Hypercalcemia and renal function impairment associated with vitamin D toxicity: case report / Hipercalcemia e prejuízo de função renal associados à intoxicação por vitamina D: relato de caso

Abstract Nowadays vitamin D (25-OHD) deficiency is supposed to be a global epidemic condition. Expectedly, vitamin D measurement and intake exponentially increased in Brazil in this decade. Although the benefit of vitamin D to general health is still in debate, its indiscriminate use potentially may lead to enhance the incidence of vitamin D intoxication, which is considered a rare disorder. We report a case of a 70 year old diabetic male with chronic renal disease (blood creatinine of 1.6 mg/dL) who progressed suddenly to acute kidney injury (blood creatinine of 5.7 mg/dL) associated with hypercalcemia and high blood levels of vitamin D. Vitamin D and calcitriol were discontinued and hypercalcemia was managed by hydration followed by furosemide. Thereafter, disodium pamidronate was administered and the patient did not undergo on dialysis. It took approximately 14 months to normalize 25-OHD levels and blood creatinine returned to basal levels only after 24 months. The indicated labeling dosage was 2000 IU, but most likely the vitamin D manipulated preparation was higher as the vitamin D blood levels were very high. Although rare, vitamin D intoxication is becoming more frequent as the patients use frequently manipulated preparations that could be subject to errors in the manufacturing and labeling of the tablets or capsules. The present report alerts to the potential increase in the incidence of severe vitamin D intoxication due to the frequent use of this secosteroid as a nutritional supplement. At the same time, it is necessary to improve regulation on the nutrient supplement market.

Resumo Atualmente, muitos brasileiros têm utilizado vitamina D (25-OHD) como suplemento vitamínico para prevenção de diversas doenças crônicas, apesar da falta de dados científicos consistentes sobre o papel deste secosteroide na prevenção de doenças que não as do metabolismo mineral. A intoxicação por vitamina D é rara, mas devido ao seu uso indiscriminado tem ocorrido com maior frequência. Nesse relato, um homem diabético de 70 anos de idade com doença renal crônica (creatinina sérica de 1,6 mg/dL) passou a fazer uso de colecalciferol e calcitriol para recomposição dos níveis de 25-OHD, que eram de 16 ng/mL. O mesmo desenvolveu quadro de lesão renal aguda (creatinina = 5,7 mg/dL), após 45 dias. Este processo emergiu em paralelo ao surgimento de hipercalcemia e níveis circulantes elevados de vitamina D. Foram suspensas a administração de vitamina D e calcitriol, a hipercalcemia foi tratada com hidratação endovenosa, seguida de diurético de alça e posteriormente pamidronato. O paciente, que havia sido encaminhado para diálise, não necessitou desse tratamento. Os níveis de 25-OHD voltaram ao normal 14 meses após a sua suspensão, e os níveis de creatinina voltaram aos patamares anteriores 24 meses após esse evento. A dose prescrita de vitamina D correspondeu a 2000 UI/dia, a qual não é considerada inadequada segundo recomendações atuais. Existe, no entanto, na literatura controvérsia quanto à sensibilidade individual à vitamina D. Não pode ser descartado o uso inapropriado pelo paciente e nem eventual erro de manipulação. Embora raro, o quadro de intoxicação por vitamina D é grave e potencialmente pode levar a complicações clínicas irreversíveis.

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