Hypercalcemia due to hypervitaminosis D: report of seven patients

Analytical Unreliability of 25 Hydroxy Vitamin D Measurements in Pre-Term Neonates

BACKGROUND

Vitamin D supplementation is common practice for neonates and infants due to limited stores of vitamin D at birth. Although not commonly encountered, vitamin D toxicity can occur due to over-supplementation. However, toxic concentrations are often not included in method validation experiments, and assays often are not validated in the neonatal population.

METHODS

We compared serial 25 hydroxy vitamin D [25(OH)D] measurements in pre-term neonates receiving 25(OH)D supplementation and identified 12 patients wherein concentrations of 25(OH)D were above 50 ng/mL (125 nM) that required additional investigations as the 25(OH)D results did not match the clinical picture. Available samples were compared across 4 immunoassay platforms (LIAISON XL, Roche Cobas e602, Abbott Alinity i, and Siemens Centaur XP) and LC-MS/MS.

RESULTS

Concentrations of 25(OH)D observed on one individual immunoassay platform (LIAISON XL) fluctuated substantially between subsequent blood draws in select neonates with elevated concentrations. Serum samples from these patients showed variable agreement between LC-MS/MS and other immunoassay platforms. These fluctuations were not explained by the presence of 3-epimer-25(OH)D or 24,25(OH)2D.

CONCLUSIONS

Although we were unable to identify a cause for the variable elevated results, our findings suggest that neonatal 25(OH)D measurements alone should not be used for assessment of nutritional monitoring, and that clinical correlation and other laboratory parameters including ionized calcium should be considered.

Clinical Toxicology of Vitamin D in Pediatrics: A Review and Case Reports

Intoxication of vitamin D is not a common case in pediatrics. Vitamin D supplements are sold as OTC drugs; however, there is a lack of public education about the permissible limits of vitamin D intake which may lead to vitamin D toxicity (VDT). This review aims to give insights to readers or practitioners about the clinical toxicology of vitamin D in pediatrics, which includes the mechanism of VDT, case reports, and the management of vitamin D poisoning. VDT refers to serum 25(OH)D levels, particularly when the level exceeds 100 ng/mL (250 nmol/L) or is defined as hypervitaminosis D. Hypercalcemia is a common condition of vitamin D toxicity. Vitamin D and its metabolites in moderate levels can induce hypercalcemia, as indicated by the elevation of osteoclastic bone resorption, the presence of calcium in renal tubules, intestinal calcium intake (through increased production of calcium-binding protein in enterocytes), and the decrease of parathyroid hormone synthesis. VDT in pediatrics can be managed by discontinuing vitamin D intake; using activated charcoal, furosemide, prednisone, and calcitonin; rehydration using intravenous sodium chloride 0.9%; and dextrose fluid therapy. It is important for parents to be more careful when providing vitamin D to their children.

Vitamin D supplementation leading to hypervitaminosis D in a breastfed infant: A case report

Breast milk alone is a poor and inadequate source of vitamin D. Many guidelines suggest supplementation of vitamin D to the newborns to prevent vitamin D deficiency. However, due to practices of outdoor breastfeeding and sunbathing, vitamin D supplementation may not be routinely required in our settings. Overzealous use of vitamin D supplementation and over-the-counter prescription may result in hypervitaminosis D.

Vitamin D: sources, physiological role, biokinetics, deficiency, therapeutic use, toxicity, and overview of analytical methods for detection of vitamin D and its metabolites

Vitamin D has a well-known role in the calcium homeostasis associated with the maintenance of healthy bones. It increases the efficiency of the intestinal absorption of dietary calcium, reduces calcium losses in urine, and mobilizes calcium stored in the skeleton. However, vitamin D receptors are present ubiquitously in the human body and indeed, vitamin D has a plethora of non-calcemic functions. In contrast to most vitamins, sufficient vitamin D can be synthesized in human skin. However, its production can be markedly decreased due to factors such as clothing, sunscreens, intentional avoidance of the direct sunlight, or the high latitude of the residence. Indeed, more than one billion people worldwide are vitamin D deficient, and the deficiency is frequently undiagnosed. The chronic deficiency is not only associated with rickets/osteomalacia/osteoporosis but it is also linked to a higher risk of hypertension, type 1 diabetes, multiple sclerosis, or cancer. Supplementation of vitamin D may be hence beneficial, but the intake of vitamin D should be under the supervision of health professionals because overdosing leads to intoxication with severe health consequences. For monitoring vitamin D, several analytical methods are employed, and their advantages and disadvantages are discussed in detail in this review.

Nephrocalcinosis in children who received high-dose vitamin D

BACKGROUND

Vitamin D supplements are readily available as over-the-counter preparations. However, although rare, cases of vitamin D overdose still occur and are associated with nephrocalcinosis and life-threatening hypercalcemia. Errors in manufacturing of nutritional supplements may be a cause of vitamin D intoxication in children. This study aimed to identify factors associated with vitamin D overdose-related nephrocalcinosis in children due to manufacturing errors in supplements.

METHODS

This retrospective study reviewed medical charts of pediatric patients with non-registered supplement-related vitamin D overdose at a tertiary referral hospital between 2006 and 2011. Clinical and laboratory characteristics of patients with or without nephrocalcinosis were evaluated. Receiver operating characteristics curve and area under the receiver operating characteristics curve were used to determine the most predictive value of each characteristic.

RESULTS

A total of 44 patients (males: 29; age: 7-62 months) were included. Age ≤ 16.5 months, body weight ≤ 10.25 kg, body height ≤ 78.5 cm, body surface area (BSA) ≤ 0.475 m², 25-hydroxyvitamin D₃ ≥ 143 ng/mL, and calcium ≥ 10.65 mg/dL were predictive of developing nephrocalcinosis with a sensitivity and specificity of > 60%. Univariant analysis revealed that BSA was the most significant anthropometric prognostic factor (odds ratio: 12.09; 95% confidence interval: 2.61-55.72; P = 0.001).

