Urinary calcium response to high dose vitamin D3 with calcium supplementation in patients with multiple sclerosis.

Objective: To characterize the effect of vitamin D(3) intake on urinary calcium:creatinine ratios across predefined ranges of serum 25(OH)D.

Design: Patients with multiple sclerosis (n=25) received escalating doses of vitamin D(3) (4000-40,000IU/d) with calcium (1200mg/d).

Results: Urinary calcium:creatinine was driven by increased 25(OH)D when concentrations were <75nmol/L (r=0.