Cardiac, bone and growth plate manifestations in hypocalcemic infants: revealing the hidden body of the vitamin D deficiency iceberg

Serum 25-hydroxyvitamin D threshold and risk of rickets in young children: a systematic review and individual participant data meta-analysis to inform the development of dietary requirements for vitamin D

PURPOSE

The objective of this systematic review was to determine a minimum serum 25-hydroxyvitamin D (25OHD) threshold based on the risk of having rickets in young children. This work was commissioned by the WHO and FAO within the framework of the update of the vitamin D requirements for children 0-3 years old.

METHODS

A systematic search of Embase was conducted to identify studies involving children below  4 years of age with serum 25OHD levels and radiologically confirmed rickets, without any restriction related to the geographical location or language. Study-level and individual participant data (IPD)-level random effects multi-level meta-analyses were conducted. The odds, sensitivity and specificity for rickets at different serum 25OHD thresholds were calculated for all children as well as for children with adequate calcium intakes only.

RESULTS

A total of 120 studies with 5412 participants were included. At the study-level, children with rickets had a mean serum 25OHD of 23 nmol/L (95% CI 19-27). At the IPD level, children with rickets had a median and mean serum 25OHD of 23 and 29 nmol/L, respectively. More than half (55%) of the children with rickets had serum 25OHD below 25 nmol/L, 62% below 30 nmol/L, and 79% below 40 nmol/L. Analysis of odds, sensitivities and specificities for nutritional rickets at different serum 25OHD thresholds suggested a minimal risk threshold of around 28 nmol/L for children with adequate calcium intakes and 40 nmol/L for children with low calcium intakes.

CONCLUSION

This systematic review and IPD meta-analysis suggests that from a public health perspective and to inform the development of dietary requirements for vitamin D, a minimum serum 25OHD threshold of around 28 nmol/L and above would represent a low risk of nutritional rickets for the majority of children with an adequate calcium intake.

Analysis of vitamin D3-sulfate and 25-hydroxyvitamin D3-sulfate in breastmilk by LC-MS/MS

Sulfated metabolites of vitamin D have been suggested to be in breastmilk, although current methods to measure sulfated vitamin D compounds in breastmilk by liquid chromatography-tandem mass spectrometry (LC-MS/MS) have not adequately accounted for increased aqueous solubility of these sulfated metabolites. The purpose of this study was to generate a method of LC-MS/MS for measuring vitamin D3-3-sulfate (VitD3-S) and 25-hydroxyvitamin D3-3-sulfate (25OHD3-S) specifically in human breastmilk. The resulting method uses methanol to precipitate protein and solid phase extraction to prepare the samples for LC-MS/MS. The limits of quantification for analytes in solvent were 0.23 ng/mL VitD3-S and 0.2 ng/mL 25OHD3-S. Various experiments observed concentrations ranging 0.53 to 1.7 ng/mL VitD3-S and ≤ 0.29 ng/mL 25OHD3-S. Both analytes were present in aqueous skim milk, demonstrating the enhanced aqueous solubility of these vitamin D sulfates. In conclusion, we describe an effective method for measuring VitD3-S and 25OHD3-S in breastmilk by LC-MS/MS.

Global Health Disparities in Childhood Rickets

Nutritional rickets is a global health problem reflecting both historical and contemporary health disparities arising from racial, ethnic, environmental, and geopolitical circumstances. It primarily affects marginalized populations and can contribute to long-term morbidity. Deficits in bone health in childhood may also contribute to osteomalacia/osteoporosis. Solutions require a global public health approach.

Bone Material Properties in Bone Diseases Affecting Children

PURPOSE OF REVIEW

Metabolic and genetic bone disorders affect not only bone mass but often also the bone material, including degree of mineralization, matrix organization, and lacunar porosity. The quality of juvenile bone is moreover highly influenced by skeletal growth. This review aims to provide a compact summary of the present knowledge on the complex interplay between bone modeling and remodeling during skeletal growth and to alert the reader to the complexity of bone tissue characteristics in children with bone disorders.

RECENT FINDINGS

We describe cellular events together with the characteristics of the different tissues and organic matrix organization (cartilage, woven and lamellar bone) occurring during linear growth. Subsequently, we present typical alterations thereof in disorders leading to over-mineralized bone matrix compared to those associated with low or normal mineral content based on bone biopsy studies. Growth spurts or growth retardation might amplify or mask disease-related alterations in bone material, which makes the interpretation of bone tissue findings in children complex and challenging.

Treatment of vitamin D deficiency in children

INTRODUCTION

Vitamin D deficiency affects from 10% to 50% in various pediatric population groups and causes life-threatening hypocalcemia in infants, crippling rickets in infants and children, and increased risk of subsequent adult metabolic and neurologic problems.

AREAS COVERED

An English language literature search of PubMed was performed since 1940 as were the authors' personal literature collections. References identified in the reviewed literature are considered.

DIAGNOSIS

The diagnosis of vitamin D deficiency is based on serum 25-hydroxyvitamin D levels. Clinical features of rickets include bone deformities and elevated alkaline phosphatase. Most children and adolescents who are biochemically vitamin D deficient do not have specific symptoms or signs of deficiency.

PREVENTION

Prevention of vitamin D deficiency is via exposure to sunshine, food and beverage fortification, and dietary supplementation.

TREATMENT

Effective treatment of vitamin D deficiency is via oral or injectable administration of vitamin D. Dosing and duration of vitamin D therapy have been described for healthy children and for children with underlying medical conditions, but recommendations vary.

EXPERT OPINION

Further investigation is needed to determine long-term non-skeletal effects of childhood vitamin D deficiency, benefits of supplementation in asymptomatic individuals with biochemical vitamin D deficiency, and appropriate screening for vitamin D deficiency in asymptomatic children and adolescents.

Clinical Profile, Intensive Care Needs and Outcome of Children with Dilated Cardiomyopathy Associated with Vitamin D Deficiency: A 5-year PICU Experience

Aim

To describe the clinical profile, treatment details, intensive care needs, and long-term outcome of children with dilated cardiomyopathy (DCM) associated with Vitamin D deficiency (VDD).