CONCLUSIONS

Children with smaller BSAs were more vulnerable to high-dose vitamin D₃-related nephrocalcinosis. Physicians and parents should be aware of the potential adverse effects of vitamin D overdose in children. A higher resolution version of the Graphical abstract is available as Supplementary information.

Vitamin D intoxication and severe hypercalcaemia complicating nutritional supplements misuse

This case report discusses an uncommon presentation of vitamin D intoxication and severe hypercalcaemia attributed to misuse of multiple nutritional supplements (˃20 active agents). A review of this case, supported by accumulated literature, lends room to further public health safety discussions. The multisystemic clinical manifestations of vitamin D toxicity can be debilitating, hence the need to prevent its occurrence.

Vitamin D Toxicity

Fortification of food products with vitamin D was central to the eradication of rickets in the early parts of the 20th century in the United States. In the subsequent almost 100 years since, accumulating evidence has linked vitamin D deficiency to a variety of outcomes, and this has paralleled greater public interest and awareness of the health benefits of vitamin D. Supplements containing vitamin D are now widely available in both industrialized and developing countries, and many are in the form of unregulated formulations sold to the public with little guidance for safe administration. Together, this has contributed to a transition whereby a dramatic global increase in cases of vitamin D toxicity has been reported. Clinicians are now faced with the challenge of managing this condition that can present on a spectrum from asymptomatic to acute life-threatening complications. This article considers contemporary data on vitamin D toxicity, and diagnostic and management strategies relevant to clinical practice.

Vitamin D Intoxication Presenting as Subacute Encephalopathy-A Case Report

Vitamin D intoxication is uncommon in children and is more commonly suspected in the setting of ingestion of high doses of vitamin D. Its manifestations can be non specific and varied ranging from mild like constipation and vomiting to life threatening like arrhythmias and encephalopathy. Here we present a 14 month female who presented with loss of milestones, floppiness, and poor interaction with mother. She was detected to have hypercalcemia and was subsequently diagnosed with vitamin D intoxication. She was successfully treated with hydration, furosemide, prednisolone and frequent monitoring of electrolytes, electrocardiography and volume status. Subsequently as her serum calcium levels normalized with therapy, she became alert, conscious and started achieving developmental milestones.

Vitamin D intoxication due to misuse: 5-year experience

INTRODUCTION

Vitamin D intoxication (VDI) is a well-known cause of hypercalcemia in children and leads to serious kidney, heart, and neurological problems. In the treatment of VDI, the goal is to correct hypercalcemia. Our aim was to evaluate the clinical features of patients with VDI, identify the causes of VDI in our region, and help guide precautions and treatment of VDI.

MATERIALS AND METHODS

The medical records of patients with VDI presenting between January 2015 and December 2019 were retrospectively analyzed.

RESULTS

In total, 38 patients aged 0.3-4 years including 20 males (52.6%) were included in the study. Vomiting (65.8%), loss of appetite (47.4%), and constipation (31.6%) were the most common symptoms. The cause of intoxication was prescribed D₃ vials in 23 patients, non-prescribed D₃ vials in nine patients, and incorrectly produced fish oil supplement in six patients. Admission serum calcium and 25 (OH) D levels were 3.75±0.5mmol/L and 396±110ng/mL, respectively. A statistically significant correlation was found between the serum calcium levels at the time of diagnosis and the dose of vitamin D received, serum 25 (OH) D, phosphorus, and parathyroid (PTH) levels. Nephrocalcinosis was present in 15 (39.5%) patients. The mean time to achieve normocalcemia was 6.18±2 days. The mean time to achieve normocalcemia in patients treated with pamidronate was 5.94±0.7 days.

CONCLUSION

Stoss therapy should not be administered for children of families with problems of adherence to treatment. It should be noted that VDI may develop as a result of improperly produced nutritional supplements. General practitioners and pediatricians must be aware of VDI risks and explain them to parents. Pamidronate is effective for treating VDI in children.

Vitamin D deficiency and mortality among critically ill surgical patients in an urban Korean hospital

Critically ill patients in intensive care units (ICUs) are exposed to various risk factors for vitamin D deficiency. Vitamin D deficiency in extended-stay patients may result in decreased muscle mass and increased fat tissue, which may impair rehabilitation and recovery. Our study aimed to evaluate the degree of serum vitamin D deficiency in critically ill surgical patients and its association with clinical outcomes. Clinical data from 186 adult male (n = 121; 65.1%) and female (n = 65; 34.9%) patients hospitalized in surgical ICUs at Ajou University Hospital from April 2015 to September 2016 were retrospectively analyzed. All adult surgical patients between the age of 18 and 88 years were enrolled. The mean serum 25-hydroxyvitamin D (25[OH]D) level of all patients was 17.8 ng/mL. A total of 120 patients (64.5%) with serum 25(OH)D levels < 20 ng/mL were classified as the deficiency group. A prolonged hospital stay was observed among the deficiency group but was not statistically significant (p = 0.824). Serum 25(OH)D levels were significantly correlated with age but inversely correlated with Sequential Organ Failure Assessment (SOFA) score, selenium, triglyceride, and C-reactive protein levels. There was no significant difference in mortality rates between the group with a vitamin D injection and the group without a vitamin D injection (14.6% vs. 16.9%, p = 0.074). Vitamin D deficiency was common in surgical ICU patients; however, vitamin D levels were higher in older patients. In conclusion, vitamin D deficiency was inversely associated with the SOFA severity score (Correlation Coefficient -0.165, p = 0.024) but was not associated with the length of hospital or ICU stay and mortality.

Comparison of Treatment Regimens in Management of Severe Hypercalcemia Due to Vitamin D Intoxication in Children

OBJECTIVE

No large study has been conducted to date to compare the effectiveness of prednisolone, alendronate and pamidronate as first-line treatment in children with hypercalcemia due to vitamin D intoxication. The aim was to perform a multicenter, retrospective study assessing clinical characteristics and treatment results.

