La accidentada historia del descubrimiento de la vitamina D, en su primer centenario / The checkered history of the discovery of vitamin D, in its first centenary

El año 2022 marca el primer centenario del descubrimiento de la vitamina D, hallazgo que recompensó la prolongada búsqueda de la causa del raquitismo, su prevención y tratamiento. Al mismo tiempo puso en marcha importantes investigaciones relaciona-das con su biotransformación y el mecanismo de su acción antirraquítica, además de estudios sobre diversos efectos biológicos sin relación directa con su papel en la salud ósea. Esta breve revisión se limitará a delinear la prehistoria de la vitamina D y los diversos estudios, básicos y clínicos, que condujeron a su descubrimiento y caracterización química. (AU)

The year 2022 marks the centenary of the discovery of vitamin D, a breakthrough that rewarded the long search for the cause of rickets, its prevention and treatment. At the same time, it launched important investigations related to its biotransformation and the mechanism of its antirachitic action, as well as studies on various biological effects without direct relation to its role in bone health. This brief review will be limited to an outline of the prehistory of vitamin D and the various basic and clinical studies that led to its discovery and chemical characterization. (AU)

Arte, historia y endocrinología / Art, history and endocrinology

Las enfermedades han sido representadas en el arte desde tiempos remotos. Las obras pictóricas muchas veces nos muestran trastornos que aún no se constituían como una entidad. Observar estos cuadros a la luz de la historia de las enfermedades nos da una perspectiva enriquecedora que nos ayuda a entender mejor dichas patologías. Se comenta un caso clínico endocrinológico pediátrico, la historia probable y su descripción física. Se revisa la historia de cómo se llegó a dilucidar la enfermedad y las claves de su tratamiento.

Diseases have been represented in art since ancient times. Paintings often show us disorders that had not yet been described as a pathological entity. Looking at these pictures in the light of the history of the diseases gives us an enriching perspective that helps us to better understand those pathologies. On this background a pediatric endocrinological clinical case, the most probable history and the features of the physical examination are discussed. The history of how the disease was uncovered and the keys of its treatment are reviewed.

Rickets in white-eared opossums (Didelphis albiventris) / Raquitismo em gambás-de-orelha-branca (Didelphis albiventris)

Two young opossums were necropsied and diagnosed with rickets. This study aims to describe the clinical-pathological aspects of rickets in Didelphis albiventris. Macroscopically, the opossums presented kyphosis and scoliosis, lateral deviation of the limbs in varus, locomotion difficulty, and enlargement with softening of costochondral junctions (rickety rosary). Samples of bones and joints were processed for hematoxylin and eosin staining and Masson's trichrome. Microscopically, we observed thickening of the epiphyseal plate, characterized by irregular and multifocal proliferation of serialized and hypertrophic cartilage zones, which formed circular groups of large, dysplastic chondrocytes towards the spongy zone, often surrounded by non-mineralized osteoid tissue. In the cortical bone, there were pale eosinophilic zones around the Havers channels consistent with non-mineralized osteoid. The staining of Masson's trichrome evidenced the accumulation of osteoid tissue in cortical and trabecular bones. It is possible that a mixed cause of absorption deficiency of vitamin D3 associated with an unbalanced Ca:P diet based on lactose-free milk and fruits may have triggered the disease.(AU)

Dois gambás jovens foram necropsiados e diagnosticados com raquitismo. O objetivo do trabalho é descrever os aspectos clínico-patológicos de raquitismo em Didelphis albiventris. Macroscopicamente os gambás apresentaram cifose e escoliose, desvio lateral dos membros em varus, dificuldade de locomoção e alargamento com amolecimento das junções costocondrais (rosário raquítico). Amostras dos ossos e articulações foram processadas para coloração de hematoxilina e eosina e Tricrômico de Masson. Microscopicamente havia espessamento da placa epifisária, caracterizada pela proliferação irregular e multifocal das zonas de cartilagem seriada e hipertrófica, que formavam grupos circulares de condrócitos grandes, displásicos em direção a zona esponjosa frequentemente cercados por tecido osteoide não mineralizado. No osso cortical haviam zonas eosinofílicas pálidas ao redor dos canais de Havers consistentes com osteoide não mineralizado. A coloração de Tricrômico de Masson evidenciou o acúmulo de tecido osteoide no nosso cortical e trabecular. Acredita-se que uma causa mista de déficit de absorção de vitamina D3 associada a uma dieta desbalanceada em Ca:P a base de leite sem lactose e frutas tenha desencadeado a doença.(AU)

Vitamin D Toxicity / Toxicidade da Vitamina D

Abstract 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.

