more studies are needed to clarify the effects and mechanisms of high vitamin D levels on the haematopoietic system.

Combinations of Calcitriol with Anticancer Treatments for Breast Cancer: An Update

Preclinical, clinical, and epidemiological studies indicate that vitamin D3 (VD) deficiency is a risk factor for the development of breast cancer. Underlying mechanisms include the ability of calcitriol to induce cell differentiation, inhibit oncogenes expression, and modify different signaling pathways involved in the control of cell proliferation. In addition, calcitriol combined with different kinds of antineoplastic drugs has been demonstrated to enhance their beneficial effects in an additive or synergistic fashion. However, a recognized adjuvant regimen based on calcitriol for treating patients with breast cancer has not yet been fully established. Accordingly, in the present work, we review and discuss the preclinical and clinical studies about the combination of calcitriol with different oncological drugs, aiming to emphasize its main therapeutic benefits and opportunities for the treatment of this pathology.

Narrative review of recent studies on the role of vitamin D in the prevention of cardiac and renal risk and additional considerations for COVID-19 vulnerability

The role of vitamin D in maintaining a healthy cardiovascular (CV) and the renal system has received increasing attention. Low vitamin D levels are associated with the incidence of hypertension, cardiac remodeling, and chronic congestive heart failure. Low vitamin D levels also influence renal disease progression and albuminuria deterioration. Moreover, recent research indicates that vitamin D deficiency can be a potential risk factor for coronavirus disease-19 (COVID-19) infection and poorer outcomes. Data are inconclusive as to whether supplementation with vitamin D agents reduces CV disease risk or COVID-19 severity. Conversely, in patients with kidney disease, vitamin D supplementation is associated with improved kidney function and albuminuria. This narrative review considers recent data on the effects of vitamin D on the CV and renal system, as well as its possible role regarding COVID-19 complications.

Vitamin D: Skin, sunshine, and beyond

Vitamin D is a steroid hormone of importance to the field of dermatology. Skin is unique in that it is the site of vitamin D synthesis upon sun exposure and a target organ for its activity. We explore the physiology and metabolic mechanism of action of vitamin D, as well as its effects on the skin. We also discuss the current evidence of the efficacy and safety of oral and topical vitamin D analogues on skin conditions such as psoriasis, atopic dermatitis, vitiligo, sunburn, actinic keratosis, and fibrosing skin disorders. Based on currently available scientific evidence, the National Academy of Medicine's recommended dietary allowance for vitamin D ranges from 400 IU to 800 IU daily based on age categories.

Renal involvement in sarcoidosis: histological patterns and prognosis, an Italian survey

Background

Granulomatous interstitial nephritis in sarcoidosis (sGIN) is generally clinically silent, but in <1% causes acute kidney injury (AKI).

Methods

This Italian multicentric retrospective study included 39 sarcoidosis-patients with renal involvement at renal biopsy: 31 sGIN-AKI, 5 with other patterns (No-sGIN-AKI), 3 with nephrotic proteinuria. We investigate the predictive value of clinical features, laboratory, radiological parameters and histological patterns regarding steroid response. Primary endpoint: incident chronic kidney disease (CKD) beyond the 1°follow-up (FU) year; secondary endpoint: response at 1°line steroid therapy; combined endpoint: the association of initial steroid response and outcome at the end of FU.

Results

Complete recovery in all 5 No-sGIN-AKI-patients, only in 45% (13/29) sGIN-AKI-patients (p=0.046) (one lost in follow-up, for another not available renal function after steroids). Nobody had not response. Primary endpoint of 22 sGIN-AKI subjects: 65% (13/20) starting with normal renal function developed CKD (2/22 had basal CKD; median FU 77 months, 15-300). Combined endpoint: 29% (6/21) had complete recovery and final normal renal function (one with renal relapse), 48% (10/21) had partial recovery and final CKD (3 with renal relapse, of whom one with basal CKD) (p=0.024). Acute onset and hypercalcaemia were associated to milder AKI and better recovery than subacute onset and patients without hypercalcaemia, women had better endpoints than men. Giant cells, severe interstitial infiltrate and interstitial fibrosis seemed negative predictors in terms of endpoints.

