Hypervitaminosis A: A Rare Cause of Hypercalcemia

Introduction: Hypercalcemia is a rather common clinical problem and a majority of cases are found to be secondary to primary hyperparathyroidism and malignancy. A rare cause of hypercalcemia is associated with high levels of vitamin A and thought to be secondary to the effect of vitamin A on bone to stimulate osteoclastic resorption or inhibit osteoblastic formation. Clinical Case: A 54 year-old male with a past medical history of CKD stage 3 secondary to medullary sponge kidney presented for hypercalcemia. He complained of chronic constipation, joint pain, mood changes and recurrent kidney stones. Reported multivitamin use (including 1000mcg of vitamin A) for years but was discontinued one year prior to visit. Lab work showed calcium of 11.5 mg/dL (8.7–10.2mg/dL), albumin 4.9 g/dL (3.8–4.9g/dL), elevated 24h urine calcium, eGFR 40 mL/min/1.73, parathyroid hormone 5 pg/mL (15-65pg/mL,) normal 1,25-OH vit D and 25-OH vit D, PTHrP <2.0 pmol/L, serum protein electrophoresis unremarkable. His vitamin A level was elevated to 103 ug/dL (20.1–62.0ug/dL). CT chest showed no findings concerning for sarcoidosis. Bone density scan showed normal bone mineral density. Patient diagnosed with hypercalcemia secondary to elevated vitamin A levels. Current limited literature shows stopping the vitamin A supplement will normalize vitamin A levels and correct the hypercalcemia. This patient had discontinued his multivitamin 1 year prior and vitamin A remained elevated, thought to be due to his poor kidney function. Treatment was targeted at improving his hypercalcemia and reducing his symptoms. He was prescribed a one-week course of prednisone 40 mg daily. His calcium level improved to 10.5 mg/dL. Prednisone was reduced to 20 mg daily with normalization of calcium to 10.3 mg/dL (8.7–10.2mg/dL). Conclusion: Hypercalcemia is a rare but known complication of vitamin D toxicity. The liver, kidney and adrenal glands store vitamin A and it is excreted in the urine. Liver and kidney disease pose higher risk of vitamin A toxicity. We present a unique case of Hypercalcemia secondary to elevated vitamin A levels in a patient with moderate chronic kidney disease who was not taking excessive amounts of vitamin A and whose calcium and vitamin A did not normalize once vitamin A supplements were discontinued. The CKD 3 may have reduced vitamin A clearance and increased its toxicity. Hypercalcemia is not the only concern regarding vitamin A toxicity, the increasing use of dietary supplements and over the counter medications may pose significant risks for osteoporosis and bone fractures. A high clinical suspicion and thorough workup to exclude other causes of hypercalcemia is warranted to diagnose hypervitaminosis A as the etiology. Steroids can reduce gastrointestinal absorption of calcium, however, its role in vitamin A toxicity remains unclear. Further research is needed to investigate the appropriate treatment for these patients.

CFTR Modulator Therapy with Lumacaftor/Ivacaftor Alters Plasma Concentrations of Lipid-Soluble Vitamins A and E in Patients with Cystic Fibrosis

Rationale: Cystic fibrosis (CF), caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, leads to impaired pancreatic function and therefore reduced intestinal absorption of lipids and fat-soluble vitamins especially in patients with CF developing pancreatic insufficiency (PI). Previous studies showed that CFTR modulator therapy with lumacaftor-ivacaftor (LUM/IVA) in Phe508del-homozygous patients with CF results in improvement of pulmonary disease and thriving. However, the effects of LUM/IVA on plasma concentration of the lipid soluble vitamins A and E remain unknown. Objectives: To investigate the course of plasma vitamin A and E in patients with CF under LUM/IVA therapy. Methods: Data from annual follow-up examinations of patients with CF were obtained to assess clinical outcomes including pulmonary function status, body mass index (BMI), and clinical chemistry as well as fat-soluble vitamins in Phe508del-homozygous CF patients before initiation and during LUM/IVA therapy. Results: Patients with CF receiving LUM/IVA improved substantially, including improvement in pulmonary inflammation, associated with a decrease in blood immunoglobulin G (IgG) from 9.4 to 8.2 g/L after two years (p < 0.001). During the same time, plasma vitamin A increased significantly from 1.2 to 1.6 µmol/L (p < 0.05), however, levels above the upper limit of normal were not detected in any of the patients. In contrast, plasma vitamin E as vitamin E/cholesterol ratio decreased moderately over the same time from 6.2 to 5.5 µmol/L (p < 0.01). Conclusions: CFTR modulator therapy with LUM/IVA alters concentrations of vitamins A and vitamin E in plasma. The increase of vitamin A must be monitored critically to avoid hypervitaminosis A in patients with CF.