Resumo A suplementação de produtos alimentares com vitamina D foi fundamental para a erradicação do raquitismo no início do século XX nos Estados Unidos. Nos quase 100 anos subsequentes, o acúmulo de evidências vinculou a deficiência de vitamina D a uma variedade de desfechos, e isso tem levantado grande interesse público e conscientização dos benefícios à saúde da vitamina D. Os suplementos que contêm vitamina D estão agora amplamente disponíveis tanto nos países desenvolvidos quanto naqueles em desenvolvimento, e muitos estão na forma de formulações não regulamentadas, vendidas ao público com poucas orientações para uma administração segura. Juntos, isso contribuiu para uma transição na qual um aumento global dramático nos casos de toxicidade da vitamina D tem sido relatado. Médicos agora enfrentam o desafio de tratar essa condição que pode apresentar um espectro de complicações assintomáticas a agudas, com risco de vida. Este artigo considera dados atualizados sobre a toxicidade da vitamina D e estratégias de diagnóstico e manejo relevantes para a prática clínica.

Oral manifestations of renal tubular acidosis associated with secondary rickets: case report / Manifestações bucais da acidose tubular renal associada ao raquitismo secundário: relato de caso

ABSTRACT This report describes the oral manifestations of renal tubular acidosis (RTA) associated with secondary rickets and discusses the biological plausibility of these findings. The characteristic electrolyte changes during RTA or genetic mutations that trigger RTA may be responsible for impaired amelogenesis, dental malocclusion, impacted teeth, and absent lamina dura. This report reinforces the possibility of an association between RTA and the oral manifestations described.

RESUMO Este relato de caso descreve as manifestações bucais da acidose tubular renal (ATR) associada ao raquitismo secundário e discute a plausibilidade biológica desses achados. As alterações eletrolíticas características da ATR ou as mutações genéticas que a desencadeiam podem ser responsáveis pela amelogênese imperfeita, maloclusão dentária, dentes impactados e ausência de lâmina dura. Este relato reforça a possibilidade de uma associação entre ATR e as manifestações bucais descritas.

Normal physiological functions in two animal species with highly different vitamin d status compared to that of humans / Funciones fisiológicas normales en dos especies animales con estatus de vitamina d muy diferentes del actual en seres humanos

Mole rats live in permanent darkness, in networks of underground tunnels (which extend up to 1 km in the subsoil), excavated with their incisors, in warm and semi-arid areas of South Africa. Mole rats have an unusually impoverished vitamin D3 status with undetectable and low plasma concentrations of 25- hydroxyvitamin D3 and 1α,25-dihydroxyvitamin D3, respectively. They express 25-hydroxylase in the liver and 1-hydroxylase and 24-hydroxylase in their kidneys. The presence of specific receptors (VDR) was confirmed in the intestine, kidney, Harderʼs glands and skin. In spite of their poor vitamin D3 status, the apparent fractional intestinal absorption of calcium, magnesium and phosphate was high, always greater than 90%. Oral supplementation with cholecalciferol to mole rats did not improve the efficiency of gastrointestinal absorption of these minerals. Mole ratsdo not display the typical lesion of rickets: hypertrophic and radiolucent growth cartilages. Histological studies reported normal parameters of trabecular and cortical bone quality. Marmosets (monkeys of the New World) are not hypercalcaemic, eventhough they exhibit much higher levels of 25-hydroxyvitamin D3, 1α,25-dihydroxyvitamin D3 and parathyroid hormonethan that of rhesus monkeys and humans. Fed a high vitamin D3 intake (110 IU/day/100 g of body weight), a fraction of the experimental group was found to display osteomalacic changes in their bones: distinct increases in osteoid surface, relative osteoid volume, and active osteoclastic bone resorption. These findings suggest that some marmosets appears to suffer vitamin D-dependent rickets, type II. The maximum binding capacity of the VDR or the dissociation constant of VDR1α,25(OH)2D3 complex of mole rats and New World monkeys are distinctly different of VDR isolated from human cells. Health status of those species appears to be adaptations to the mutations of their VDR. Though rare, as mutations may occur at any time in any patient, the overall message of this review to clinicians may be: recent clinical studies strongly suggests that the normality of physiological functions might be a better indicator of the health status than the serum levels of vitamin D metabolites. (AU)