Conclusions

sGIN-AKI-patients with no complete recovery at 1°line steroid should be treated with other immunosuppressive to avoid CKD, in particular if males with subacute onset and III stage-not hypercalcaemic AKI.

Multiple osteolytic primary peripheral T-cell bone lymphoma: the first case report

Peripheral T-cell lymphoma accounts for about 10% of all cases of non-Hodgkin’s lymphoma. However, less than 5% of patients with non-Hodgkin’s lymphoma present with hypercalcaemia as the initial symptom, and less than 1% present with primary bone lesions. We herein describe a 76-year-old Chinese man who was diagnosed with primary bone adult T-cell lymphoma with extensive osteolysis, including bone loss in the radius, as the initial manifestation. He had developed severe generalised bone pain and an inability to raise his arms. X-ray examination revealed osteolytic destruction of the forearm with loss of the radial diaphysis. The patient was diagnosed with peripheral T-cell lymphoma based on his immunohistochemical results. He began treatment with the CHOPE chemotherapy regimen, which resulted in significant improvement of his bone pain.

Effect of vitamin D supplementation on OPG/RANKL signalling activities in endothelial tissue damage in diet-induced diabetic rat model

BACKGROUND

Type 2 Diabetes Mellitus is a chronic metabolic disease that causes endothelial damage and is an important risk factor for atherosclerosis. In the present study vitamin D3 supplementation in rats was used to determine the role of Osteoprotegerin (OPG)/Receptor activator kB ligand (RANKL) signalling in endothelial damage and changes in the expression levels of genes involved in this pathway. We hypothesized that vitamin D3 supplementation affects OPG and RANKL activity in the aorta.

METHODS

Diabetes was induced in rats via injections of 40 mg/kg of streptozotocin followed by a high fructose (10%) diet. Group 2 (healthy) and 4 (diabetic) received 170 IU/kg of vitamin D3 weekly for 5 weeks, while Group 1 (healthy) and 2 (diabetic) received sterile saline. The aortas of each group were collected to analyse mRNA expression using the real-time PCR method and also to evaluate magnesium and calcium levels using inductively coupled plasma mass spectrometry.

RESULTS

Opg and Il-1b expression levels were significantly associated with both diabetes and vitamin D3 supplementation in the aortas of the study groups (p ≤ 0.05). Opg mRNA expression was also found to correlate with both Icam-1 and Nos3 mRNA expression levels (r = 0.699, p = 0.001 and r = 0.622, p = 0.003, respectively). In addition, when mineral levels in the aortic tissues were compared among all groups, it was found that the interaction of diabetes and vitamin D3 supplementation significantly affected Mg levels and Mg/Ca ratios.

CONCLUSIONS

It is concluded that vitamin D3 supplementation has a modulatory effect on OPG/RANKL activity in the vessel wall by ameliorating endothelial damage in diabetes. This effect may contribute to the regulation of cytokine-mediated vascular homeostasis and mineral deposition in the aorta; therefore, further comprehensive studies are proposed to demonstrate this relationship.

Effects of Supplementation in Vitamin D3 Deficient or Insufficient Children with Allergic Diseases

