Osteomalacia Flashcards
What is osteomalacia?
It is defined as a condition in which there is decreased bone mineral content secondary to decreased vitamin D levels
How is vitamin D produced?
It is created from cholesterol by the skin in response to UV radiation
What are the three functions of vitamin D?
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
What is the pathophysiology of osteomalacia?
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
What is the pathophysiological consequence of osteomalacia?
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
What eight risk factors are associated with osteomalacia?
Dark Skin Complexion
Dietary Vitamin D Deficiency
Decreased Sunlight Exposure
Inflammatory Bowel Disease
Coeliac Disease
Chronic Kidney Disease
Liver Disease
Anticonvulsant Administration
What are the six clincial features of osteomalacia?
Fatigue
Bone Pain
Muscle Pain
Proximal Myopathy
Pathological Bone Fractures
Waddling Gait
What are the two investigations are used to diagnose osteomalacia?
Blood Tests
X-Ray Scans
What five blood test reuslts indicate osteomalacia?
Decreased 25-Hydroxyvitamin D Levels
Decreased Calcium Levels
Decreased Phosphate Levels
Increased ALP Levels
Increased PTH Levels
What is the gold standard investigation used to diagnose osteomalacia?
25-Hydroxyvitamin D Blood Test
What 25-hydroxyvitamin D level indicates vitamin D insufficiency?
25nmol/L - 50nmol/L
What 25-hydroxyvitamin D level indicates vitamin D deficiency?
< 25nmol/L
What is the feature of osteomalacia on x-ray scans?
Translucent Bands (Looser’s Zones/Psuedofractures)
What is the pharmacological management option of osteomalacia?
Vitamin D Supplements
Name vitamin D supplements used to manage osteomalacia
Cholecalciferol
Describe the vitamin D supplement regimen used to manage osteomalacia
It is recommended that an initial loading dose is required and then a maintenance supplementary dose is continued for life
What are the three vitamin D supplement loading doses?
50,000 IU once weekly for 6 weeks
20,000 IU twice weekly for 7 weeks
4,000 IU daily for 10 weeks
What is the vitamin D maintenance dose used to manage osteomalacia?
800 IU once daily
What is the management option of vitamin D insufficiency?
The maintenance dose vitamin D supplementation is recommended without the initial treatment regimen