Materials and methods

Case records of 14 children with DCM associated with VDD [25(OH)D3 levels <20 ng/mL] admitted to the pediatric intensive care unit (PICU) of a tertiary care teaching hospital between January 2017 and December 2021 were retrospectively analyzed for clinical features, echocardiographic findings, treatment details, intensive care needs, and outcomes.

Results

The median (IQR) age was 6 (2-9) months and 71% (n=10) were males. The common modes of presentation included respiratory distress or failure (78.6%), congestive cardiac failure (71.4%), cardiogenic shock (37.5%), and seizures and encephalopathy (14.3% each). The median (IQR) serum calcium was 8.7 (7-9.5) mg%, ionized calcium 0.7 (0.7-1.1) mmol/L, alkaline phosphatase 343 (316-415) IU/L, phosphate 3.5 (2.6-4.5) mg%, PTH 115 (66-228) pg/mL, and 25(OH)D3 5 (3-7) ng/mL. The median (IQR) left ventricular ejection fraction (LVEF) at admission was 22 (17-25)%. The treatment included intravenous calcium infusion (35.7%), vitamin D supplementation in all (57.1% parenteral and 42.9% oral), mechanical ventilation (35.7%), and vasoactive drugs (57.1%). There was no mortality. The median (IQR) duration of PICU and hospital stay was 76 (31-98) hours and 6 (4.7-10) days, respectively. Out of 14 children, 10 (71.4%) were followed-up till median (IQR) of 10 (7-58) months. All were asymptomatic and had normal LEVF (except one had residual moderate mitral regurgitation).

Conclusion

Vitamin D deficiency is a potentially treatable and reversible cause of DCM in children.

How to cite this article

Kumar S, Randhawa MS, Angurana SK, Nallasamy K, Bansal A, Kumar MR, et al. Clinical Profile, Intensive Care Needs and Outcome of Children with Dilated Cardiomyopathy Associated with Vitamin D Deficiency: A 5-year PICU Experience. Indian J Crit Care Med 2023;27(7):510-514.

Nutritional rickets presenting with developmental regression: a rare presentation of rickets

Rickets is a disorder of defective mineralisation of the growth plate. Vitamin D deficiency remains the leading cause of nutritional rickets worldwide.We present the case of a 3.5-year-old breastfed boy who presented with dental abscess when a history of developmental regression was noted. Clinical assessment revealed hypotonia, poor growth and stunting. Biochemistry identified hypocalcaemia (1.63mmol/L, [normal range (NR) 2.2-2.7mmol/L]), severe vitamin D deficiency (25hydroxyvitamin D 5.3nmol/L, [NR > 50nmol/L]) with secondary hyperparathyroidism (Parathormone 159pmol/L, [NR 1.6-7.5pmol/L]) and rickets on radiographs. Growth failure screening suggested hypopituitarism with central hypothyroidism and low IGF1 at baseline, however, dynamic tests confirmed normal axis. Management included nasogastric nutritional rehabilitation, cholecalciferol and calcium supplementation and physiotherapy. A good biochemical response in all parameters was observed within 3 weeks and reversal of developmental regression by 3 months from treatment. Developmental regression as a presentation of nutritional rickets is rare and requires a high index of suspicion.

Vitamin D deficiency and anatomical region alters porcine growth plate properties

Ossification of growth plate cartilage mediates longitudinal extension of long bones. Biomechanical and biochemical disruptions of growth plate function may lead to abnormal bone growth. In humans and animals, severe dietary vitamin D deficiency can lead to rickets which features growth plate widening, resulting in abnormalities in growth. However, effects of marginal vitamin D deficiencies on growth plates are not well understood. The purpose of this study was to examine the effects of a vitamin D deficient diet in the 26-day nursery phase on mechanical properties (ultimate normal stress, ultimate shear stress, ultimate strain, and tangent modulus) of porcine growth plate. Standard uniaxial tensile tests were applied on bone-growth plate-bone sections and the total stress was decomposed into normal stress and shear stress. Ultimate shear stress and ultimate strain traits were lower in the vitamin D deficient group than in the control. Regional differences were observed in all four variables. Ultimate normal stress was higher in the anterior region, which was consistent with a previous study. Sex differences were detected in ultimate normal stress, which was higher in females than in males. Interestingly, the classical finding of growth plate widening seen in severe vitamin D deficiency was not observed in the pigs with marginal vitamin D deficiency utilized in this study.

Bone Matrix Mineralization and Response to Burosumab in Adult Patients With X-Linked Hypophosphatemia: Results From the Phase 3, Single-Arm International Trial

X-linked hypophosphatemia (XLH) is characterized by excess fibroblast growth factor 23 (FGF23) secretion, renal phosphate wasting, and low 1,25(OH)₂ D₃ . Adult patients present with osteomalacia, hypomineralized periosteocytic lesions, bone fragility, and pain. Burosumab is a fully human monoclonal FGF23 antibody approved for XLH treatment. UX023-CL304 was an open-label, phase 3 study investigating the effects of burosumab on osteomalacia in adults with XLH, who remained untreated at least 2 years prior enrollment. Here, we present the effect of burosumab on bone material properties. We analyzed transiliac bone biopsy samples from 11 individuals before and after 48 weeks of subcutaneous burosumab treatment (1.0 mg/kg administered every 4 weeks). We used quantitative backscattered electron imaging (qBEI) and Fourier transform infrared imaging (FTIRI) to assess bone mineralization density distribution (BMDD), mineralized bone volume, properties of the organic matrix, and size of periosteocytic lesions. The outcomes were compared with reference values from healthy adults and with four XLH patients either untreated or treated by conventional therapy. Prior to burosumab, the average mineralization in cancellous bone was lower than in healthy reference. CaLow, the fraction of lowly mineralized matrix, and CaHigh, the fraction of highly mineralized matrix, were both elevated resulting in a broad heterogeneity in mineralization (CaWidth). Burosumab resulted in a decrease of CaHigh toward normal range, whereas CaLow and CaWidth remained elevated. The mineralized bone volume was notably increased (+35.9%). The size of the periosteocytic lesions was variable but lower than in untreated XLH patients. FTIRI indicated decreased enzymatic collagen crosslink ratio heterogeneity. In summary, matrix mineralization in XLH is very heterogeneous. Highly mineralized regions represent old bone packets, probably protected from osteoclastic resorption by osteoid seams. The concomitant decrease of highly mineralized matrix, persistence of lowly mineralized matrix, and increase in mineralized bone volume after burosumab suggest a boost in mineralization of preexisting unmineralized or very lowly mineralized matrix, providing a potential explanation for previously observed improved osteomalacia. © 2022 American Society for Bone and Mineral Research (ASBMR).

