Defective Bone mineralisation causes “soft” bones due to insufficient vitamin D. The same process causes rickets in children.
Vitamin D is created from cholesterol by the skin (UV light dependant). Diet has some vit D but not enough.
Risks for low vitamin D
- Malabsorption disorders - IBS
- Chronic Kidney Disease - kidneys add the second hydroxy group
Serum 25-hydroxyvitamin D:
- Less than 25 nmol/L – vitamin D deficiency
- 25 to 50 nmol/L – vitamin D insufficiency
Treatment
Symptomatic patients:
- 50,000 IU once weekly for 6 weeks
- 4000 IU daily for 10 weeks
Maintenance dose of 800-2000 IU per day in continued
Check serum calcium within a month of loading regime. It may be:
- Low in calcium deficiency =
- High in primary hyperparathyroidism previously masked by the vitamin D deficiency
- High in other conditions that cause Hypercalcaemia, cancer, Sarcoidosis, or TB