Serum 25(OH)D <20 ng/mL (50 nmol/L); insufficiency 20–30 ng/mL.
Risk factors
- • Limited sun exposure, dark skin
- • Obesity, malabsorption, CKD
- • Anticonvulsants, glucocorticoids
History taking
- • Bone pain, muscle weakness, falls
- • Fatigue
Examination
- • General: vitals, pallor, icterus, oedema, lymphadenopathy
- • Focused system examination
- • Look for red-flag findings
Red flags
- • Haemodynamic instability
- • Rapid deterioration
- • Severe pain or new neurological deficit
Differential diagnosis
- • See differentials section per chief complaint
Recommended investigations
- • 25(OH)D, calcium, phosphate, ALP, PTH
- • Consider DEXA if osteoporosis risk
Diagnosis
- • Clinical diagnosis supported by targeted investigations
Initial treatment / management
- • Treat underlying cause
- • Symptomatic relief
- • Patient education
Drug therapy
- • Cholecalciferol 60,000 IU weekly × 8 weeks, then 1,000–2,000 IU/day
- • Calcium 1,000–1,200 mg/day if intake low
Follow-up advice
- • Review in 2–4 weeks or earlier if worsening
- • Monitor response to therapy and adverse effects
Patient counselling
- • Explain diagnosis and natural course in lay terms
- • Red-flag symptoms warranting urgent return
- • Adherence to medications and follow-up
Referral criteria
- • Refer if diagnostic uncertainty, complications, or failure of first-line therapy
Clinical pearls
- • Recheck 3 months after loading dose
References
- • Harrison's Principles of Internal Medicine, 21e
- • NICE / WHO guidelines (current edition)
Educational outpatient guide — verify against local guidelines before clinical use.