Nutritional rickets and vitamin D deficiency: consequences and strategies for treatment and prevention

INTRODUCTION

Rickets is typically characterized by bone deformities due to defective bone mineralization and chondrocyte maturation in growing bones. However, infantile rickets often goes unrecognized, because the skeletal abnormalities are more subtle and often can only be detected radiologically. Nutritional rickets is a major public health concern in several regions worldwide. It is most commonly caused by vitamin D and/or calcium deficiency.

AREA COVERED

We provide an overview of historical perspective, epidemiology, and pathophysiology of nutritional rickets. Additionally, we outline diagnostic approaches and highlight challenges in radiographic diagnosis of rickets. Finally, we present strategies for prevention and treatment of rickets.

EXPERT OPINION

Despite the evidence from clinical databases that rickets is a rare disease, it is likely that rickets is clinically underdiagnosed as studies designed to screen healthy children for radiographic evidence of rickets reported surprisingly much higher prevalence. It has been reported that some of the radiologic features of rickets can be misinterpreted as fractures. To prevent nutritional rickets, most if not all infants and young children, should receive vitamin D from formulas and foods that are fortified with vitamin D or supplementation to achieve a serum 25-hydroxyvitamin D of at least 20 ng/mL as recommended by the Institute of Medicine. It has been recommended by the Endocrine Society that to achieve maximum bone health for children and adults, a serum concentration of 25-hydroxyvitamin D should be at least 30 ng/mL and preferably 40-60 ng/mL. Pregnant women who are unable to obtain an adequate amount of vitamin D from sunlight exposure and natural and fortified diets should take a vitamin D supplement of 1500-2000 IUs daily as recommended by the Endocrine Society since it has been demonstrated that 600 IUs daily will not maintain a circulating 25-hydroxyvitamin D of at least 20 ng/mL and most pregnant women. If lactating women take approximately 6400 IUs of vitamin D daily, they provide enough vitamin D in their milk to satisfy their infant's requirement thereby preventing rickets.

Implementation strategies for improving vitamin D status and increasing vitamin D intake in the UK: current controversies and future perspectives: proceedings of the 2nd Rank Prize Funds Forum on vitamin D

A multi-disciplinary expert group met to discuss vitamin D deficiency in the UK and strategies for improving population intakes and status. Changes to UK Government advice since the 1st Rank Forum on Vitamin D (2009) were discussed, including rationale for setting a reference nutrient intake (10 µg/d; 400 IU/d) for adults and children (4+ years). Current UK data show inadequate intakes among all age groups and high prevalence of low vitamin D status among specific groups (e.g. pregnant women and adolescent males/females). Evidence of widespread deficiency within some minority ethnic groups, resulting in nutritional rickets (particularly among Black and South Asian infants), raised particular concern. Latest data indicate that UK population vitamin D intakes and status reamain relatively unchanged since Government recommendations changed in 2016. Vitamin D food fortification was discussed as a potential strategy to increase population intakes. Data from dose-response and dietary modelling studies indicate dairy products, bread, hens' eggs and some meats as potential fortification vehicles. Vitamin D3 appears more effective than vitamin D2 for raising serum 25-hydroxyvitamin D concentration, which has implications for choice of fortificant. Other considerations for successful fortification strategies include: (i) need for 'real-world' cost information for use in modelling work; (ii) supportive food legislation; (iii) improved consumer and health professional understanding of vitamin D's importance; (iv) clinical consequences of inadequate vitamin D status and (v) consistent communication of Government advice across health/social care professions, and via the food industry. These areas urgently require further research to enable universal improvement in vitamin D intakes and status in the UK population.

Verminderte Mineralisation des Knochens: Rachitis und Osteomalazie

Die Mineralisation der Wachstumsfuge und des Knochens benötigt suffiziente Mengen an Kalzium und Phosphat, um ein adäquates Körperwachstum und eine adäquate Knochenstärke zu gewährleisten. Bei Mangelzuständen nehmen Härte und Stärke des Knochens ab (Osteomalazie), mit typischen Veränderungen an der Wachstumsfuge (Rachitis). Die vermeidbaren Komplikationen einer erworbenen Rachitis können lebensbedrohlich sein und sind auch deshalb ein global wichtiges Public-Health-Thema. Typische klinische Zeichen, Laborparameter und radiologische Veränderungen sollten zur unverzüglichen Diagnose führen. Erbliche und erworbene Formen der Rachitis wie X‑chromosomale Hypophosphatämie oder Hypophosphatasie werden, wie oftmals bei seltenen Erkrankungen, spät diagnostiziert. Diagnose, Therapie und Management von Rachitiden sollten durch tertiäre kinderosteologische Spezialisten erfolgen, die in internationalen „Rare-diseases“-Netzwerken arbeiten und in enger Kooperation mit Selbsthilfegruppen stehen.

Influence of maternal socioeconomic deprivation and living environment on newborn bloodspot 25-hydroxyvitamin D levels

Objectives

Vitamin D deficiency in neonates can have life-threatening consequences, hence the knowledge of risk factors is essential. This study aimed to explore the effect of maternal socioeconomic status (SES) on newborn 25-hydroxyvitamin D (25OHD) concentrations.

Design

Over two 1-week periods (winter and summer of 2019), 3000 newborn heel prick dried blood spots (DBS) and additional data of newborns, from a regional newborn screening laboratory (52° N) in the West Midlands, UK, were gathered. Post code was replaced with lower layer super output area (LSOA). Index of Multiple Deprivation (IMD) quintiles for the corresponding LSOA was used to assess SES [quintile one (Q1): most deprived 20%, quintile five (Q5): least deprived 20%]. Each of the seven domains of deprivation were examined (income, employment, education, health, barriers to housing and services, crime and living environment). 25OHD was measured on 6mm sub-punch from DBS using quantitative liquid chromatography tandem mass spectrometry and equivalent plasma values were derived.

