DPDoctor's PassportEducation
Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.
RapidMLAMSRAMRCSFoundation

Osteomalacia and vitamin-D deficiency

Essential points for quick revision.

!
Escalate

A patient unable to bear weight with focal hip, groin or thigh pain needs immediate fracture protection and urgent imaging; normal radiographs do not exclude a femoral-neck, sacral or pelvic insufficiency fracture. Tetany, seizure, laryngospasm, prolonged QT, severe hypocalcaemia or profound hypophosphataemic weakness requires monitored acute medical treatment. New neurological deficit with vertebral collapse follows the emergency spinal pathway.

Synopsis

Identify mineralisation failure behind bone pain, weakness and insufficiency fracture, protect mechanically vulnerable sites and correct the specific calcium, phosphate or vitamin-D defect safely.

  • Osteomalacia is inadequate mineralisation of adult osteoid; high-yield clues are diffuse bone tenderness, proximal weakness, waddling gait and insufficiency or Looser-zone fractures.
  • First-line bloods are adjusted calcium, phosphate, alkaline phosphatase, PTH, 25-hydroxyvitamin D, magnesium, renal and liver profiles, interpreted as one physiological pattern.
  • Nutritional vitamin-D deficiency commonly produces low 25-hydroxyvitamin D, raised ALP and PTH and low phosphate, while adjusted calcium may remain low-normal through compensation.

Key red flags

Focal groin or thigh pain, pain on axial loading or sudden loss of walking may represent an incomplete femoral-neck or subtrochanteric insufficiency fracture.

Investigation priorities

01
First-line mineral and organ profileFirst stepFirst line

Distinguish vitamin-D deficiency, calcium deficit, kidney disease and phosphate loss while identifying acute treatment hazards.

02
First-line focal radiographsFirst line

Detect pseudofracture, complete fracture, deformity or a destructive alternative at the symptomatic site.

Management branches

Immediate structuralProtect a painful weak bone

Focal weight-bearing pain, loss of walking or a pseudofracture raises concern for impending completion.

  1. Stop provocative loading, document limb alignment and neurovascular findings and provide safe mobility aids.
  2. Obtain radiographs in two planes and use MRI promptly when a high-risk occult fracture remains possible.
First-line biochemicalDefine the missing substrate

Diffuse pain, proximal weakness or insufficiency fracture suggests mineralisation failure.

Key medicines

Colecalciferol loading for adult deficiencyUse an oral regimen totalling about 300,000 units over six to ten weeks, such as 50,000 units weekly for six weeks, then change to maintenance according to current local guidance.
Colecalciferol maintenanceContinue 800 to 2,000 units orally each day after loading when an ongoing adult risk remains, individualising for diet, absorption, body size and specialist advice.
Open full textbook Answer 2 questions
Sources and review status5 sources · checked 27 Aug 2026 · clinical review pending
Sources

Sources and review status

National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.

Authoring stateRapid draftClinical stateAwaiting reviewJurisdictionUnited Kingdom