Background and Objectives: Although vitamin D insufficiency or deficiency is prevalent in children with allergic diseases, recommendations for supplementation dosing regimens are imprecise and variable in the literature, because clinical trials aiming to determine optimal doses were scarce in the past. This study aimed to investigate supplementation of vitamin D3 that may achieve therapeutically effective but not toxic serum levels in a subpopulation of children with allergic diseases and concomitant hypovitaminosis D. Materials and Methods: The retrospective, observational study with a cross-sectional design included 94 children suffering from allergic diseases and having vitamin D deficiency/insufficiency who were prescribed high-dose vitamin D3 supplementation by a pediatrician for at least 6 weeks and not more than 9 weeks. Serum levels of the major metabolite of vitamin D (25-(OH)D) were determined in all children twice: before and two weeks after the end of vitamin D3 supplementation. Results: An increase in serum level of the 25-(OH)D after supplementation was significant. However, if the subjects had higher serum levels of the 25-(OH)D before the supplementation, and if the supplementation lasted 8 instead of 6 weeks, the absolute increase in serum level of the 25-(OH)D was lower. Patients taking corticosteroids as inhalation or intranasally had a more intense effect of vitamin D3 supplementation, i.e., the absolute increase in levels of 25-(OH)D was higher than in patients not using such medication. Conclusions: Vitamin D deficiency and insufficiency in children with allergic diseases can be treated with maximal recommended doses of vitamin D3 for a short period of time, especially if they were prescribed with inhalation or intranasal corticosteroids.

Vitamin D and Rheumatic Diseases: A Review of Clinical Evidence

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

Hypercalcemia Owing to Overproduction of 1,25-Dihydroxyvitamin D3 in Fetal Lung Adenocarcinoma: Case Report

Hypercalcemia is a common electrolyte abnormality in malignancy and is largely caused by activation of parathyroid hormone (PTH) pathways. We report the case of a 76-year-old man with hypercalcemia primarily owing to 1,25-dihydroxyvitamin D₃ overproduction from a high-grade fetal lung adenocarcinoma. Histologically, the tumor itself and tumor-adjacent macrophages were positive for the CYP27B1 protein, a key enzyme that generates 1,25-dihydroxyvitamin D₃. Suppression was observed in serum PTH and PTH-related hormone levels, suggesting hypercalcemia is independent of the PTH pathway. Serum calcium level returned to normal after surgical resection of the lung cancer, supporting extrarenal overproduction of 1,25-dihydroxyvitamin D₃ elicited by the tumors is the cause of hypercalcemia in this patient.

Huge cutaneous abscess and severe symptomatic hypercalcaemia secondary to Mycobacterium kansasii infection in an immunocompetent patient

Mycobacterium kansasii is among the most common non-tuberculous mycobacteria causing human infections. Apart from pulmonary infection, the most common infection caused by M. kansasii is skin and soft tissue infection, and it is very rare in immunocompetent people. In this report, we present a case of a huge cutaneous abscess caused by M. kansasii A 63-year-old man living in Bangkok presented with progressive pain at the left lateral chest wall for 3 weeks and altered mentation for a few days. Examination revealed a non-tender fluctuated cutaneous mass 20×10 cm in size. An aspiration of the mass yielded 50 mL pus with many positive acid-fast bacilli. Mycobacterial PCR was positive for M. kansasii with culture confirmation. There was severe hypercalcaemia. The treatment included surgical drainage, and medical treatment consisted of isoniazid, rifampicin, ethambutol and levofloxacin, along with adequate hydration and calcitonin for hypercalcaemia. The patient gradually improved and was discharged 12 days after hospitalisation.

Infantile hypercalcaemia type 1: a vitamin D-mediated, under-recognised cause of hypercalcaemia

SUMMARY

A 33-year-old gentleman of Egyptian heritage presented with a 21 years history of unexplained and recurrent hypercalcaemia, nephrolithiasis, nephrocalcinosis, and myocarditis. A similar history was also found in two first-degree relatives. Further investigation into the vitamin D metabolism pathway identified the biochemical hallmarks of infantile hypercalcaemia type 1 (IIH). A homozygous, likely pathogenic, variant in CYP24A1 was found on molecular genetic analysis confirming the diagnosis. Management now focuses on removing excess vitamin D from the metabolic pathway as well as reducing calcium intake to achieve serum-adjusted calcium to the middle of the reference range. If undiagnosed, IIH can cause serious renal complications and metabolic bone disease.