Results

In total 2999 (1500 summer-born, 1499 winter-born) newborn DBS (1580 males) were analysed. Summer-born newborns had significantly higher 25OHD (IQR) concentrations [49.2 (34.3; 64.8) nmol/l] than winter-born newborns [29.1 (19.8; 40.6) nmol/l, p<0.001].25OHD levels varied significantly between the different IMD quintiles in the whole (p<0.001) and summer-born cohort (p<0.001), but not in the winter-born cohort (p=0.26), whereby Q1 had the lowest 25OHD concentrations. Among the domains of deprivation, living environment had a significant influence on 25OHD levels (β=0.07, p=0.002). In this subdomain, 25OHD levels varied significantly between quintiles in the whole (p<0.001) and summer-born cohort (mean 25OHD Q1 46.45 nmol/l, Q5 54.54 nmol/l; p<0.001) but not in the winter-born cohort (mean 25OHD Q1 31.57 nmol/l, Q5 31.72 nmol/l; p=0.16). In a regression model, living environment was still significant (p=0.018), albeit less than season of birth and ethnicity.

Conclusion

Among the seven domains of deprivation, maternal living environment had the greatest effect on newborn 25OHD levels. Whilst improved living environment positively influenced vitamin D status in the summer-born babies, winter-born had low 25OHD levels irrespective of the environment. Strategies such as enhanced supplementation and food fortification with vitamin D should be considered to overcome the non-modifiable main risk factors for vitamin D deficiency.

Serum Vitamin D Insufficiency in Hospitalized Full-Term Neonates at a Tertiary Hospital in Eastern China

OBJECTIVE

This study explored the status of serum vitamin D in hospitalized full-term neonates at a tertiary hospital in eastern China.

METHODS

A prospective study was conducted among 471 hospitalized full-term neonates at the Children's Hospital of Soochow University between January 1 and June 20, 2020. Perinatal clinical data, serum 25-hydroxyvitamin D (25(OH)D₃), laboratory examinations, serum calcium levels, and immune function were obtained and analyzed. We explored and analyzed the risk factors for vitamin D insufficiency or deficiency, and we also attempted to determine correlations between vitamin D and its influence on immunity.

RESULTS

The mean serum 25(OH)D₃ was 33.65±6.07ng/ml.The prevalence of vitamin D insufficiency was 28.24%,vitamin D sufficiency was 71.76%, there was no vitamin D deficiency. The serum 25-(OH)D₃ in singleton neonate was higher than twins or multiple infants (t = -10.918, P = 0.000). The serum 25-(OH)D₃ were higher in neonates who born in spring and summer than in winter (H = 13.443, P = 0.001). The serum 25-(OH)D₃ in appropriate for gestational age (AGA) and large for gestational age (LGA) neonates were higher than small for gestational age (SGA) (H = 7.686, P = 0.021). The serum 25-(OH)D₃ were higher in neonates whose mothers had no underlying diseases than those with certain immunological and infectious diseases (F = 12.417, P = 0.000). The serum 25-(OH)D₃ in neonates whose mothers had none or one perinatal complication were higher than those with two or more (F = 13.299, P = 0.000). The neonates with eosinophils ≤5% or normal platelet counts or serum Ca⁺⁺ ≥0.9 mmol/L have higher serum 25-(OH)D₃. Neonates born in winter were at risk for vitamin D insufficiency, and the incidence of infectious pneumonia, sepsis, cytomegalovirus infection, and hypocalcemia in the vitamin D insufficiency group were higher than sufficiency group (P < 0.05). The serum CD3+, CD3+CD4+, and IgA levels in vitamin D sufficiency neonates were significantly higher than those in insufficiency group (P < 0.05).

CONCLUSION

The prevalence of vitamin D insufficiency was 28.24%, and birth in winter was a risk factor for vitamin D insufficiency in hospitalized full-term neonates in Suzhou area. Neonates with infectious pneumonia, sepsis, cytomegalovirus infection, and hypocalcemia exhibited a high risk of vitamin D insufficiency. The serum CD3⁺, CD3⁺CD4⁺, and IgA levels in neonates with vitamin D insufficiency were lower.

The burden of vitamin D deficiency in household members of children presenting with symptomatic vitamin D deficiency

BACKGROUND

Micronutrient deficiencies are common among household/family members due to shared lifestyle and dietary habits. The extent of biochemical abnormalities in household members of children presenting with symptomatic vitamin D deficiency remains unknown.

AIM

Investigate the prevalence of vitamin D deficiency and biochemical osteomalacia in the mothers and siblings of children presenting with symptomatic vitamin D deficiency.

METHODS

All mothers and sibling of children referred to a single tertiary endocrine centre between January 2018 and December 2021, with symptomatic vitamin D deficiency were investigated prospectively for vitamin D deficiency [defined as 25 hydroxyvitamin D (25OHD) < 30nmol/L] and biochemical osteomalacia [vitamin D deficiency and elevated alkaline phosphatase (ALP) and/or parathormone (PTH)] as per clinical guidelines.

REULTS

Ninety-seven family members (68 siblings and 29 mothers) of 29 index cases (median age 1.7 years, 55.5% male) were investigated. The majority (65.5%, n=19) were of Asian ethnic background. The mean (SD) 25OHD levels of the index, maternal and sibling cohorts were 15 (10), 15 (7) and 20 (10) nmol/L respectively. Vitamin D deficiency was noted in 93% of the maternal and 79% of the sibling cohorts. Biochemical osteomalacia was present in 72% of the maternal and 79% of the sibling cohorts. Mothers of infants had significantly lower mean 25OHD levels compared to mothers of older children [11 (n=12) vs 18 nmol/L (n=17) respectively, p=0.006)], most of whom were symptomatic (66.6%, n=8/12). None of the mothers had hypocalcaemia. Among the 10% (n=7) of the siblings with hypocalcaemia, 86% (n=6/7) had concurrent dietary calcium deficiency and 71.4% (n= 5/7) reported symptoms in retrospect. Hypocalcaemic siblings had significantly lower 25OHD (7 vs 15 nmol/L, p<0.001), higher PTH (175 vs 58 ng/L, p<0.001) and ALP (846 vs 318 IU/L, p<0.001), respectively compared to normocalcaemic siblings.

