Rheumatology - Osteomalacia

Question 1

What causes osteomalacia?

Answer 1

Insufficient vitamin D

In children causes rickets

Question 2

What is the pathophysiology of osteomalacia?

Answer 2

Reduced vitamin D, patients with darker skin need prolonged sun exposure to generate the vitamin D

Diet does not contain enough vitamin D

Malabsorption disorders and CKD can also cause it

Low calcium causes increased PTH, which promotes calcium reabsorption from bone impairing bone mineralisation

Question 3

In patients who are asymptomatic with risk factors what should be done?

Answer 3

Give maintenance vitamin D without testing

Question 4

What are the typical presenting features of osteomalacia?

Answer 4

Fatigue
Bone pain
Muscle weakness
Muscle aches
Pathological fractures

Question 5

What are looser zones?

Answer 5

Fragility fractures that go partially through the bone

Question 6

What investigations are done for osteomalacia?

Answer 6

Serum 25-hydroxyvitamin D

< 25 - deficiency
25-50 - insufficiency

Question 7

What imaging is done for osteomalacia?

Answer 7

X-rays (may show osteopenia)
DEXA

Question 8

How is osteomalacia treated?

Answer 8

Vitamin D

50,000 IU once weekly for 6 weeks

4000 IU daily for 10 weeks

Question 9

When should serum calcium be checked after giving vitamin D?

Answer 9

Within a month of the loading regime