Resistant Hypertension and Renal Injury Related to High-Dosage Vitamin D Intake: A Case Report.

Abstract

The use of vitamin D in outpatient care has increased exponentially in recent years. The replacement for vitamin D deficiency (lower than 30nmol/l) for enhanced bone health is consensual in the literature. The real benefits of supplementing vitamin D for extra-skeletal or articular disease are unclear. Although there is no evidence, an off-label use of massive doses for joint disease treatment is observed, with an obvious risk of toxicity. Misuse by iatrogenic or self-medication can lead to toxicity, which may occur with plasma concentrations above 150ng/ml. There is a report of a 1600% elevation in the exposition to toxicity in the past decade in the United States. Vitamin D toxicity features are often related to hypercalcemia, with neuropsychiatric, gastrointestinal, cardiovascular, and renal findings. We describe a case of a 57-year-old man who presented with resistant hypertension and acute kidney injury. He had edema, flushing, headache, and recent elevation of a former well-controlled hypertension. Laboratory findings were high creatinine levels, proteinuria, and a vitamin D dosage of 156ng/ml. He had an ankylosing spondylitis diagnosis and tried to relieve its symptoms by using vitamin D, 10000ui, once daily in the last six months, prescribed by a nutritional specialist. The blood pressure levels, and glomerular filtration rate were near average three months after suspension, but vitamin D levels remained high (>100ng/ml) for 12 months. Clinicians and the population should be aware of these risks.