CONCLUSIONS

In view of the substantial morbidity uncovered in household/family members of children diagnosed with symptomatic vitamin D deficiency, we recommend universal supplementation of all risk groups. Biochemical testing and treatment is indicated to replenish stores only in those at highest risk such as mothers of infants, individuals with concurrent dietary calcium deficiency and those with clinical symptoms.

Improving Vitamin D Intake in Young Children-Can an Infographic Help Parents and Carers Understand the Recommendations?

Vitamin D deficiency is a serious public health issue in the United Kingdom. Those at increased risk, such as pregnant women, children under 5 years and people from ethnic groups with dark skin, are not all achieving their recommended vitamin D. Effective vitamin D education is warranted. A qualitative study was undertaken to evaluate the acceptability and understanding of a vitamin D infographic, developed using recommendations from previous research. Fifteen parents/carers, recruited through local playgroups and adverts on popular parent websites, participated in focus groups and telephone interviews. The majority were female, White British and educated to degree level. A thematic analysis methodology was applied. The findings indicated that understanding and acceptability of the infographic were satisfactory, but improvements were recommended to aid interpretation and create more accessible information. These included additional content (what vitamin D is; other sources; its health benefits; methods/doses for administration and scientific symbols used) and improved presentation (eye-catching, less text, simpler language, more images and a logo). Once finalized, the infographic could be a useful tool to educate families around vitamin D supplementation guidelines, support the UK Healthy Start vitamins scheme and help improve vitamin D status for pregnant and lactating women and young children.

Serum 25-hydroxyvitamin D requirements to prevent nutritional rickets in Nigerian children on a low-calcium diet-a multivariable reanalysis

BACKGROUND

Nutritional rickets is believed to result from the interaction of inadequate serum 25-hydroxyvitamin D [25(OH)D] concentration and dietary calcium intake, but this interaction has not been confirmed in children with rickets. Determining the vitamin D requirements to prevent nutritional rickets has been thwarted by inconsistent case definition, inadequate adjustment for calcium intake and other confounders, and 25(OH)D assay variability.

OBJECTIVES

To model the 25(OH)D concentration associated with nutritional rickets in calcium-deprived Nigerian children, adjusted for confounding factors, and develop a general approach to define vitamin D status while accounting for calcium intake.

METHODS

Logistic regression was used to model the association of serum 25(OH)D with having rickets adjusted for calcium intake in a reanalysis of a case-control study in Nigerian children. The matching variables age, sex, weight-for-age z score, and 4 additional significant variables were selected [religion, age began walking, phosphorus intake, and the 25(OH)D × calcium intake interaction] using a rigorous 7-step algorithm.

RESULTS

Cases had significantly (P < 0.0001) lower mean ± SD 25(OH)D than controls (33 ± 13 compared with 51 ± 16 nmol/L, respectively), whereas cases and controls had similarly (P = 0.81) low mean dietary calcium intakes (216 ± 88 and 213 ± 95 mg/d, respectively). There was a significant interaction between 25(OH)D and calcium intake [coefficient (95% CI): -0.0006 (-0.0009, -0.0002)]. Accordingly, as calcium intake increased from 130 to 300 mg/d, the adjusted odds of having rickets decreased dramatically with increasing 25(OH)D such that at 200 mg/d, the adjusted odds of having rickets at 47.5 nmol/L was 0.80, whereas it was 0.2 at 62.5 nmol/L. Moreover, at a calcium intake of 300 mg/d, the adjusted odds was 0.16 at a 25(OH)D concentration of 47.5 nmol/L and 0.02 at 62.5 nmol/L.

CONCLUSIONS

The vitamin D requirement to prevent nutritional rickets varies inversely with calcium intake and vice versa. Also, application of multivariable modeling is essential in defining vitamin D requirements.

Epidemiologic Data of Vitamin D Deficiency and Its Implication in Cardio-Cerebrovascular Risk in a Southern Italian Population

Background

Vitamin D (25(OH)D) deficiency is a prevalent condition worldwide. However, the highest prevalence rates of 25(OH)D deficiency have been attributed to regions with higher latitude. A close association between 25(OH)D and cardio-cerebrovascular (CCV) risk factors and major health problems has been identified.

Aim

To establish the prevalence of 25(OH)D deficiency and to investigate the relationship between 25(OH)D levels and CCV risk factors (blood cholesterol, triglycerides, glucose concentrations, body mass index, and systolic and diastolic blood pressure) in a cohort representative of Southern Italy.

Methods

The prevalence of 25(OH)D levels was evaluated in 1200 subjects aged 25-74 years (600 males and 600 females), enrolled in the "VIP" (from Italian for Irno Valley Prevention) Project, whereas multiple linear regression analysis was used to determine the relationship between 25(OH)D levels and CCV risk factors.

Results

Only 13.3% of females and 11.1% of males showed adequate serum concentrations of 25(OH)D (≥30 ng/ml), while 59.3% of females and 55.1% of males showed 25(OH)D deficient levels (<20 ng/ml). We observed an independent association between 25(OH)D concentrations and metabolic syndrome score, LDL cholesterol, HDL cholesterol, and corrected QT (cQT).

Conclusions

We report a high prevalence of 25(OH)D deficiency across the largest Italian adult population studied so far and, in particular, the first across Southern Italy; furthermore, we provide data on the association between 25(OH)D deficiency and higher CCV risk factors.

