Osteomalacia

Question 1

What is osteomalacia?

Answer 1

It is defined as a condition in which there is decreased bone mineral content secondary to decreased vitamin D levels

Question 2

How is vitamin D produced?

Answer 2

It is created from cholesterol by the skin in response to UV radiation

Question 3

What are the three functions of vitamin D?

Answer 3

It is involved in calcium and phosphate absorption within the kidneys/intestines

It is invovled in regulating bone turnover

It is involved in promoting bone reabsorption

Question 4

What is the pathophysiology of osteomalacia?

Answer 4

The vitamin D deficiency leads to reduced serum calcium and phosphate levels

Due to the fact that calcium and phosphate are required for bone construction, reduced levels lead to defective bone mineralisation

Question 5

What is the pathophysiological consequence of osteomalacia?

Answer 5

The reduced calcium levels additionally result in secondary hyperparathyroidism due to the fact that the parathyroid hormone tries to increase calcium levels through secretion of parathyroid hormone

This hormone stimulates increased bone reabsorption, which causes further bone demineralisation

Question 6

What eight risk factors are associated with osteomalacia?

Answer 6

Dark Skin Complexion

Dietary Vitamin D Deficiency

Decreased Sunlight Exposure

Inflammatory Bowel Disease

Coeliac Disease

Chronic Kidney Disease

Liver Disease

Anticonvulsant Administration

Question 7

What are the six clincial features of osteomalacia?

Answer 7

Fatigue

Bone Pain

Muscle Pain

Proximal Myopathy

Pathological Bone Fractures

Waddling Gait

Question 8

What are the two investigations are used to diagnose osteomalacia?

Answer 8

Blood Tests

X-Ray Scans

Question 9

What five blood test reuslts indicate osteomalacia?

Answer 9

Decreased 25-Hydroxyvitamin D Levels

Decreased Calcium Levels

Decreased Phosphate Levels

Increased ALP Levels

Increased PTH Levels

Question 10

What is the gold standard investigation used to diagnose osteomalacia?

Answer 10

25-Hydroxyvitamin D Blood Test

Question 11

What 25-hydroxyvitamin D level indicates vitamin D insufficiency?

Answer 11

25nmol/L - 50nmol/L

Question 12

What 25-hydroxyvitamin D level indicates vitamin D deficiency?

Answer 12

< 25nmol/L

Question 13

What is the feature of osteomalacia on x-ray scans?

Answer 13

Translucent Bands (Looser’s Zones/Psuedofractures)

Question 14

What is the pharmacological management option of osteomalacia?

Answer 14

Vitamin D Supplements

Question 15

Name vitamin D supplements used to manage osteomalacia

Answer 15

Cholecalciferol

Question 16

Describe the vitamin D supplement regimen used to manage osteomalacia

Answer 16

It is recommended that an initial loading dose is required and then a maintenance supplementary dose is continued for life

Question 17

What are the three vitamin D supplement loading doses?

Answer 17

50,000 IU once weekly for 6 weeks

20,000 IU twice weekly for 7 weeks

4,000 IU daily for 10 weeks

Question 18

What is the vitamin D maintenance dose used to manage osteomalacia?

Answer 18

800 IU once daily

Question 19

What is the management option of vitamin D insufficiency?

Answer 19

The maintenance dose vitamin D supplementation is recommended without the initial treatment regimen