METHODS

A standard questionnaire was uploaded to an online national database system to collect data on children with hypercalcemia (serum calcium level >10.5 mg/dL) due to vitamin D intoxication [serum 25-hydroxyvitamin D (25(OH)D) level >150 ng/mL] who were treated in pediatric endocrinology clinics.

RESULTS

Seventy-four children [median (range) age 1.06 (0.65-1.60) years, 45 males (61%) from 11 centers] were included. High-dose vitamin D intake was evident in 77% of the cases. At diagnosis, serum calcium, phosphorus, alkaline phosphatase, 25(OH)D and parathyroid hormone concentrations were 15±3.2 mg/dL, 5.2±1.2 mg/dL, 268±132 IU/L, 322 (236-454) ng/mL, and 5.5 (3-10.5) pg/mL, respectively. Calcium levels showed moderate correlation with 25(OH)D levels (r_s=0.402, p<0.001). Patients were designated into five groups according to the initial specific treatment regimens (hydration-only, prednisolone, alendronate, pamidronate, and combination). Need for another type of specific drug treatment was higher in children who initially received prednisolone (p<0.001). Recurrence rate of hypercalcemia was significantly lower in children who were treated with pamidronate (p=0.02).

CONCLUSION

Prednisolone is less effective in the treatment of children with severe hypercalcaemia secondary to vitamin D intoxication and timely implementation of other treatment regimens should be considered.

Vitamin D Toxicity: A Prospective Study from a Tertiary Care Centre in Kashmir Valley

BACKGROUND

Vitamin D toxicity (VDT), a "not uncommon" cause of hypercalcemia, can be life-threatening and cause substantial morbidity, if not treated promptly.

AIMS

To describe presentation, management, and outcome in 32 patients with VDT diagnosed over 3 years.

MATERIALS AND METHODS

Patients presenting with VDT at a tertiary care centre in Srinagar Kashmir India were included. Evaluation included detailed history and biochemical tests including serum calcium, phosphate, creatinine, intact parathyroid hormone (iPTH), 25-hydroxy Vitamin D (25-OHD), and 24-hour urinary calcium.

RESULTS

The clinical manifestations of the 32 patients (median age 65; range 3-77 years) included gastrointestinal symptoms (constipation and vomiting), polyuria/polydipsia, altered sensorium, pancreatitis, acute kidney injury, and nephrocalcinosis. The median total serum calcium level was 13.95 (range 11.10-17.20) mg/dl and median 25-OHD level was 306 (range 105-2800) ng/ml. All patients had suppressed or low normal iPTH and hypercalciuria and 78% had azotemia. All patients had received multiple intramuscular injections of vitamin D₃. The median cumulative dose was 4,200,000 (range, 1,800,000-30,000,000) IU. The median time to resolution of hypercalcemia was 7 months (range 4-18 months).

CONCLUSION

We conclude that VDT is an increasingly common cause of symptomatic hypercalcemia. VDT needs prolonged follow up as it takes months to abate its toxicity. Enhancing awareness among general practitioners regarding the toxicity resulting from high doses of vitamin D is the key to prevent VDT. We suggest that VDT be considered in patients, especially the elderly, presenting with polyuria, polydispsia, vomiting, azotemia, or encephalopathy.

No Severe Hypercalcemia with Daily Vitamin D3 Supplementation of up to 30 µg during the First Year of Life

BACKGROUND

Vitamin D supplementation is widely recommended for infants, but the optimal dose remains unclear. High intake may result in hypercalcemia.

METHODS

We evaluated the incidence of hypercalcemia during the first year of life in a cohort of 987 healthy children who received 10 or 30 μg of vitamin D3 supplementation daily. Ionized calcium (Ca-ion) was analyzed at 6 and 12 months, and serum 25-hydroxyvitamin D (25-OHD) and parathyroid hormone (PTH) concentration at 12 months. Severe hypercalcemia was defined as Ca-ion exceeding the reference limit (1.16-1.39 mmol/L) by 10%.

RESULTS

No severe hypercalcemia occurred. Mild hypercalcemia (1.40-1.52 mmol/L) was present at 6 months in 28% and at 12 months in 2% of infants. At 12 months, 25-OHD ranged between 23 and 241 nmol/L (median 97), and PTH was between undetectable and 104 pg/mL (median 24) and was below the reference range (11.5-78.4 pg/mL) in 11%. 25-OHD and Ca-ion correlated positively (r = 0.149), and 25-OHD was slightly higher in the 12 infants with mild hypercalcemia (median 97 vs. 110 nmol/L, p = 0.046).

CONCLUSIONS

Vitamin D3 supplementation of 10 or 30 µg did not cause severe hypercalcemia. Mild hypercalcemia was more prevalent at 6 months than at 12 months, and was associated weakly with 25-OHD at 12 months.

A review of the growing risk of vitamin D toxicity from inappropriate practice

Vitamin D is a particularly important sterol hormone, with evidence emerging of its beneficial effects well beyond bone. In consequence of this and increased global recognition of vitamin D deficiency in the general population, there has been a resurgence in treatment with vitamin D preparations. However, the increasing use of vitamin D treatments has also seen a substantial increase in the number of reports of vitamin D intoxication, with the majority (75%) of reports published since 2010. Many of these cases are a consequence of inappropriate prescribing, and the use of high-dose over-the-counter preparations or unlicensed preparations. This review highlights that the majority of cases were preventable and discusses the inappropriate use of poorly formulated, and unlicensed vitamin D preparations.

The changing profile of hypercalcemia in a tertiary care setting in North India: an 18-month retrospective study

This retrospective study was undertaken to determine the profile of hypercalcemia in all patients who presented to Medanta-The Medicity, a tertiary care hospital in North India. A total of 255,830 patients presented to the hospital during 1^st January 2014 till 30^th June 2015 (18 months). Among them calcium measurement was done in 26,297 (10.2%) patients. A total of 552 patients was found to have hypercalcemia. Among them, 15 (2.7%) patients had transient hypercalcemia and 537 (97.3%) had sustained hypercalcemia. The incidence of hypercalcemia was 2.09%, being transient in 0.05% and sustained in 2.04%. The most common causes in the sustained group were malignancy (23.1%) followed by primary hyperparathyroidism (PHPT, 21.9%). Most cases of PHPT were asymptomatic. Interestingly, we found emergence of two unusual groups of hypercalcemia, namely hypercalcemia of advanced chronic liver disease (n = 34) and vitamin D toxicosis (n = 21) in the non-parathyroid group of hypercalcemia. This changing pattern of hypercalcemia should be kept in mind while evaluating a patient of hypercalcemia in a hospital setting.