Vitamin D, rickets and child abuse: controversies and evidence

Suboptimal vitamin D status is a global health issue that affects children and adults worldwide. The prevalence of vitamin D deficiency and insufficiency has been well documented in the pediatric population in the United States. Although vitamin D deficiency is common, radiographic findings are uncommon and can be subtle. Additionally, because of the high prevalence of pediatric vitamin D insufficiency, it is commonly identified in young children with fractures. However, the majority of pediatric fractures are caused by trauma to healthy bones. Some, especially in infants and toddlers, are caused by non-accidental trauma. A small percentage is related to medical disease, including those associated with disorders of collagen, disorders of mineralization, and non-fracture mimics. Despite the scientific evidence, among disorders of mineralization, non-rachitic disorders of vitamin D have become a popular non-scientific theory to explain the fractures identified in abused children. Although infants and young children with rickets can fracture bones, the vast majority of fractures identified in abused infants are not caused by bone disease. Here we present a review of the literature on bone disease in the setting of accidental and non-accidental trauma. This context can help physicians remain vigilant about identifying vulnerable young children whose injuries are caused by non-accidental trauma.

Nutritional rickets & osteomalacia: A practical approach to management

Defective mineralization of the growth plate and preformed osteoid result in rickets and osteomalacia, respectively. The leading cause of rickets worldwide is solar vitamin D deficiency and/or dietary calcium deficiency collectively termed as nutritional rickets. Vitamin D deficiency predominates in high-latitude countries in at-risk groups (dark skin, reduced sun exposure, infants and pregnant and lactating women) but is emerging in some tropical countries due to sun avoidance behaviour. Calcium deficiency predominates in tropical countries, especially in the malnourished population. Nutritional rickets can have devastating health consequences beyond bony deformities (swollen wrist and ankle joints, rachitic rosary, soft skull, stunting and bowing) and include life-threatening hypocalcaemic complications of seizures and, in infancy, heart failure due to dilated cardiomyopathy. In children, diagnosis of rickets (always associated with osteomalacia) is confirmed on radiographs (cupping and flaring of metaphyses) and should be suspected in high risk individuals with the above clinical manifestations in the presence of abnormal blood biochemistry (high alkaline phosphatase and parathyroid hormone, low 25-hydroxyvitamin D and calcium and/or low phosphate). In adults or adolescents with closed growth plates, osteomalacia presents with non-specific symptoms (fatigue, malaise and muscle weakness) and abnormal blood biochemistry, but only in extreme cases, it is associated with radiographic findings of Looser's zone fractures. Bone biopsies could confirm osteomalacia at earlier disease stages, for definitive diagnosis. Treatment includes high-dose cholecalciferol or ergocalciferol daily for a minimum of 12 wk or stoss therapy in exceptional circumstances, each followed by lifelong maintenance supplementation. In addition, adequate calcium intake through diet or supplementation should be ensured. Preventative approaches should be tailored to the population needs and incorporate multiple strategies including targeted vitamin D supplementation of at-risk groups and food fortification with vitamin D and/or calcium. Economically, food fortification is certainly the most cost-effective way forward.

Failure of national antenatal vitamin D supplementation programme puts dark skinned infants at highest risk: A newborn bloodspot screening study

OBJECTIVES

To determine the prevalence of vitamin D deficiency on dried blood spots (DBS) obtained at newborn blood spot screening (NBS) and thereby test the efficacy of the UK national antenatal supplementation programme in an increasingly ethnically diverse English population. To evaluate the seasonal and ethnic variation in neonatal plasma 25 hydoxyvitamin D (25OHD) and its determinants.

DESIGN

Three thousand random DBS samples received at a single regional newborn screening laboratory (52° N) over two one-week periods, one in winter (February 2019) and one in summer (August 2019), were collected. Data was collected from NBS cards on birth weight, gestational age, maternal age, ethnicity, and post code which was replaced with index of multiple deprivation (IMD). 25OHD concentrations were measured on 6 mm sub-punch from DBS using quantitative liquid chromatography tandem mass spectrometry adjusted to equivalent plasma values. 25OHD variation with season was assessed using Mann-Whitney U test and ethnic groups compared using Kruskal-Wallis test. Linear regression was used to assess the determinants of 25OHD concentrations.

RESULTS

25OHD measurements were available in 2999 (1580 males) subjects [1499 winter-born and 1500 summer-born]. The majority were white British (59.1%) and born at term (mean ± SD gestational age of 38.8 ± 1.8 weeks) with a mean (±SD) birth weight of 3306 (±565) grams. The overall prevalence of vitamin D deficiency [25OHD<30 nmol/L (12 μg/L)] was 35.7% (n = 1070) and insufficiency [30-50 nmol/L (12-20 μg/L)] 33.7% (n = 1010). The median (IQR) 25OHD concentration was significantly lower in the winter-born compared to summer-born [29.1 (19.8, 40.6) vs 49.2 (34.3, 64.8) nmol/L respectively; p < 0.001]. Across both seasons, when compared to white British babies (41.6 nmol/L), the median 25OHD concentrations were significantly lower in babies of black (30.3 nmol/L; p < 0.001), Asian (31.3 nmol/L; p < 0.001), any other mixed (32.9 nmol/L; p < 0.001), mixed white and black (33.7 nmol/L; p < 0.05) and any other white (37.7 nmol/L; p < 0.05) ethnicity. The proportion of deficiency was also higher in babies of Asian (48%), black (47%) and mixed ethnicity (38-44%) compared to any other white (34%) or white British (30%) ethnicity. Season of birth, ethnicity, gestation and maternal age accounted for almost 24% of the variation in 25OHD concentrations.

CONCLUSION

The current UK antenatal supplementation programme fails to protect newborns from vitamin D deficiency, especially those from minority ethnic groups who are at high risk of vitamin D deficiency. Nearly 70% of all newborns and 85% of winter-borns had 25OHD concentrations below 50 nmol/L (20 μg/L). Almost 50% of babies of Black or Asian origin were deficient at birth, which explains their high risk of hypocalcaemic complications and rickets if left unsupplemented. Our findings call for an immediate review of the delivery of antenatal and infant vitamin D supplementation programmes and implementation of food fortification in the long term.

Differences and determinants of vitamin D deficiency among UK biobank participants: A cross-ethnic and socioeconomic study

BACKGROUND

The public health relevance of true vitamin D deficiency is undisputed, although controversy remains regarding optimal vitamin D status. Few contemporary cross-ethnic studies have investigated the prevalence and determinants of very low 25-hydroxyvitamin D [25(OH)D] concentrations.