Las ratas topo viven en la oscuridad permanente, en redes de túneles subterráneos excavadas con sus incisivos (que se extienden hasta 1 km en el subsuelo), en áreas cálidas y semiáridas de Sudáfrica. Las ratas topo tienen un estatus de vitamina D3 inusualmente empobrecido con concentraciones plasmáticas indetectables de 25-hidroxivitamina D3 y bajas de 1α, 25-dihidroxivitamina D3. Poseen 25-hidroxilasa en el hígado y 1-hidroxilasa y 24-hidroxilasa en sus riñones. La presencia de receptores específicos (VDR) ha sido confirmada en el intestino, el riñón, las glándulas de Harder y la piel. A pesar de su pobre estatus de vitamina D3,la absorción fraccional intestinal aparente de calcio, magnesio y fosfato fue alta, siempre superior al 90%. La suplementación oral con colecalciferol a las ratas topo no mejoró la eficacia de la absorción gastrointestinal de estos minerales. No muestran la lesión típica del raquitismo: cartílagos de crecimiento hipertróficos y radiolúcidos. Varios estudios histológicos confirman los hallazgos radiológicos y se informan parámetros normales de la calidad ósea trabecular y cortical. Los titíes (monos del Nuevo Mundo) exhiben calcemias normales con niveles más elevados de 25-hidroxivitamina D3, 1α,25-dihidroxivitamina D3 y hormona paratiroidea que los monos rhesus y los seres humanos. Un tercio de un grupo de titíes alimentados con una alta ingesta de vitamina D3 (110 I/día/100 g de peso corporal) exhibió cambios osteomalácicos en sus huesos: aumento en la superficie osteoide, volumen osteoide y activa reabsorción osteoclástica. Estos hallazgos sugieren que una fracción de la población de titíes padece raquitismo dependiente de vitamina D, tipo II. Debido a mutaciones ocurridas hace millones de años, las máximas capacidades de ligamiento del VDR o los valores de la constante de disociación del complejo VDR-1α,25(OH)2D3 de las ratas topo o monos del Nuevo Mundo son muy diferentes de los verificables en receptores aislados de células humanas actuales. El mensaje de esta revisión a los médicos clínicos podría ser: varios estudios clínicos recientes indican que la normalidad de las funciones fisiológicas de un paciente es un mejor indicador de su salud que los niveles séricos de los metabolitos de la vitamina D. (AU)

Síndrome de Fanconi y raquitismo hipofosfatémico asociado al uso de tenofovir en una niña infectada con VIH / Tenofovir-associated Fanconi`s syndrome and rickets in a HIV infected girl

El tenofovir (TDF) es un inhibidor de la transcriptasa reversa análogo de nucleótidos, aunque tiene buena tolerabilidad y alta actividad antirretroviral, su efecto sobre el riñón ha sido un motivo de preocupación. Objetivo: Describir el caso de una niña infectada por VIH que presenta síntomas y hallazgos de laboratorio compatibles con un síndrome de Fanconi durante el tratamiento con TDF como parte de su terapia antirretroviral. Caso clínico: Niña infectada por el VIH-1, que después de 18 meses con el tratamiento con TDF presentó pérdida de fuerza y dolor de las extremidades inferiores con deterioro funcional. Los hallazgos de laboratorio fueron compatibles con el síndrome de Fanconi. Las radiografías mostraron fractura bilateral de cadera y muñecas. El síndrome de Fanconi se recuperó por completo cuatro meses después del cambio de terapia antirretroviral. Conclusiones: Los médicos que prescriben TDF deben estar preparados para detectar signos y síntomas indicativos de disfunción renal y considerar de inmediato el cambio del fármaco a otro antirretroviral.