Clinical practice recommendations for native vitamin D therapy in children with chronic kidney disease Stages 2-5 and on dialysis

Vitamin D deficiency is widely prevalent and often severe in children and adults with chronic kidney disease (CKD). Although native vitamin D {25-hydroxyvitamin D [25(OH)D]} is thought to have pleiotropic effects on many organ systems, its skeletal effects have been most widely studied. The 25(OH)D deficiency is causally linked with rickets and fractures in healthy children and those with CKD, contributing to the CKD-mineral and bone disorder (MBD) complex. There are few studies to provide evidence for vitamin D therapy or guidelines for its use in CKD. A core working group (WG) of the European Society for Paediatric Nephrology (ESPN) CKD-MBD and Dialysis WGs have developed recommendations for the evaluation, treatment and prevention of vitamin D deficiency in children with CKD. We present clinical practice recommendations for the use of ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3) in children with CKD Stages 2-5 and on dialysis. A parallel document addresses treatment recommendations for active vitamin D analogue therapy. The WG has performed an extensive literature review to include meta-analyses and randomized controlled trials in healthy children as well as children and adults with CKD, and prospective observational studies in children with CKD. The Grading of Recommendation, Assessment, Development and Evaluation (GRADE) system has been used to develop and grade the recommendations. In the absence of applicable study data, the opinion of experts from the ESPN CKD-MBD and Dialysis WGs is provided, but clearly GRADE-ed as such and must be carefully considered by the treating physician, and adapted to individual patient needs as appropriate.

Vitamin D: Daily vs. Monthly Use in Children and Elderly-What Is Going On?

Vitamin D deficiency is highly prevalent among children and adults worldwide. Agreement exists that vitamin D deficiency should be corrected. However, the definitions of vitamin deficiency and effective vitamin D replacement therapy are inconsistent in the literature. Not only is the dosing regimen still under debate, but also the time and period of administration (i.e., daily vs. monthly dose). In pediatric as well as elderly subjects, dosing regimens with high vitamin D doses at less frequent intervals were proposed to help increase compliance to treatment: these became widespread in clinical practice, despite mounting evidence that such therapies are not only ineffective but potentially harmful, particularly in elderly subjects. Moreover, in the elderly, high doses of vitamin D seem to increase the risk of functional decline and are associated with a higher risk of falls and fractures. Achieving good adherence to recommended prophylactic regimens is definitely one of the obstacles currently being faced in view of the wide segment of the population liable to the treatment and the very long duration of prophylaxis. The daily intake for extended periods is in fact one of the frequent causes of therapeutic drop-outs, while monthly doses of vitamin D may effectively and safely improve patient compliance to the therapy. The aim of our paper is a quasi-literature review on dosing regimens among children and elderly. These two populations showed a particularly significant beneficial effect on bone metabolism, and there could be different outcomes with different dosing regimens.

Short-term UVB irradiation significantly increases vitamin D serum concentration in obese patients: a clinical pilot study

PURPOSE

Deficiency of vitamin D is very common in obese people and treatment by oral supplementation is not effective in all patients. This exploratory pilot study investigated the influence of different doses of short-term ultraviolet B irradiation on serum 25-hydroxyvitamin-D₃ (25D) and 1,25-dihydroxyvitamin-D₃ (1,25D) levels in obese compared to normal weight subjects and obese controls.

METHODS

Participants with skin types II and III (Fitzpatrick skin classification) were assigned to six groups including four intervention groups receiving irradiation (three groups of obese and one group of normal weight subjects) and two control groups without treatment (obese and normal weight). Intervention groups received three sessions of whole body UVB irradiation of three different doses (cumulative doses over three sessions: 0.28, 0.70, 1.75 minimal erythema dose) within 1 week of intervention. Serum 25D and 1,25D were measured at baseline and after irradiation. Outcome differences between groups were analyzed using a linear model.

RESULTS

Serum 25D levels increased significantly in obese (+23.6 and +26.7%, respectively, p = 0.01) and normal weight (+15.6%, p = 0.02) intervention groups who received medium and high doses of ultraviolet B irradiation compared to control groups (+3.5 and -4.0%, respectively, p = 1.0). The increase in obese patients was 51.4% greater compared to normal weight controls irradiated with equal ultraviolet B doses. Low-level ultraviolet irradiation did not result in a significant change in serum 25D (+7.0%, p = 0.61). We did not detect any significant differences of 1,25D between groups (p = 0.25).

CONCLUSIONS

The current study indicates that short-term ultraviolet B irradiation increases 25D levels in obese patients.

Serum vitamin D levels in Indian patients with retinal venous occlusions

Purpose

To estimate serum vitamin D (25 OH D) level in patients of retinal vein occlusion (RVO) and compare it with age-matched controls.

Methods and material

Forty patients above 18 years of age with retinal vein occlusion and forty age-matched controls underwent serum vitamin D (Vit D) level estimation using a standard protocol. Student’s t test was used to analyse differences between the mean of two groups.

Results

The mean age in RVO and control group was 60.25 and 60.73 years respectively. The mean (±SD) level of vitamin D in RVO patients was 13.68 (±4.58) ng/mL (range 5.5–24.8), and the 95% CI of mean was 12.21–15.14 with SD 4.58 while in control group it was 23.03 (±2.89) ng/ml (range 18.4–30.1) with 95% CI of mean being 22.11–23.96 with SD 2.89 (p value of <0.005). While comparing the level of Vitamin D based on type of occlusion the mean level of Vit D in CRVO patients was 15.36 (SD 5.30) and in BRVO it was 12.77 (SD 3.96) which was statistically not significant (p = 0.08). The odds ratio calculated for RVO cases versus controls was 133.33 which was statistically significant (P < 0.05).