METHODS

We conducted cross-ethnic analyses on the prevalence and determinants of vitamin D deficiency (25(OH)D ≤ 25 nmol/L) using data from 440,581 UK Biobank participants, of which 415,903 identified as White European, 7880 Asian, 7602 Black African, 1383 Chinese, and 6473 of mixed ancestry. Determinants of vitamin D deficiency were examined by logistic regression.

RESULTS

The prevalence of vitamin D deficiency was highest among participants of Asian ancestry (57.2% in winter/spring and 50.8% in summer/autumn) followed by those of Black African ancestry (38.5% and 30.8%, respectively), mixed (36.5%, 22.5%), Chinese (33.1%, 20.7%) and White European ancestry (17.5%, 5.9%). Participants with higher socioeconomic deprivation were more likely to have 25(OH)D deficiency compared to less deprived participants (P = <1 × 10^-300); this pattern was more apparent among those of White European ancestry and in summer (P_interaction ≤6.4 × 10^-5 for both). In fully-adjusted analyses, regular consumption of oily fish was associated with reduced odds of vitamin D deficiency across all ethnicities, while outdoor-time in summer was less effective for Black Africans (OR 0.89, 95% CI 0.70, 1.12) than White Europeans (OR 0.40, 95% CI 0.38, 0.42).

CONCLUSIONS

Severe vitamin D deficiency remains an issue throughout the UK, particularly in lower socioeconomic areas. In some groups, levels of deficiency are alarmingly high with one-half of Asian and one-third of Black African ancestry populations affected across seasons.

KEY MESSAGES

The prevalence of vitamin D deficiency in the UK is alarming, with certain ethnic and socioeconomic groups considered particularly vulnerable.

Cost-Effectiveness of Vitamin D Supplementation in Pregnant Woman and Young Children in Preventing Rickets: A Modeling Study

Background: Literature on the cost of management of rickets and cost-effectiveness of vitamin D supplementation in preventing rickets is lacking. Methods: This study considered the cost-effectiveness of providing free vitamin D supplementation to pregnant women and children <4 years of age with varying degrees of skin pigmentation to prevent rickets in children. Estimates for the prevalence of rickets were calculated using all cases of rickets diagnosed in Central Manchester, UK and census data from the region. Cost of management of rickets were calculated using National Health Service, UK tariffs. The efficacy of vitamin D supplementation was based on a similar programme implemented in Birmingham. Quality of life was assessed using utility estimates derived from a systematic literature review. In this analysis the intervention was considered cost-effective if the incremental cost-effectiveness ratio (ICER) is below the National Institute for Health and Care Excellence, UK cost-effectiveness threshold of £20,000 per Quality-adjusted life year (QALY). Results: Fifty-seven patients (26 dark, 29 medium and 2 light skin tones) were managed for rickets and associated complications over 4-years. Rickets has an estimated annual incidence of 29·75 per 100,000 children <4 years of age. In the dark skin tone population vitamin D supplementation proved to be cost saving. In a medium skin tone population and light skin tone populations the ICER was £19,295 per QALY and £404,047 per QALY, respectively. Conclusion: Our study demonstrates that a vitamin D supplementation to prevent rickets is cost effective in dark and medium skin tone populations.

Investigation and management of hypocalcaemia

Hypocalcaemia is a common clinical scenario in children with a range of aetiological causes. It will often present with common symptoms but may occasionally be identified in an asymptomatic child. An understanding of the physiological regulation of plasma calcium is important in understanding the potential cause of hypocalcaemia and its appropriate management. The age of presentation will influence the likely differential diagnosis. We have presented a stepwise approach to the investigation of hypocalcaemia dependent on the circulating serum parathyroid hormone level at the time of presentation. The acute and long-term management of the underlying condition is also reviewed.

The economic case for prevention of population vitamin D deficiency: a modelling study using data from England and Wales

BACKGROUND

Vitamin D deficiency (VDD) affects the health and wellbeing of millions worldwide. In high latitude countries such as the United Kingdom (UK), severe complications disproportionally affect ethnic minority groups.

OBJECTIVE

To develop a decision-analytic model to estimate the cost effectiveness of population strategies to prevent VDD.

METHODS

An individual-level simulation model was used to compare: (I) wheat flour fortification; (II) supplementation of at-risk groups; and (III) combined flour fortification and supplementation; with (IV) a 'no additional intervention' scenario, reflecting the current Vitamin D policy in the UK. We simulated the whole population over 90 years. Data from national nutrition surveys were used to estimate the risk of deficiency under the alternative scenarios. Costs incurred by the health care sector, the government, local authorities, and the general public were considered. Results were expressed as total cost and effect of each strategy, and as the cost per 'prevented case of VDD' and the 'cost per Quality Adjusted Life Year (QALY)'.

RESULTS

Wheat flour fortification was cost saving as its costs were more than offset by the cost savings from preventing VDD. The combination of supplementation and fortification was cost effective (£9.5 per QALY gained). The model estimated that wheat flour fortification alone would result in 25% fewer cases of VDD, while the combined strategy would reduce the number of cases by a further 8%.

CONCLUSION

There is a strong economic case for fortifying wheat flour with Vitamin D, alone or in combination with targeted vitamin D3 supplementation.

Population-Based Incidence of Potentially Life-Threatening Complications of Hypocalcemia and the Role of Vitamin D Deficiency

OBJECTIVES

To determine the incidence of potentially life-threatening complications of hypocalcemia in infants and children in Olmsted County, Minnesota; and to determine if vitamin D deficiency contributed to these events and was, at the time of clinical presentation, considered as a possible cause.

STUDY DESIGN

In this population-based descriptive study, data were abstracted from the Rochester Epidemiology Project, a medical record linkage system covering 95% of patients in Olmsted County, Minnesota. Participants were children aged 0-5 years who resided in Olmsted County between January 1, 1996 and June 30, 2017, and who received diagnoses of seizures, cardiomyopathy, cardiac arrest, respiratory arrest, laryngospasm, and/or tetany. The incidence of hypocalcemia plus a potentially life-threatening complication was calculated.

