Exclusion criteria
The following are the exclusion criteria:
1. Daily supplementation of more than 800 IU of
vitamin D3
2. Serum calcium level above 10.5 mg/dl
3. Hypercalciuria (spot urine calcium/creatinine ratio
above 0.4)
4. Lymphoma, sarcoidosis, tuberculosis (TB),
hyperparathyroidism, celiac disease or malabsorption
syndromes
5. History of kidney stones
6. History of inflammatory back pain
7. Impaired renal function tests (glomerular filtration
rate less than 30 ml/min/1.73 m2)
8. Impaired hepatic function tests
9. Abnormal serum phosphorus, alkaline phosphatase
and parathyroid hormone values
10. Fasting blood sugar above 126 mg/dl
11. Previous spine surgery
12. History of trauma
13. Taking anticonvulsant, anti-TB medications or
vitamin D3 analogues
14. Cauda equine syndrome that requires emergency
surgical decompression