II. Pathophysiology

  1. Excessive Vitamin D manifests as Hypercalcemia
    1. Risk of Nephrolithiasis, soft tissue calcification, Renal Injury, cardiovascular injury
  2. Toxicity requires chronic ingestions of large amounts of Vitamin D
    1. Vitamin D has been subject of dubious claims such as Covid19 prevention (no evidence of benefit, risk of harm)
    2. High Vitamin D concentrations have been used as a rodenticide
  3. Toxic ingestion Levels
    1. Acute (ingestion >100 fold higher than RDA)
      1. Toddler: >2.5 million units
      2. Adult: >4.0 million units
    2. Chronic
      1. Child: >2000 units/day
      2. Adult: >75,000 units/day

III. Risk Factors

  1. See Hypercalcemia
  2. Primary Hyperparathyroidism
  3. Sarcoidosis or other Granulomatous conditions
  4. Cancers associated with Hypercalcemia

IV. Symptoms

  1. See Hypercalcemia
  2. Gastrointestinal
    1. Nausea or Vomiting
    2. Abdominal cramps
  3. Cardiopulmonary
    1. Hypertension
    2. Arrhythmias
    3. Prolonged QRS
    4. Short QTc
  4. Neurologic
    1. Dizziness
    2. Headaches
    3. Irritability
    4. Fatigue
    5. Seizures
  5. Metabolic
    1. Hypercalcemia
    2. Renal Failure

V. Labs

  1. See Unknown Ingestion
  2. Electrolytes
    1. Including Creatinine and eGFR, Serum Calcium and Serum Phosphorus
  3. Vitamin D (25-HydroxyVitamin D)
    1. May be elevated >80-100 ng/ml
  4. Urinalysis

VI. Diagnostics

VII. Management

  1. See Hypercalcemia
  2. See Unknown Ingestion
  3. Consider Activated Charcoal for ingestion within prior hour and controlled airway
    1. Indicated for large ingestion (>100 times RDA, 17 rodenticide pellets)
  4. Intravenous Fluids and intravenous Furosemide
    1. Forced diuresis
  5. Manage Seizures
    1. Benzodiazepines are primary agents
    2. See Status Epilepticus
  6. Severe, refractory Hypercalcemia
    1. Consider Hemodialysis (with Calcium-free dialysate)
    2. Consider Prednisone
    3. Consider Bisphosphonates
  7. Disposition
    1. Minor ingestions may be monitored at home
    2. Acute Overdose
      1. Monitor for 4 to 6 hours after ingestion
    3. Severe Hypercalcemia or neurologic effects
      1. Hospital monitoring

VIII. References

  1. Tomaszeski (2022) Crit Dec Emerg Med 36(1): 28

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