Nephrology
Fazal-I-Akbar Danish in Essential Lists of Differential Diagnoses for MRCP with diagnostic hints, 2017
Renal tubular acidosis (RTA) type 1 (distal):1 Inherited.2 Acquired: a Liver pathology (chronic active hepatitis; PBC).b Renal pathology (obstructive nephropathy).c Vitamin D intoxication.d Drugs (tetracycline).
Fat-Soluble Vitamins
Luke R. Bucci in Nutrition Applied to Injury Rehabilitation and Sports Medicine, 2020
Vitamin D is the second-most toxic vitamin, behind retinoids. Excess intakes of cholecalciferol (over 250 μg or 10,000 IU daily) cause hypercalcemia.500 However, toxicity symptoms are not seen until consumption of over 50,000 IU/d for long time periods (several months).499 Clinical symptoms of weakness, nausea, anorexia, headaches, abdominal pains, cramps, and diarrhea are associated with vitamin D toxicity.500 Osteopenia and soft tissue calcifications (including arteries) become apparent.499 Excess vitamin D metabolites decrease collagen synthesis and cross-linking.93,94 Thus, excess vitamin D may lead to increased susceptibility of musculoskeletal injuries for athletes. For these reasons, and the greatly increased potency of 1,25OHD, vitamin D metabolites are prescription items. Thus, excess vitamin D intake is harmful when continued.
Micronutrients
Chuong Pham-Huy, Bruno Pham Huy in Food and Lifestyle in Health and Disease, 2022
Inversely, high intake of vitamin D mostly by supplementation can cause toxicity to the body because vitamin D is fat-soluble and can be stocked long-term in fatty tissues and organs. Vitamin D toxicity can cause non-specific symptoms such as anorexia, weight loss, polyuria, and heart arrhythmias. More seriously, it can also raise blood levels of calcium which leads to vascular and tissue calcification, with subsequent damage to the heart, blood vessels, and kidneys (64). A study observed that the use of supplements of both calcium (1,000 mg/day) and vitamin D (400 IU) by postmenopausal women was associated with a 17% increase in the risk of kidney stones over 7 years (64). A 25-OH-D concentration in serum consistently >500 nmol/L (>200 ng/mL) is considered to be potentially toxic (64). The use of vitamin D supplements for therapeutics must be done by a professional healthcare agent. Intakes of food rich in vitamin D are safer than high intakes of dietary supplements containing vitamin D.
When and How to Diagnose and Treat Vitamin D Deficiency in Adults: A Practical and Clinical Update
Published in Journal of Dietary Supplements, 2020
Antoine Aoun, Jessica Maalouf, Myriam Fahed, Flora El Jabbour
Vitamin D toxicity should not be diagnosed solely on the basis of an elevated 25(OH)D level; it should rather be recognized as a clinical syndrome of both hypervitaminosis D and hypercalcemia, in which hyperphosphatemia and hypercalciuria also commonly occur. Patients with vitamin D toxicity can present with clinical symptoms (e.g., headache, metallic taste, nausea, and vomiting) and complications of hypercalcemia (e.g., dehydration, constipation, pancreatitis, and heart arrhythmias) and hypercalciuria (e.g., polyuria and kidney stones) (National Institute of Health 2016). While hypervitaminosis D in the absence of hypercalcemia may prompt further investigation to evaluate the etiology of increased vitamin D levels, it is not a medical emergency as is hypercalcemia.
Vitamin D: sources, physiological role, biokinetics, deficiency, therapeutic use, toxicity, and overview of analytical methods for detection of vitamin D and its metabolites
Published in Critical Reviews in Clinical Laboratory Sciences, 2022
Jiří Janoušek, Veronika Pilařová, Kateřina Macáková, Anderson Nomura, Jéssica Veiga-Matos, Diana Dias da Silva, Fernando Remião, Luciano Saso, Kateřina Malá-Ládová, Josef Malý, Lucie Nováková, Přemysl Mladěnka
Since the number of scientific reports on the potential benefits of vitamin D on different diseases is large and continues to increase, fortified food and vitamin D supplements have become easily obtainable over-the-counter in pharmacies, supermarkets, and online stores [296], and this market has been growing all over the world [301]. As such, in addition to iatrogenic factors, the causes of vitamin D overdose and subsequent toxicity are mainly associated with self-medication, accidental incorrect doses (for instance due to prescribing errors), or the use of unlicensed and/or poorly standardized products [289,295]. The latter was associated with the urgent need for vitamin D products to be certified by highly harmonized analytical methodologies [302]. Several validated methods and standardized protocols have been provided by international authorities, including the United States Pharmacopeia in the Vitamin D Assay Monography (581) [303] and European Standard approved by the European Committee on Standardization [304], to increase the quality of dietary supplements. These guidelines summarize analytical procedure conditions for various formulations, which are described in detail with acceptable tolerance limits [305]. Nevertheless, it should be emphasized, that the regulation and quality control of dietary supplements differ in individual countries based on the current law and recommendations, thus in some cases, there is a lack of dietary supplement control that can lead to poor quality products. Indeed, two adult cases of chronic vitamin D intoxication caused by manufacturing errors have been reported [289,295]. In both cases, the real vitamin D level was 1000-fold higher than the daily dose level declared by the manufacturer, which points to a failure in quality control.
Hypervitaminosis D without toxicity
Published in Baylor University Medical Center Proceedings, 2020
Jasmin Rahesh, Victoria Chu, Alan N. Peiris
Despite marked elevation of vitamin D levels, our patient did not show any evidence of clinical or biochemical toxicity. To our knowledge, this is only the second such case reported.4 Vitamin D toxicity is usually related to excessive ingestion and is rarely a result of physician prescriptions. Vitamin D toxicity is usually seen with a 25(OH)D level >150 ng/mL.3 In vitamin D toxicity, common clinical manifestations include severe hypercalcemia, confusion, apathy, recurrent vomiting, abdominal pain, polyuria, polydipsia, and dehydration.5