Tenofovir (TDF) is an inhibitor of reverse transcriptase nucleotide analogue, although it has good tolerability and high anti-retroviral activity, its effect on the kidney has been a concern. Objective: To describe a girl infected with HIV who presented Fanconi syndrome during antiretroviral therapy with TDF. Clinical case: We describe a HIV-1-infected girl, who after 18 months treatment with TDF presented loss of strength and pain of the lower extremities with functional impairment. Laboratory findings were consistent with Fanconi syndrome. Radiographs showed bilateral hip fracture and wrists. Full recovery of Fanconi syndrome was achieved four months after changing antiretroviral therapy. Conclusions: TDF-prescribing physicians must be prepared to detect signs and symptoms of renal dysfunction and immediately consider switching to another antiviral drug.

Detection of enteric viruses in pancreas and spleen of broilers with runting-stunting syndrome (RSS) / Detecção de vírus entéricos em pâncreas e baço de frangos com a síndrome de nanismo e raquitismo (RSS)

Enteric disease is a multifactorial problem in chickens, which causes gastrointestinal alterations, elevated feed conversions and impairment. In the last years, several enteric viruses were implicated in enteric disease; case reports have shown their presence alone or in concomitant infections during outbreaks and have suggested that they might be determining factors in the aetiology of enteric disease. This study shows high detection rates of enteric viruses in the pancreas and spleen in samples from an outbreak of enteritis and malabsorption in 16 chicken flocks (n=80 broilers). Avian nephritis virus (ANV) was the most ubiquitous virus, present in 75% of the flocks followed by avian rotavirus group A (ART-A) with 68.75%, and by chicken astrovirus (CAstV) and chicken parvovirus (ChPV) in 43.75% of samples. Viruses were present in the pancreas of positive flocks at extremely high rates: 100% for ART-A, 91.7% for ANV, 100% for CAstV and 57.14% for ChPV. By contrast, only 16.7% and 57.14% of intestine samples were positive for ANV and CAstV, respectively. Avian reovirus (AReo) and avian adenovirus group 1 (FAdV-1) were not detected. These results suggest that high viral detection rates in pancreas samples may be a result of viremia during enteric disease, with subsequent damage of the exocrine pancreas, leading to runting-stunting syndrome (RSS).(AU)

A doença entérica é um problema multifatorial em galinhas que causa alterações gastrointestinais, conversão alimentar elevada e deficiência de crescimento. Nos últimos anos, os vírus entéricos foram associados à doença entérica; casos reportados mostraram a infecção de um único vírus e também infecções concomitantes durante os surtos sugerindo a presença de múltiplos fatores etiológicos nas doenças entéricas. Este estudo mostra uma alta taxa de detecção dos vírus entéricos em amostras de pâncreas e baço de um surto de enterite e má-absorção em 16 lotes de frangos (n=80 frangos). O vírus de nefrite aviária (ANV) foi o vírus mais detectado, estando presente em 75% dos lotes seguido pelo rotavírus aviário grupo A (ART-A) em 68,75% dos casos, e pelo astrovirus (CAstV) e parvovírus aviários (ChPV), ambos em 43,75% das amostras. Os vírus estavam presentes no pâncreas dos lotes positivos em percentuais elevados: 100% para ART-A e CAstV; 91,7% para ANV, e em 57,14% para ChPV. Em contraste, somente 16,7% e 57,14%, em amostras de intestino, foram positivos para ANV e CAstV, respectivamente. Reovírus aviário (AReo) e o adenovírus do grupo 1 (FAdV-1) não foram detectados. Estes resultados sugerem que os elevados percentuais de vírus detectados em amostras de pâncreas podem estar associados à viremia durante a doença entérica, com subsequente lesão no pâncreas exócrino das aves levando ao desenvolvimento da síndrome de nanismo e raquitismo.(AU)

