Forget the phosphorus: A case of hypervitaminosis D-induced symptomatic hypercalcemia

Area of Science:

• Endocrinology
• Internal Medicine
• Clinical Case Reports

Background:

• Hypercalcemia is a common electrolyte disturbance with established diagnostic pathways.
• Hypervitaminosis D is a rare but increasingly reported cause of hypercalcemia.
• Vitamin D supplementation is widely used, leading to more frequent cases of toxicity.

Observation:

• A patient presented with altered mental status attributed to hypercalcemia.
• The diagnosis of hypervitaminosis D was delayed.
• An incorrect assumption about phosphatemia levels led to unnecessary invasive investigations.

Findings:

• The case highlights hypervitaminosis D as a cause of altered mental status.
• Delayed diagnosis resulted from a misconception regarding phosphatemia in hypervitaminosis D.
• Invasive testing was performed due to diagnostic delays.

Implications:

• This case underscores the importance of considering hypervitaminosis D in hypercalcemia evaluations.
• Accurate assessment of vitamin D and calcium levels is critical for correct diagnosis.
• Avoiding assumptions about associated electrolyte abnormalities can prevent unnecessary procedures.