Differential Diagnosis for Progressive Weakness and Hematuria

Given the symptoms of progressive weakness and hematuria, along with the patient's history of taking high doses of vitamin D (7000 IU daily for years), the following differential diagnoses are considered:

• Single Most Likely Diagnosis

  • Vitamin D Toxicity: The patient's long-term intake of high doses of vitamin D increases the risk of vitamin D toxicity, which can lead to hypercalcemia. Hypercalcemia can cause a range of symptoms including muscle weakness, renal impairment, and potentially hematuria due to kidney stone formation or nephrocalcinosis.

• Other Likely Diagnoses

  • Nephrolithiasis (Kidney Stones): High levels of vitamin D can increase calcium absorption, leading to an increased risk of developing kidney stones, which can cause hematuria and potentially contribute to progressive weakness if associated with chronic pain or infection.
  • Chronic Kidney Disease (CKD): Prolonged hypercalcemia from vitamin D toxicity can lead to CKD, characterized by progressive weakness among other symptoms, and hematuria can be a sign of kidney damage.
  • Hyperparathyroidism: Although less directly related to vitamin D intake, hyperparathyroidism can cause hypercalcemia, leading to similar symptoms. However, it's less likely given the context of high vitamin D intake.

• Do Not Miss Diagnoses

  • Multiple Myeloma: A malignancy that can cause hypercalcemia (leading to weakness) and renal impairment (leading to hematuria). Although less likely, missing this diagnosis could be fatal.
  • Sarcoidosis: Can cause hypercalcemia due to increased vitamin D conversion to its active form, leading to symptoms similar to those described. It's crucial not to miss this diagnosis due to its potential for serious complications.

• Rare Diagnoses

  • Familial Hypocalciuric Hypercalcemia (FHH): A rare genetic disorder that affects calcium metabolism, potentially leading to hypercalcemia and its associated symptoms. However, the direct link to high vitamin D intake and the specific symptoms mentioned makes this a less likely consideration.
  • Williams Syndrome: A genetic disorder that can include hypercalcemia among its features, but it's very rare and typically diagnosed in childhood, making it an unlikely diagnosis in this context.