LEARNING POINTS

Infantile hypercalcaemia type 1 (IIH) is an autosomal recessive disorder characterised by homozygous mutations in the CYP24A1 gene that encodes the 24-hydroxylase enzyme used to convert active vitamin D metabolites such as 1,25-(OH)2-vitamin D into their inactive form. IIH should be questioned in individuals presenting with a history of unexplained hypercalcaemia, especially if presenting from childhood and/or where there is an accompanying family history of the same in first and/or second degree relatives, causing complications such as nephrocalcinosis, pericarditis, and calcium-based nephrolithiasis. Associated biochemistry of IIH is persistent mild to moderate hypercalcaemia, normal or raised 25-(OH)-vitamin D and elevated 1,25-(OH)2-vitamin D. An elevated ratio of 25-(OH)-vitamin D to 24,25-(OH)2-vitamin D can be a useful marker of defects in the 24-hydroxylase enzyme, whose measurement can be facilitated through the supra-regional assay service. Management should focus on limiting the amount of vitamin D introduced into the body either via sunlight exposure or supplementation in addition to calcium dietary restriction to try and maintain appropriate calcium homeostasis.

Disorders of Divalent Ions (Magnesium, Calcium, and Phosphorous) in Patients With Cancer

Disorders of the divalent ions (magnesium, calcium, and phosphorous) are frequently encountered in patients with cancer. Of these, hypomagnesemia, hypocalcemia, hypercalcemia, and hypophosphatemia are seen most commonly. These electrolyte disturbances may be related to the underlying malignancy or due to side effects of anticancer therapy. When caused by a paraneoplastic process, these abnormalities may portend a poor prognosis. Importantly, the development of severe electrolyte derangements may be associated with symptoms that negatively impact quality of life, preclude the administration of critical chemotherapeutic agents, or lead to life-threatening complications that require hospitalization and emergent treatment. In accordance, prompt recognition and treatment of these disorders is key to improving outcomes in patients living with cancer. This review will discuss selected derangements of the divalent ions seen in this population, with a focus on paraneoplastic and therapy-associated etiologies.

HLA-DRB1 alleles associate with hypercalcemia in sarcoidosis

BACKGROUND

The mechanisms behind and which patients are at risk of developing sarcoidosis associated hypercalcemia (SAHC) have not been addressed. Different human leukocyte antigen (HLA) alleles associate with disease phenotypes in sarcoidosis. Insights into associations between HLA alleles, clinical phenotype and calcium levels may provide clues to mechanisms behind SAHC and help monitoring patients at risk for SAHC.

AIMS AND OBJECTIVES

To identify any HLA-association with SAHC, and to phenotypically characterize this patient group.

METHODS

66 patients with SAHC (s-Ca²⁺>1.33 mmol/L) and 150 normocalcemic patients as controls were identified in a cohort of sarcoidosis patients. Data on HLA-DRB1 alleles, sex, angiotensin-converting enzyme (ACE), creatinine, extrapulmonary manifestations (EPM), age at sarcoidosis diagnosis, and how long after diagnosis SAHC emerged, were retrieved.

RESULTS

HLA-DRB1*04 was more common in patients with SAHC and the proportion of patients with HLA-DRB1*04 increased the more pronounced hypercalcemia. In patients with s-Ca²⁺>1.4 mmol/L, 20 out of 30 carried the HLA-DRB1*04 allele (67%, p < 0.01). Patients with SAHC more often disclosed renal insufficiency, elevated ACE, EPM, and a non-resolving disease than controls. The mean duration between sarcoidosis diagnosis and detection of SAHC was 1.39 years.

CONCLUSIONS

SAHC is associated with a more severe disease phenotype, particularly patients carrying the HLA-DRB1*04 allele are at higher risk for SAHC. HLA-assessment in the clinic can be a way to identify these patients. The results provide a basis for future studies on the connection between HLA-DRB1*04 and SAHC mechanisms.