Conclusions

There is a paucity of published literature on level of Vit D in RVO. This study shows significantly lower levels of serum vitamin D in Indian patients with retinal vein occlusion as compared to age matched controls. Establishment of this correlation has possible implications for prophylaxis or treatment of RVOs.

Comparison of 300,000 and 600,000 IU Oral Vitamin-D Bolus for Vitamin-D Deficiency in Young Children

OBJECTIVE

To compare the efficacy and safety of 300,000 and 600,000 IU vitamin-D single-oral dose for the treatment of vitamin-D deficiency (VDD) in young children (3 mo - 3 y).

METHODS

This double-blind randomized control trial (Clinical Trail Registration-CTRI/2012/05/002621) was conducted in the Pediatric out-patient department (OPD) at a tertiary-care referral hospital. Children (3 mo - 3 y) with clinical/radiological features suggestive of VDD were screened; those found to be having 25(OH)D below 15 ng/ml and meeting inclusion and exclusion criteria's were enrolled after taking informed consent. They were randomized into two groups, one receiving 600,000 and other 300,000 IU vitamin-D orally stat (Stoss-therapy). Primary outcome measure was proportion of children developing hypercalcemia/and hypercalciuria at day 7-10 post-therapy. Secondary outcome measures were proportion of children with hypercalciuria at day 3-5, hypercalcemia/and hypercalciuria at day 25-30 and 25(OH)D sufficiency at day 25-30 post-therapy.

RESULTS

Sixty children, 30 in each group were randomized to two study groups. Baseline variables were comparable in two groups. Primary outcome measure (proportion of children with hypercalcemia/and hypercalciuria at 7 - 10th d) were 18.5 % (5/27) in 600,000 and 10.7 % (3/28) in 300,000 IU group (P = 0.47). Secondary outcome measures were - i) Proportion of children with hypercalciuria (3-5th d) were 18.5 % (5/27) in 600,000 and 7 % (2/28) in 300,000 group (P = 0.25). ii) Proportion of children with hypercalcemia/and hypercalciuria (25-30th d) were 18.5 % (5/27) in 600,000 and 11 % (3/28) in 300,000 group (P = 0.47). iii) All children in both groups had 25(OH)D levels in sufficiency range (25-30th d). With this sample size no significant difference in any of the group could be established.

CONCLUSIONS

The superiority of 300,000 over 600,000 IU vitamin-D single-dose oral therapy for VDD in children (3 mo - 3 y) in terms of safety could not be established with this sample size, although the prevalence of hypercalcemia/and hypercalciuria was observed more with 600,000 IU group. Both the regimens were effective for treating VDD at 25-30th d post-therapy.

Global Consensus Recommendations on Prevention and Management of Nutritional Rickets

BACKGROUND

Vitamin D and calcium deficiencies are common worldwide, causing nutritional rickets and osteomalacia, which have a major impact on health, growth, and development of infants, children, and adolescents; the consequences can be lethal or can last into adulthood. The goals of this evidence-based consensus document are to provide health care professionals with guidance for prevention, diagnosis, and management of nutritional rickets and to provide policy makers with a framework to work toward its eradication.

EVIDENCE

A systematic literature search examining the definition, diagnosis, treatment, and prevention of nutritional rickets in children was conducted. Evidence-based recommendations were developed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system that describes the strength of the recommendation and the quality of supporting evidence.

PROCESS

Thirty-three nominated experts in pediatric endocrinology, pediatrics, nutrition, epidemiology, public health, and health economics evaluated the evidence on specific questions within five working groups. The consensus group, representing 11 international scientific organizations, participated in a multiday conference in May 2014 to reach a global evidence-based consensus.

RESULTS

This consensus document defines nutritional rickets and its diagnostic criteria and describes the clinical management of rickets and osteomalacia. Risk factors, particularly in mothers and infants, are ranked, and specific prevention recommendations including food fortification and supplementation are offered for both the clinical and public health contexts.

CONCLUSION

Rickets, osteomalacia, and vitamin D and calcium deficiencies are preventable global public health problems in infants, children, and adolescents. Implementation of international rickets prevention programs, including supplementation and food fortification, is urgently required.

Vitamin D Deficiency in Pediatric Critical Care

Vitamin D deficiency (VDD) is a well-established cause of pediatric bone and muscle disease. In addition, a role has been recognized for vitamin D in the health and stress response of other organs, including the cardiovascular, immune, and respiratory systems. As these organs are central to the development of and recovery from critical illness, VDD has been hypothesized to be a modifiable risk factor for ICU outcome. Over the past 5 years, a growing number of adult and pediatric critical care studies have investigated the prevalence of VDD and its association with illness severity and outcome. The adult studies have recently been synthesized in systematic reviews, with results that convincingly suggest the need for trials to determine whether optimization of vitamin D status improves outcome. In contrast, the pediatric ICU and related literature has not been similarly synthesized. The goal of this review is to describe vitamin D metabolism, known biological mechanisms, potential role in pathophysiology, and summarize the available pediatric intensive care unit (PICU) studies reporting on prevalence of VDD deficiency and its association with outcome. The problems with currently approved supplementation approaches and alternative strategies are discussed, including evidence from available RCTs in adult ICU. Altogether the results suggest that critically ill children are at risk for VDD, and that VDD appears to be associated with a worse clinical course. Clinical trials evaluating novel approaches to testing for and supplementing vitamin D require exploration.

Prevalence of hypercalcemia related to hypervitaminosis D in clinical practice

BACKGROUND & AIMS

Recent interest in vitamin D has led to a substantial increase in the use of vitamin D supplements. Vitamin D intoxication may be a concern as hypervitaminosis D can result in irreversible calcification of soft tissues so that it is important to detect early markers of vitamin D intoxication. Our aim was to assess the simultaneous presence of biochemical markers of vitamin D toxicity (i.e. hypervitaminosis D, hypercalcemia) and determine the concentrations of 25-OH-vitamin D at which the risk of hypercalcemia, and thus toxicity, might begin.

