Synopsis
Identify clinically meaningful vitamin D deficiency, distinguish osteomalacia from osteoporosis, replace safely and investigate persistent biochemical or skeletal disease.
- Vitamin D deficiency is a biochemical state; osteomalacia is defective mineralisation with bone pain, proximal weakness, fractures and supportive biochemical or imaging features.
- Test people with suspected osteomalacia, hypocalcaemia, relevant malabsorption or another result that will change management rather than screening low-risk adults indiscriminately.
- 25-hydroxyvitamin D is the usual status test; 1,25-dihydroxyvitamin D can be normal or raised in nutritional deficiency and is not a routine screening test.
Investigation priorities
Measure body vitamin D status in a person whose symptoms, biochemical pattern or risk makes the result actionable.
Management branches
Bone pain, weakness, fracture or biochemical abnormality raises possible osteomalacia.
- Assess pain distribution, gait, proximal strength, falls, diet, sunlight, skin exposure, malabsorption, medicines and kidney-liver disease.
- Measure 25-hydroxyvitamin D with calcium, phosphate, ALP, PTH, magnesium and renal function and image focal skeletal pain.
Key medicines
ColecalciferolFor treatment, use a locally approved finite loading regimen drawn from NICE CKS, then move to the documented daily maintenance dose; public-health prevention uses the current SACN intake advice rather than repeated loading.
Calcium supplementUse a divided elemental-calcium amount selected for measured dietary shortfall, hypocalcaemia and the local bone protocol, documenting the salt and elemental content.