Vitamin D Toxicity-A Clinical Perspective.

Area of Science:

• Endocrinology
• Nutritional Science
• Toxicology

Background:

• Vitamin D toxicity (VDT), also known as hypervitaminosis D, is a serious condition resulting from excessive vitamin D intake.
• Symptoms include confusion, vomiting, abdominal pain, polyuria, polydipsia, and dehydration, often linked to severe hypercalcemia.
• VDT can stem from exogenous sources (overdosing on supplements) or endogenous factors (metabolic pathway dysfunctions or specific diseases).

Purpose of the Study:

• To elucidate the causes, manifestations, and diagnostic hallmarks of Vitamin D toxicity.
• To highlight the potential risks associated with increased public awareness and self-administration of vitamin D supplements.
• To discuss the mechanisms underlying VDT, including metabolic pathway disruptions and hypersensitivity.

Main Methods:

• Review of clinical symptoms and laboratory findings associated with VDT.
• Analysis of serum 25-hydroxyvitamin D [25(OH)D] concentrations as a diagnostic marker.
• Examination of endogenous causes, including granulomatous disorders, lymphomas, and congenital conditions.

Main Results:

• Serum 25(OH)D concentrations exceeding 150 ng/ml are indicative of VDT from overdosing.
• Asymptomatic hypercalcemia can occur even with recommended vitamin D doses in hypersensitive individuals.
• Dysregulated vitamin D metabolism, including altered enzyme activity and receptor function, contributes to VDT.

Conclusions:

• VDT, though rare, poses significant health risks if not promptly diagnosed and managed.
• Increased vitamin D awareness may lead to higher incidence of VDT due to inappropriate self-supplementation.
• Understanding the various forms and mechanisms of VDT is essential for clinical practice and public health guidance.