Osteomalacia

Question 1

what is osteomalacia?

Answer 1

defective bone mineralisation “soft bones” due to insufficient vitamin D

Question 2

what does osteomalacia present with?

Answer 2

weak bones, bone pain muscle weakness and aches waddling gait, fractures, fatigue

Question 3

osteomalacia in children prior to growth plates closing lead to?

Answer 3

rickets

Question 4

Pathophysiology of osteomalacia?

Answer 4

vitamin D is created from cholesterol by skin in response to UV. inadequate vit D (chronic kidney disease) or malabsorption disorders mean calcium and phosphate cant be absorbed from intestines and kidneys. this causes defective bone mineralisation. Low calcium causes secondary hyperparathyroidism which results in further reabsorption from bones.

Question 5

what are fragility fractures that go partially through the bone?

Answer 5

looser zones

Question 6

causes of vit d deficiency?

Answer 6

darker skin, low exposure to sunlight, live in cold climates, stay indoors, coeliac, ibd, chronic kidney disease, diet, hypophosphatemic rickets, liver disease, drug induced anticonvulsants

Question 7

investigations serum 25-hydroxyvitamin D?

Answer 7

<25nmol/L- vit d deficiency
25-50nmol/L- vit d insufficiency
75nmol/l or above optimal

Question 8

what may be high in bone disorder?

Answer 8

ALP

Question 9

treatment of osteomalaicia?

Answer 9

Cholecalciferol
50,000 IU once weekly for 6 weeks
20,000 IU twice weekly for 7 weeks
4000 IU daily for 10 weeks

A maintenance supplementary dose for of 800 IU or more per day should be continued for life after the initial treatment.

Patients with vitamin D insufficiency can be started on the maintenance dose without the initial treatment regime.