Differential Diagnosis for Loss of Appetite and Low Vitamin D

• Single Most Likely Diagnosis
  • Depression: Loss of appetite and low vitamin D can be associated with depression, as individuals with depression may experience changes in appetite and have limited sun exposure, leading to vitamin D deficiency.
• Other Likely Diagnoses
  • Gastrointestinal disorders (e.g., celiac disease, Crohn's disease): These conditions can lead to malabsorption of nutrients, including vitamin D, and cause a decrease in appetite.
  • Chronic kidney disease: Impaired kidney function can result in low vitamin D levels, and loss of appetite is a common symptom in advanced stages.
  • Hypothyroidism: This condition can cause changes in appetite and metabolism, leading to weight loss and low vitamin D levels.
• Do Not Miss Diagnoses
  • Malignancy (e.g., pancreatic cancer): Certain types of cancer can cause loss of appetite and low vitamin D levels due to malabsorption or tumor effects.
  • Sarcoidosis: This autoimmune disease can lead to vitamin D deficiency and loss of appetite due to granulomatous inflammation.
  • Osteomalacia: A condition characterized by softening of the bones due to severe vitamin D deficiency, which can cause loss of appetite and other systemic symptoms.
• Rare Diagnoses
  • Whipple's disease: A rare bacterial infection that can cause malabsorption, leading to low vitamin D levels and loss of appetite.
  • Gaucher's disease: A genetic disorder that can result in vitamin D deficiency and loss of appetite due to spleen and liver involvement.
  • Pernicious anemia: A condition caused by vitamin B12 deficiency, which can also lead to low vitamin D levels and loss of appetite due to gastrointestinal symptoms.