Raquitismo e osteomalácia hipofosfatêmicos de origem genética mediados por FGF23: caracterização molecular, óssea e renal / FGF23-mediated inherited hypophosphatemic rickets: molecular characterization, bone analysis and renal evaluation

Introdução: raquitismo e osteomalácia hipofosfatêmicos de origem genética mediados por FGF23 (RQ/OM-FGF23) são caracterizados pelo aumento patológico dos níveis séricos de FGF23 com consequentes hiperfosfatúria e hipofosfatemia. A forma hereditária mais comum é a ligada ao X dominante (XLHR) ocasionada por mutações inativadoras no gene PHEX. Objetivos: identificar a etiologia molecular; avaliar a densidade mineral óssea (DMO) e a microarquitetura óssea e, determinar a prevalência de nefrocalcinose (NC), nefrolitíase (NL) e de alterações metabólicas urinárias em 47 pacientes com RQ/OM-FGF23 (16 crianças e 31 adultos). Métodos: as análises dos genes PHEX e FGF23 foram realizadas pelos métodos de Sanger e MLPA. A DMO areal (DMOa) foi avaliada por densitometria óssea (DXA), enquanto a DMO volumétrica (DMOv) e os parâmetros de microarquitetura óssea foram analisados por HR-pQCT. A NC foi classificada segundo uma escala de 0-3 (0 = ausência de NC; 3 = NC grave) pelas ultrassonografia (US) e tomografia computadorizada (TC) renais. A presença de NL foi analisada pela TC renal. Fatores de risco para NC e NL foram avaliados pela urina de 24 horas. Resultados: foram identificadas mutações no PHEX em 41 pacientes (87,2%). A avaliação óssea foi realizada em 38 pacientes com XLHR que foram comparados a controles saudáveis. Os pacientes tiveram maior DMOa em L1-L4 (p=0,03) e menor DMOa em 1/3 distal do rádio (p < 0,01). Em rádio distal, a DMOv total (Total.vBMD) e os componentes trabecular (Tb.vBMD) e cortical (Ct.vBMD) foram semelhantes entre os grupos. Na tíbia distal, os pacientes apresentaram menor Total.vBMD em relação aos controles devido ao déficit no Tb.vBMD (p < 0,01). Além do mais, ao separarmos por status metabólico, os pacientes descompensados tiveram menor Ct.vBMD em tíbia distal comparados aos controles (p=0,02). Quanto aos parâmetros estruturais, em rádio distal, os pacientes apresentaram menor número de trabéculas (Tb.N; p=0,01), maior espessura trabecular...

Background: FGF23-mediated hypophosphatemic rickets is a group of diseases characterized by a pathological increase of FGF23 serum levels, resulting in hyperphosphaturia and hypophosphatemia. In this group, the most common form of inheritance is the X-linked dominant (XLHR) caused by inactivating mutations in the PHEX gene. Aims: to identify the molecular basis; to evaluate the bone mineral density and bone microarchitecture; to determinate the prevalence of nephrocalcinosis (NC), nephrolithiasis (NL) and their related metabolic factors in 47 patients with FGF23-mediated hypophosphatemic rickets (16 children and 31 adults). Methods: PHEX and FGF23 were analyzed by conventional Sanger sequencing and MLPA. The areal BMD (aBMD) was evaluated by dual-energy x-ray absorptiometry (DXA), while the volumetric BMD (vBMD) and the bone microarchitecture were analyzed by high-resolution peripheral quantitative computed tomography (HR-pQCT). NC was investigated by renal ultrasonography (US) and computed tomography (CT) and classified using a 0-3 scale (0= no NC and 3= severe NC). The presence of NL was determined by renal CT. Risk factors for NC and NL were evaluated by 24-hour urinary samples. Results: 41 patients (87.2%) presented mutations in PHEX. The bone analysis was made in 38 XLHR patients compared to healthy controls. XLHR patients presented higher aBMD at L1-L4 (p=0.03) and lower aBMD at the distal third of the radius (p < 0.01). At the distal radius, HR-pQCT showed no differences in the vBMD neither in its trabecular (Tb.vBMD) and cortical (Ct.vBMD) components. At the distal tibia, the XLHR patients showed lower Total.vBMD (p < 0.01) compared to controls due to decreased Tb.vBMD (p < 0.01). Moreover, after XLHR patients were sorted by metabolic status, the noncompensated ones revealed lower Ct.vBMD at the distal tibia compared to their respective controls (p=0.02). Regarding to the microarchitectural parameters, at the distal radius, XLHR...