RESULTS

Among 15 419 patients aged 0-5 years in Olmsted County during the study period, 1305 had eligible complications: 460 had serum calcium checked within 14 days of presentation and 85 had hypocalcemia. Patients were excluded when causes other than hypocalcemia likely triggered the complication, leaving 16 children whose complication was attributed to hypocalcemia. Three of these 16 patients had a serum 25-hydroxyvitamin D measurement and 2 were deficient (≤6 ng/mL [15 nmol/L]). Among children aged 0-5 years, the incidence of hypocalcemia plus a potentially life-threatening complication was 6.1 per 100 000 person-years (95% CI, 3.5-10.0).

CONCLUSIONS

Vitamin D deficiency is an underinvestigated cause of complications of hypocalcemia in children. Serum calcium and 25-hydroxyvitamin D should be measured in children with these complications to identify possibly life-threatening vitamin D deficiency.

Spot the silent sufferers: A call for clinical diagnostic criteria for solar and nutritional osteomalacia

Osteomalacia and rickets result from defective mineralization when the body is deprived of calcium. Globally, the main cause of osteomalacia is a lack of mineral supply for bone modeling and remodeling due to solar vitamin D and/or dietary calcium deficiency. Osteomalacia occurs when existing bone is replaced by unmineralized bone matrix (osteoid) during remodeling in children and adults, or when newly formed bone is not mineralized in time during modeling in children. Rickets occurs when hypomineralization affects the epiphyseal growth plate chondrocytes and adjacent bone metaphysis in growing children. Hence, osteomalacia co-exists with rickets in growing children. Several reports in the last decade highlight the resurgence of so-called "nutritional" rickets in the dark-skinned population living in high-income countries. However, very few studies have ever explored the hidden iceberg of nutritional osteomalacia in the population. Rickets presents with hypocalcaemic (seizures, tetany, cardiomyopathy), or hypophosphataemic complications (leg bowing, knock knees, rachitic rosary, muscle weakness) and is diagnosed on radiographs (cupping and fraying of metaphyses). In contrast, osteomalacia lacks distinctive, non-invasive diagnostic laboratory or imaging criteria and the clinical presentation is non-specific (general fatigue, malaise, muscle weakness and pain). Hence, osteomalacia remains largely undiagnosed, as a hidden disease in millions of dark-skinned people who are at greatest risk. Radiographs may demonstrate Looser's zone fractures in those most severely affected, however to date, osteomalacia remains a histological diagnosis requiring a bone biopsy. Biochemical features of high serum alkaline phosphatase (ALP), high parathyroid hormone (PTH) with or without low 25 hydroxyvitamin D (25OHD) concentrations are common to both rickets and osteomalacia. Here, we propose non-invasive diagnostic criteria for osteomalacia. We recommend a diagnosis of osteomalacia in the presence of high ALP, high PTH, low dietary calcium intake (<300 mg/day) and/or low serum 25OHD (<30 nmol/L). Presence of clinical symptoms (as above) or Looser's zone fractures should be used to reaffirm the diagnosis. We call for further studies to explore the true prevalence of nutritional osteomalacia in various populations, specifically the Black and Asian ethnic groups, in order to identify the hidden disease burden and inform public health policies for vitamin D/calcium supplementation and food fortification.

Micronutrient deficiencies and health-related quality of life: the case of children with vitamin D deficiency

OBJECTIVE

To explore the extent to which micronutrient deficiencies (MND) affect children's health-related quality of life (HRQoL), using vitamin D deficiency (VDD) as a case study.

DESIGN

Proxy valuation study to estimate the impact of VDD on the HRQoL of younger (0-4 years) and older (>4 years) children. We used the Child Health Utility 9 Dimension (CHU9D) questionnaire to estimate HRQoL for children within six VDD-related health states: 'hypocalcaemic cardiomyopathy', 'hypocalcaemic seizures', 'active rickets', 'bone deformities', 'pain and muscle weakness' and 'subclinical VDD'.

SETTING

Sampling was not restricted to any particular setting and worldwide experts were recruited.

PARTICIPANTS

Respondents were paediatric bone experts recruited through network sampling.

RESULTS

Thirty-eight experts completed the survey. The health state with the largest detrimental impact (mean score (se)) on children's HRQoL was hypocalcaemic cardiomyopathy (0·47 (0·02)), followed by hypocalcaemic seizures (0·50 (0·02)) and active rickets (0·62 (0·02) in young children; 0·57 (0·02) in older children). Asymptomatic VDD had a modest but noticeable negative impact on HRQoL, attributed mostly to tiredness in both age groups and pain in the older paediatric population.

CONCLUSIONS

Elicitation of HRQoL from clinical experts suggests a negative impact of VDD on HRQoL, even if there is no recognizable clinical manifestation. HRQoL data from populations of patients with MND will inform public health policy decisions. In some settings, routine collection of HRQoL data alongside national nutrition surveys may help capture the full burden of MND and prioritize resources towards effective prevention.

Vitamin D testing and treatment: a narrative review of current evidence

Vitamin D testing and treatment is a subject of controversial scientific discussions, and it is challenging to navigate through the expanding vitamin D literature with heterogeneous and partially opposed opinions and recommendations. In this narrative review, we aim to provide an update on vitamin D guidelines and the current evidence on the role of vitamin D for human health with its subsequent implications for patient care and public health issues. Vitamin D is critical for bone and mineral metabolism, and it is established that vitamin D deficiency can cause rickets and osteomalacia. While many guidelines recommend target serum 25-hydroxyvitamin D (25[OH]D) concentrations of ≥50 nmol/L (20 ng/mL), the minimum consensus in the scientific community is that serum 25(OH)D concentrations below 25-30 nmol/L (10-12 ng/mL) must be prevented and treated. Using this latter threshold of serum 25(OH)D concentrations, it has been documented that there is a high worldwide prevalence of vitamin D deficiency that may require public health actions such as vitamin D food fortification. On the other hand, there is also reason for concern that an exploding rate of vitamin D testing and supplementation increases costs and might potentially be harmful. In the scientific debate on vitamin D, we should consider that nutrient trials differ from drug trials and that apart from the opposed positions regarding indications for vitamin D treatment we still have to better characterize the precise role of vitamin D for human health.