Adequate vitamin A liver stores estimated by the modified relative dose response test are positively associated with breastfeeding but not vitamin A supplementation in Senegalese urban children 9–23 months old: A comparative cross-sectional study

Vitamin A supplementation (VAS) in 6-59-month-old children is recommended but its sustainability is currently questioned. In Senegal, available data suggest that VAS should be maintained, but geographic and age-related specificities need to be addressed to better implement and target VAS programming. The objective of this comparative cross-sectional study, conducted in urban settings of Dakar, was to compare the vitamin A liver stores (VALS) assessed using the modified-relative dose response (MRDR) test between supplemented and non-supplemented 9–23 month-old children and to study their relationship with VAS. The supplemented group (n = 119) received VAS (either 100 000 UI or 200 000 UI) 2 to 6 months before evaluation while the non-supplemented group (n = 110) had not received VAS during the past 6 months. In addition to MRDR, serum retinol concentrations (SR), and biomarkers of subclinical inflammation were measured. Children’s health-related data and feeding patterns were collected. Mean MRDR values (VAS: 0.030 ± 0.017, non-VAS: 0.028 ± 0.016, P = 0.389) and inflammation-adjusted SR (VAS: 1.34 ± 0.37, non-VAS: 1.3 ± 0.35, P = 0.515) of children were adequate. Low prevalence of VALS (VAS: 5.2%, non-VAS: 5.4%) and inflammation-adjusted VAD (VAS: 2.6%, non-VAS: 0.9%) were detected despite high presence of infections and inflammation. Children were mostly still being breastfed (VAS: 85.7%, non-VAS: 77.3%) and complementary feeding indicators were similar in both groups. Only breastfeeding was associated with VALS and was found to reduce by 76% at least, the odds of VAD (adjusted OR = 0.24, 95% CI: 0.07–0.8, P = 0.020). Based on MRDR values, VAS was not related to improved VALS and SR as well as VAD reduction among these children with adequate VALS. Reinforcing breastfeeding advocacy and morbidity prevention/control are essential in this setting. Scaling-back VAS in this subpopulation should be examined regarding the risk of hypervitaminosis A after an evaluation of dietary vitamin A intake sufficiency and a more quantitative assessment of VALS.

CT and MRI characteristics of presumptive hypervitaminosis A in a cat

Case summary A rescued stray cat with an unknown history was examined for non-ambulatory paraparesis in the hindlimbs. Survey radiographs revealed typical findings of hypervitaminosis A, characterised by vertebral exostoses and extensive osteophytes, mainly in the cervicothoracic spine. CT findings were consistent with the radiographic findings, and CT-based volume rendering and virtual endoscopy into the vertebral canal were created for three-dimensional visualisation of the lesion. MRI revealed a focal and mild dilation of the central canal of the spinal cord. Although the clinical diagnosis of hypervitaminosis A is based on an unusual dietary history and characteristic radiographic findings, the history of this cat was unknown and serum concentrations of vitamin A were unremarkable, when measured >1 month after rescue. However, other possible differential diagnoses were thought to be unlikely and clinical signs never worsened, and thus, hypervitaminosis A was presumed. Relevance and novel information To our knowledge, this is the first report to present the CT and MRI characteristics of a cat with suspected hypervitaminosis A.

Multiple Vaccinations and the Enigma of Vaccine Injury

A growing number of vaccines are administered at the same time or in close succession, increasing the complexity of assessing vaccine safety. Individual vaccines are assumed to have no other effect than protection against the targeted pathogen, but vaccines also have nonspecific and interactive effects, the outcomes of which can be beneficial or harmful. To date, no controlled trials and very few observational studies have determined the impact of vaccination schedules on overall health. The balance of the risks and benefits from mass vaccination therefore remains uncertain. Recent studies worryingly suggest links between multiple vaccinations and increased risks of diverse multisystem health problems, including allergies, infections, and neuropsychiatric or neurodevelopmental disorders. Here, we propose that, in susceptible persons, multiple vaccinations activate the retinoid cascade and trigger apoptotic hepatitis, leading to cholestatic liver dysfunction, in which stored vitamin A compounds (retinyl esters and retinoic acid) enter the circulation in toxic concentrations; this induces endogenous forms of hypervitaminosis A, with the severity of adverse outcomes being directly proportional to the concentration of circulating retinoids. In very low concentrations, vitamin A and its major metabolite retinoic acid contribute to immune function and to the process of immunization, whereas excess vitamin A increases the risk of adverse events, including common “side-effects” as well as chronic adverse outcomes. The increasing rates of allergy, ear infections, and neurodevelopmental disorders (NDDs) in countries with high rates of vaccination could be related to mass vaccination and to its impact on liver function and vitamin A metabolism, collectively representing endogenous manifestations of hypervitaminosis A. Further studies of health outcomes in vaccinated and unvaccinated groups are urgently needed, to increase understanding of the pathophysiology and treatment of vaccine injury, to identify the risk factors and screen for vaccine injury, to inform public health policy on potential hazards related to vaccination schedules, and to optimize the safety and benefits of vaccines.

Hypercalcemia from hypervitaminosis A in a child with autism

ObjectivesVitamin A is essential for normal cellular physiology and is often taken as a dietary supplement. Hypervitaminosis A can lead to hypercalcemia by increasing osteoclasts and subsequent bone resporption. Dietary supplements including vitamin A are new popular treatment stategies for autism.Case presentationWe report a five-year old boy with autism spectrum disorder presenting with severe abdominal pain and bilateral lower extremity pain, who was found to have persistent hypercalcemia due to hypervitaminosis A. The patient ingested over 700 times the recommended intake of Vitamin A per day for age. Retention of vitamin A in the liver and adipose tissue causes toxic levels of retinoids and hypercalcemia.ConclusionsAcute treatment included intravenous rehydration, furosemide, and calcitonin. Pamidronate was the definitive treatment for hypercalcemia from hypervitaminosis A due to its osteoclast inhibition and long biologic half-life. Parents should be counseled on risks of toxicity and absence of evidence showing benefits of vitamin A therapy for autism.