Diagnóstico diferencial del raquitismo hipocalcémico. caso clínico / Differential diagnosis in hypocalcemic rickets: a clinical case

Introducción: La hipocalcemia es un hallazgo infrecuente en los pacientes atendidos en los servicios de urgencia pediátricos. El raquitismo se puede presentar como una hipocalcemia crónica la mayoría de las veces asintomática, sin embargo, algunos pacientes presentan tetanias hipocalcémica. Objetivo: Presentar el caso clínico de una niña con raquitismo hipocalcémico, cuyo diagnóstico fue tardío. Caso clínico: Prescolar de 2 años 5 meses con alteración en la marcha, mal incremento ponderal, espasmos musculares y signos de raquitismo activo. Los exámenes revelaron hipocalcemia severa, normofosfemia, fosfatasa alcalina y PTH elevada y niveles normales de 25 hidroxivitamina D. Se manejó con calcio y calcitriol, y se diagnosticó raquitismo vitamina D dependiente tipo I. Conclusión: Los síntomas y signos clásicos de raquitismo, así como la hipocalcemia, deben hacernos plantear hoy en día el diagnóstico de raquitismo. Un mejor conocimiento de esta patología permitirá evitar el retraso en el diagnóstico y un tratamiento más oportuno.

Introduction: Hypocalcemia is rare in patients attending pediatric emergency services. Rickets can present as a chronic hypocalcemia often asymptomatic, poor growth rate, psychomotor delay and bone abnormalities, but some patients may present tetanic seizures. Although its incidence has decreased, a resurgence of rickets has been described. Objective: To present a case of a child with hypocalcemic rickets, whose diagnosis was delayed. Case report: Preschool of 2,4 years old with gait disturbance, poor growth rate, muscle spams and signs of active rickets. Laboratory results showed hypocalcemia, normophosphemia, alkaline phosphatase, high PTH and normal 25-hydroxyvitamin D levels. She received treatment with calcium and calcitriol and had a good response; Vitamin D dependent rickets type I was diagnosed. Conclusion: Classics signs and symptoms of rickets, as hypocalcemic manifestations, should lead us today to diagnose rickets. Better knowledge of this disease will avoid retarded diagnosis and give a suitable treatment.

Fracturas en una mujer con mialgias difusas e hipocaliemias graves / Fractures in a woman with severe diffuse myalgias and hypokalemia

Resumen El déficit en la mineralización ósea caracteriza al raquitismo y a la osteomalacia, las cuales pueden ser secundarias a deficiencias de calcio o de vitamina D principalmente. La osteomalacia genera síntomas inespecíficos e insidiosos, usualmente minimizados, y puede confundirse con otras condiciones médicas. La densitometría ósea no diferencia entre osteoporosis y osteomalacia, por lo cual corresponde al clínico hacer una evaluación juiciosa de los síntomas, factores de riesgo, antecedentes, alteraciones de laboratorio y hallazgos radiológicos para tratar de descartar la presencia aislada o simultánea de osteomalacia. La exclusión de osteomalacia tiene importantes repercusiones terapéuticas y pronósticas. Presentamos el caso de una paciente con osteomalacia con varias fracturas espontáneas, pseudofracturas de Looser-Milkman, deformidades angulares en rodillas, mialgias difusas y antecedente de acidosis tubular renal, hipocaliemias graves y sordera neurosensorial, la cual venía rotulada y tratada erróneamente como osteoporosis. (Acta Med Colomb 2013; 38: 255-257).

