Vitamin A toxicity and hypercalcemia

Area of Science:

• Endocrinology
• Toxicology

Background:

• Hypercalcemia is a common clinical finding with diverse etiologies.
• Vitamin A toxicity (hypervitaminosis A) is typically associated with neurological and dermatological symptoms.
• A rare association between vitamin A toxicity and hypercalcemia has been suggested but is not well-documented.

Observation:

• A patient presented with hypercalcemia and a history of excessive chronic vitamin A intake.
• Clinical manifestations included profound weight loss, psychiatric disturbance, alopecia, erosive dermatitis, and liver disease.
• Elevated serum vitamin A levels, specifically retinyl esters, confirmed hypervitaminosis A.

Findings:

• The patient's hypercalcemia was not attributable to other common causes.
• The clinical and biochemical profile strongly indicated vitamin A toxicity as the cause of hypercalcemia.
• Vitamin A's known effects on bone metabolism provide a plausible mechanism.

Implications:

• Vitamin A toxicity should be considered in the differential diagnosis of hypercalcemia, especially with a history of excessive intake.
• This case highlights a rare but significant complication of chronic vitamin A abuse.
• Further research may elucidate the precise mechanisms linking vitamin A to bone calcium regulation.