METHODS

We evaluated retrospectively a 6-year period during which 25.567 samples were assessed for 25-OH-vitamin D status by UHPLC. Hypervitaminosis D was defined at serum 25-OH-vitamin D >160 nmol/L. Serum and urine calcium, phosphorus and iPTH were also recorded, if available. Medical history revision was performed in subjects displaying simultaneously hypervitaminosis D and hypercalcemia.

RESULTS

Overall, hypervitaminosis D was found in 475 samples (1.86%) of which 51 displayed hypercalcemia (11.1%). A total of 382 samples were identified as the first record of hypervitaminosis D and 39 presented hypercalcemia (10.2%), most of them at 25-OH-vitamin D levels between 161 and 375 nmol/L. Only in 15 subjects, hypercalcemia could be directly attributed to vitamin D and serum 25-OH-vitamin D ranged between 164 and 1139 nmol/l. In no case, serum calcium achieved concentrations considered as critical values (>13 mg/dl).

CONCLUSION

Hypercalcemia due to vitamin D represented <4% of the total hypervitaminosis D detected and <0.1% of the tests performed. However, a highly variable response was observed and most subjects presented hypercalcemia at serum concentrations of 25-OH-vitamin D < 375 nmol/L.

Global Consensus Recommendations on Prevention and Management of Nutritional Rickets

BACKGROUND

Vitamin D and calcium deficiencies are common worldwide, causing nutritional rickets and osteomalacia, which have a major impact on health, growth, and development of infants, children, and adolescents; the consequences can be lethal or can last into adulthood. The goals of this evidence-based consensus document are to provide health care professionals with guidance for prevention, diagnosis, and management of nutritional rickets and to provide policy makers with a framework to work toward its eradication.

EVIDENCE

A systematic literature search examining the definition, diagnosis, treatment, and prevention of nutritional rickets in children was conducted. Evidence-based recommendations were developed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system that describe the strength of the recommendation and the quality of supporting evidence.

PROCESS

Thirty-three nominated experts in pediatric endocrinology, pediatrics, nutrition, epidemiology, public health, and health economics evaluated the evidence on specific questions within five working groups. The consensus group, representing 11 international scientific organizations, participated in a multiday conference in May 2014 to reach a global evidence-based consensus.

RESULTS

This consensus document defines nutritional rickets and its diagnostic criteria and describes the clinical management of rickets and osteomalacia. Risk factors, particularly in mothers and infants, are ranked, and specific prevention recommendations including food fortification and supplementation are offered for both the clinical and public health contexts.

CONCLUSION

Rickets, osteomalacia, and vitamin D and calcium deficiencies are preventable global public health problems in infants, children, and adolescents. Implementation of international rickets prevention programs, including supplementation and food fortification, is urgently required.

Vitamin D toxicity resulting from overzealous correction of vitamin D deficiency

BACKGROUND

Vitamin D toxicity, often considered rare, can be life-threatening and associated with substantial morbidity, if not identified promptly.

OBJECTIVE

To describe clinical and biochemical features, risk factors and management of patients with vitamin D toxicity seen between January 2011 and January 2013.

METHODOLOGY

Patients presenting with vitamin D toxicity, between January 2011 and January 2013, at single tertiary care centre in Delhi-NCR, India, were included. Evaluation included detailed clinical history and biochemical tests including serum calcium, phosphorus, creatinine, intact parathyroid hormone and 25-hydroxyvitamin D (25(OH)D).

RESULTS

Sixteen patients with vitamin D toxicity could be identified. Clinical manifestations included nausea, vomiting, altered sensorium, constipation, pancreatitis, acute kidney injury and weight loss. Median (range) age was 64·5 (42-86) years. Median (range) serum 25(OH)D level and median (range) serum total serum calcium level were 371 (175-1161) ng/ml and 13·0 (11·1-15·7) mg/dl, respectively. Overdose of vitamin D caused by prescription of mega-doses of vitamin D was the cause of vitamin D toxicity in all cases. Median (range) cumulative vitamin D dose was 3,600,000 (2,220,000-6,360,000) IU.

CONCLUSION

Our data demonstrate an emergence of vitamin D toxicity as an increasingly common cause of symptomatic hypercalcaemia. Irrational use of vitamin D in mega-doses resulted in vitamin D toxicity in all cases. Awareness among healthcare providers regarding the toxic potential of high doses of vitamin D and cautious use of vitamin D supplements is the key to prevent this condition.

Vitamin D and fetal-neonatal calcium homeostasis: findings from a randomized controlled trial of high-dose antenatal vitamin D supplementation

BACKGROUND

There is current interest in the maternal-fetal effects of antenatal vitamin D supplementation, yet little data regarding vitamin D's role in neonatal calcium homeostasis. We determined to assess the effect of high-dose antenatal vitamin D supplementation on fetal and neonatal calcium concentrations.

METHODS

In a double-blinded, placebo-controlled trial in Bangladesh, 160 pregnant women were randomized to oral vitamin D3 (35,000 IU/wk) or placebo from 26 to 29 wk of gestation.

RESULTS

Total serum calcium (Ca) was higher in cord blood of those supplemented vs. placebo (2.66 ± 0.1 vs. 2.61 ± 0.2 mmol/l; P = 0.04), but the difference in albumin-adjusted calcium was not statistically significant. Change in Ca concentration from birth to day 3 of life was attenuated by vitamin D (-0.10 ± 0.17) compared with placebo (-0.22 ± 0.18 mmol/l; P = 0.02). Maternal 25-hydroxyvitamin D (25(OH)D) (P = 0.04) and cord 25(OH)D (P < 0.01) were associated with day 3 infant Ca, suggesting that the effect of supplementation was mediated by change in maternal-infant vitamin D status. Six infants in each of the supplemented and placebo groups had transient hypercalcemia/hypercalcuria; in all the hypercalcemia/hypercalcuria was asymptomatic, spontaneously resolved, and unassociated with nephrocalcinosis at 1 mo of life.