Abstract The deficit in bone mineralization characterizes rickets and osteomalacia, which may be secondary to deficiencies of calcium or mainly of vitamin D. Osteomalacia generates unspecific and insidious symptoms, usually minimized , and can be confused with other medical conditions. Bone densitometry does not differentiate between osteoporosis and osteomalacia, so it is up to the clinician to make a wise assessment of symptoms, risk factors, history, laboratory abnormalities and radiographic findings to try to rule out the presence of isolated or simultaneous osteomalacia. The exclusion of osteomalacia has important therapeutic and prognostic implications. We report the case of a patient with osteomalacia with multiple spontaneous fractures, Looser-Milkman pseudo-fractures, angular deformities in knees, diffuse myalgias, and history of renal tubular acidosis, severe hipokalemias and sensorineural deafness, which had been wrongly labeled and treated as osteoporosis. (Acta Med Colomb 2013; 38: 255-257).

Vitamin D deficiency rickets in infants presenting with hypocalcaemic convulsions / Raquitismo por deficiencia de vitamina D en lactantes que presentan convulsiones por hipocalcemia

AIM: Hypocalcaemia evaluation of the clinical, biochemical and radiological features of 91 infants with rickets who presented as hypocalcaemic convulsions. SUBJECTS AND METHODS: Ninety-one hypocalcaemic infants who were brought to hospital with convulsion and diag-nosed with rickets related to vitamin D deficiency according to their clinical, biochemical and radio-logical features were retrospectively reviewed. RESULTS: Mean values of the laboratory data were as follows: calcium 5.55 ± 0.79 mg/dL, phosphorus 4.77 ± 1.66 mg/dL, alkaline phosphatase 1525.5 ± 925.4 U/L and parathormone 256.8 ± 158.3 pg/mL. Serum 25-OH vitamin D levels were below normal (< 20 ng/mL) in 37 infants. CONCLUSION: Vitamin D deficiency should be considered in infants presenting with hypocalcaemia. To avoid complications such as convulsions, clinicians should give vitamin D supplementation to such infants.

OBJETIVO: Evaluación hipocalcémica de los aspectos clínicos, bioquímicos y radiológicos de 91 lactantes con raquitismo, que presentaron convulsiones por hipocalcemia. PACIENTES Y MÉTODOS: Noventa y un lactantes hipocalcémicos llevados al hospital con convulsiones y a quienes se les diagnosticó raquitismo asociado a la deficiencia de vitamina D de acuerdo con sus características, bioquímicas y radiológicas, fueron revisados retrospectivamente. RESULTADOS: Los valores medios de los datos de laboratorio fueron los siguientes: calcio 5.55 ± 0.79 mg/dL, fósforo 4.77 ± 1.66 mg/dL, fosfatasa alcalina 1525.5 ± 925.4 U/L, y paratohormona 256.8± 158.3 pg/mL. Los niveles séricos de la vitamina 25 (OH) D estuvieron por debajo de lo normal en 37 lactantes (< 20 ng/mL). CONCLUSIÓN: La deficiencia de vitamina D debe considerarse en los infantes que se presentan con hipocalcemia. A fin de evitar complicaciones tales como convulsiones, se les debe dar suplementos de vitamina D.

Una causa infrecuente de convulsión hipocalcémica: raquitismo congénito. Caso clínico / An uncommon cause of hypocalcemic convulsion: congenital rickets. Case report

La deficiencia de vitamina D y el raquitismo son problemas de salud importantes en los países en desarrollo. El raquitismo congénito es una forma infrecuente de raquitismo. La deficiencia materna de vitamina D es el factor de riesgo más importante para la deficiencia de vitamina D y el raquitismo en los recién nacidos y lactantes. Presentamos el caso de un niño de 2 meses de edad, con convulsiones durante su hospitalización por neumonía. Se diagnosticó raquitismo congénito asociado a deficiencia materna de vitamina D.

Vitamin D deficiency and rickets are major health problems in developing countries. Congenital rickets is a rare form of rickets. Maternal vitamin D deficiency is the most important risk factor for vitamin D deficiency and rickets in newborns and early infancy. In this report, we presented a two-monthold infant with seizures while hospitalized for pulmonary infection. Finally, congenital rickets due to maternal vitamin D deficiency was diagnosed.