Get a blood test for 25-hydroxy vitamin D [25(OH)D]
Ask a healthcare professional to interpret the result
Review symptoms such as fatigue, bone pain, muscle weakness, or frequent fractures
Check for risk factors such as limited sun exposure, darker skin, older age, obesity, or malabsorption
Consider testing calcium, phosphate, and parathyroid hormone if advised
Do not rely on symptoms alone to confirm deficiency
Repeat testing if recommended after treatment or lifestyle changes