CONCLUSION

High-dose antenatal third-trimester vitamin D supplementation attenuated the early postnatal calcium nadir, without increasing the risk of postnatal hypercalcemia.

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.

1,25(OH)₂D₃-enhanced hypercalciuria in genetic hypercalciuric stone-forming rats fed a low-calcium diet

The inbred genetic hypercalciuric stone-forming (GHS) rats exhibit many features of human idiopathic hypercalciuria and have elevated levels of vitamin D receptors (VDR) in calcium (Ca)-transporting organs. On a normal-Ca diet, 1,25(OH)2D3 (1,25D) increases urine (U) Ca to a greater extent in GHS than in controls [Sprague-Dawley (SD)]. The additional UCa may result from an increase in intestinal Ca absorption and/or bone resorption. To determine the source, we asked whether 1,25D would increase UCa in GHS fed a low-Ca (0.02%) diet (LCD). With 1,25D, UCa in SD increased from 1.2 ± 0.1 to 9.3 ± 0.9 mg/day and increased more in GHS from 4.7 ± 0.3 to 21.5 ± 0.9 mg/day (P < 0.001). In GHS rats on LCD with or without 1,25D, UCa far exceeded daily Ca intake (2.6 mg/day). While the greater excess in UCa in GHS rats must be derived from bone mineral, there may also be a 1,25D-mediated decrease in renal tubular Ca reabsorption. RNA expression of the components of renal Ca transport indicated that 1,25D administration results in a suppression of klotho, an activator of the renal Ca reabsorption channel TRPV5, in both SD and GHS rats. This fall in klotho would decrease tubular reabsorption of the 1,25D-induced bone Ca release. Thus, the greater increase in UCa with 1,25D in GHS fed LCD strongly suggests that the additional UCa results from an increase in bone resorption, likely due to the increased number of VDR in the GHS rat bone cells, with a possible component of decreased renal tubular calcium reabsorption.

Pharmacokinetics of high-dose weekly oral vitamin D3 supplementation during the third trimester of pregnancy in Dhaka, Bangladesh

A pharmacokinetic study was conducted to assess the biochemical dose-response and tolerability of high-dose prenatal vitamin D3 supplementation in Dhaka, Bangladesh (23°N). Pregnant women at 27–30 weeks gestation (n = 28) were randomized to 70,000 IU once + 35,000 IU/week vitamin D3 (group PH: pregnant, higher dose) or 14,000 IU/week vitamin D3 (PL: pregnant, lower dose) until delivery. A group of non-pregnant women (n = 16) was similarly administered 70,000 IU once + 35,000 IU/week for 10 weeks (NH: non-pregnant, higher-dose). Rise (∆) in serum 25-hydroxyvitamin D concentration ([25(OH)D]) above baseline was the primary pharmacokinetic outcome. Baseline mean [25(OH)D] were similar in PH and PL (35 nmol/L vs. 31 nmol/L, p = 0.34). A dose-response effect was observed: ∆[25(OH)D] at modeled steady-state was 19 nmol/L (95% CI, 1 to 37) higher in PH vs. PL (p = 0.044). ∆[25(OH)D] at modeled steady-state was lower in PH versus NH but the difference was not significant (−15 nmol/L, 95% CI −34 to 5; p = 0.13). In PH, 100% attained [25(OH)D] ≥ 50 nmol/L and 90% attained [25(OH)D] ≥ 80 nmol/L; in PL, 89% attained [25(OH)D] ≥ 50 nmol/L but 56% attained [25(OH)D] ≥ 80 nmol/L. Cord [25(OH)D] (n = 23) was slightly higher in PH versus PL (117 nmol/L vs. 98 nmol/L; p = 0.07). Vitamin D3 was well tolerated; there were no supplement-related serious adverse clinical events or hypercalcemia. In summary, a regimen of an initial dose of 70,000 IU and 35,000 IU/week vitamin D3 in the third trimester of pregnancy was non-hypercalcemic and attained [25(OH)D] ≥ 80 nmol/L in virtually all mothers and newborns. Further research is required to establish the safety of high-dose vitamin D3 in pregnancy and to determine if supplement-induced [25(OH)D] elevations lead to maternal-infant health benefits.

Increased biological response to 1,25(OH)(2)D(3) in genetic hypercalciuric stone-forming rats

Genetic hypercalciuric stone-forming (GHS) rats, bred to maximize urine (U) calcium (Ca) excretion, have increased intestinal Ca absorption and bone Ca resorption and reduced renal Ca reabsorption, leading to increased UCa compared with the Sprague-Dawley (SD) rats. GHS rats have increased vitamin D receptors (VDR) at each of these sites, with normal levels of 1,25(OH)(2)D(3) (1,25D), indicating that their VDR is undersaturated with 1,25D. We tested the hypothesis that 1,25D would induce a greater increase in UCa in GHS rats by feeding both strains ample Ca and injecting 1,25D (25 ng · 100 g body wt(-1) · day(-1)) or vehicle for 16 days. With 1,25D, UCa in SD increased from 1.7 ± 0.3 mg/day to 24.4 ± 1.2 (Δ = 22.4 ± 1.5) and increased more in GHS from 10.5 ± 0.7 to 41.9 ± 0.7 (Δ = 29.8 ± 1.8; P = 0.003). To determine the mechanism of the greater increase in UCa in GHS rats, we measured kidney RNA expression of components of renal Ca transport. Expression of transient receptor potential vanilloid (TRPV)5 and calbindin D(28K) were increased similarly in SD + 1,25D and GHS + 1,25D. The Na(+)/Ca(2+) exchanger (NCX1) was increased in GHS + 1,25D. Klotho was decreased in SD + 1,25D and GHS + 1,25D. TRPV6 was increased in SD + 1,25D and increased further in GHS + 1,25D. Claudin 14, 16, and 19, Na/K/2Cl transporter (NKCC2), and secretory K channel (ROMK) did not differ between SD + 1,25D and GHS + 1,25D. Increased UCa with 1,25D in GHS exceeded that of SD, indicating that the increased VDR in GHS induces a greater biological response. This increase in UCa, which must come from the intestine and/or bone, must exceed any effect of 1,25D on TRPV6 or NCX1-mediated renal Ca reabsorption.

Serum levels of 3-epi-25-OH-D3 during hypervitaminosis D in clinical practice

CONTEXT

Intoxication from vitamin D supplements has been rarely reported, but nowadays, it occurs more frequently. The presence of the C-3 epimer of 25-hydroxyvitamin D(3) (3-epi-25-OH-D(3)) is highly prevalent in adults, although there is little information regarding its in vivo relevance, if any, especially under pathological conditions.

OBJECTIVE

Our aim was to assess the presence of the 3-epi-25-OH-D(3) in serum samples displaying 25-OH-D(3) concentrations indicative of hypervitaminosis D.

DESIGN, SETTING, PATIENTS, AND MAIN OUTCOME MEASURE

A total of 58 samples displaying a wide range of concentrations of 25-OH-D(3) (>64-439 ng/ml) by ultrafast liquid chromatography were consecutively recruited and reassessed for the presence of 3-epi-25-OH-D(3) using a second chromatographic system. Data from additional biochemical tests performed as part of the patient evaluation were also recorded.

RESULTS

Mean relative contribution of 3-epi-25-OH-D(3) was less than 4%, and concentrations ranged from 2-28.6 ng/ml. Serum levels of the C3 epimer, but not the relative contribution, correlate with serum 25-OH-D(3). Overall, in subjects with 25-OH-D(3) concentrations indicative of hypervitaminosis D, the presence of the C-3 epimer and its levels were apparently unrelated to age, serum markers of renal and liver function, acute-phase reactants, and the presence of hypercalcemia. 3-Epi-25-OH-D(3) did not correlate with PTH, but subjects displaying PTH suppression (<14 pg/ml) showed higher concentrations of 3-epi-25-OH-D(3).

CONCLUSION

The relative contribution of 3-epi-25-D(3) was not significantly altered during hypervitaminosis D, although the absolute levels reached in serum may be biologically relevant. From a clinical viewpoint, although the small size of the group may affect the lack of relationships, the presence of 3-epi-25-OH-D(3) was apparently unrelated to serum markers of renal and liver function, acute-phase reactants, PTH, and the presence of hypercalcemia.

Hypercalcemia in children receiving pharmacologic doses of vitamin D

Vitamin D deficiency causes rickets, requiring vitamin D at doses greater than daily dietary intake. Several treatment regimens are found in the literature, with wide dosing ranges, inconsistent monitoring schedules, and lack of age-specific guidelines. We describe 3 children, ages 2 weeks to 2 and 9/12 years, who recently presented to our institution with hypercalcemia and hypervitaminosis D (25-hydroxyvitamin D levels >75 ng/mL), associated with treatment of documented or suspected vitamin D-deficient rickets. The doses of vitamin D used were within accepted guidelines and believed to be safe. The patients required between 6 weeks and 6 months to correct the elevated serum calcium, with time to resolution of hypercalcemia related to age and peak serum calcium, but not to peak 25-hydroxyvitamin D level. With recent widespread use of vitamin D in larger dosages in the general population, we provide evidence that care must be taken when using pharmacologic dosing in small children. With limited dosing guidelines available on a per weight basis, the administration of dosages to infants that are often used in older children and adults has toxic potential, requiring a cautious approach in dose selection and careful follow-up. Dosage recommendations may need to be reassessed, in particular, where follow-up and monitoring may be compromised.

Comparison of oral alendronate versus prednisolone in treatment of infants with vitamin D intoxication

AIM

The aim of this report was to compare the efficacy of oral alendronate versus prednisolone treatment in addition to conventional measures in infants with vitamin D intoxication.

METHODS

In six infants (aged 8.0 ± 2.1 months) with vitamin D intoxication, time to achieve normocalcemia with prednisolone treatment (Group I, n = 4) or alendronate treatment (Group II, n = 4, two infants started treatment from the baseline and two after unsuccessful prednisolone treatment) in addition to intravenous hydration and diuretic therapy were compared.

RESULTS

Baseline serum calcium levels ranged between 3.8 and 4.77 mmol/L. In the prednisolone group, although two patients reached normocalcemia on 7th and 12th days of treatment, other two patients did not despite 23 and 15 days of treatment and therefore switched to alendronate treatment. The mean duration of prednisolone treatment in these four patients was 14.2 ± 6.7 days (range 7-23). In the alendronate group, two patients who started treatment from the baseline achieved normocalcemia on the 5th day. Other two patients achieved normocalcemia 2 days after switching to alendronate. Thus, the mean time to reach normocalcemia after single oral alendronate administration was 3.5 ± 1.7 days (range 2-5) (p < 0.01 versus Group I).

CONCLUSION

Alendronate treatment achieves normocalcemia four times earlier than prednisolone treatment and shortens hospital stay in infants with vitamin D intoxication.

Vitamin d toxicity in adults: a case series from an area with endemic hypovitaminosis d

Vitamin D deficiency state is endemic to the Kashmir valley of the Indian subcontinent. Physicians often treat patients with high doses of vitamin D for various ailments and on occasion the prescribed doses far exceed the requirements of the patients. Ten cases of hypercalcemia due to vitamin D intoxication are presented with features of vomiting, polyuria, polydipsia, encephalopathy and renal dysfunction. All the patients had demonstrable hypercalcemia and vitamin D levels were high in nine of the 10 cases. The patients had received high doses of vitamin D and no other cause of hypercalcemia was identified. Treatment of hypercalcemia resulted in clinical recovery in nine cases. We conclude that hypervitaminosis D must be considered in the differential diagnosis of patients with hypercalcemia in endemically vitamin D deficient areas. A careful history and appropriate biochemical investigation will unravel the diagnosis in most of the cases.