Intervention Using Vitamin D for Elevated Urinary Albumin Treated With Losartan in Diabetes (IDEAL) (IDEAL)

Inclusion Criteria:

1. Diagnosis of T2DM requiring treatment with at least one oral hypoglycemic medication or insulin
2. Macroalbuminuria as defined as the presence of a UACR greater than 300 mg/gm creatinine (30 mg/mmol creatinine) on two occasions in the last six months
3. Estimated eGFR of 30 to 90 mL/min/1.73 m2

Exclusion Criteria:

1. Positive Pregnancy Test or planning pregnancy in the subsequent 18months (if female)
2. Serum Calcium > 2.45 mmol/L (9.8 mg/dL)
3. Serum Phosphorus > 1.78 mmol/L (5.5 mg/dL)
4. Serum Potassium > 5.5 mmol/L (5 mEq/L)
5. Parathyroid hormone < 20 pg/mL or > 500 pg/mL
6. Hemoglobin A1C > 12%
7. 25-OH Vit D > 50 ng/mL
8. Poorly controlled hypertension defined as systolic blood pressure >= 180 mm Hg or diastolic blood pressure >= 110 mm Hg
9. History of kidney stones
10. History of severe disease like chronic liver disease
11. Active malignancy
12. Active granulomatous diseases like turburculosis and sarcoidosis
13. Recent diagnosis of acute renal failure within 3 months of screening visit
14. Likelihood of renal replacement therapy within 1 year
15. History of parathyroidectomy
16. Currently taking calcitriol or 1,25-dihydroxyvitamin D analog
17. Currently taking calcitonin, bisphosphonates, cinacalcet, teriparatide, glucocorticoids or other drugs that may affect calcium or bone metabolism (subjects may be taking calcium containing phosphate binder or other phosphate binder. Subjects may also be taking stable dose of estrogen/progestin)
18. History of osteoporosis or other bone disorder requiring calcitriol therapy
19. History of allergic reaction to calcitriol, paracalcitol, hectoral, or other 1,25-dihydroxyvitamin D analogs
20. History of allergic reaction to losartan or any other angiotensin receptor blocker therapy
21. Evidence of drug or alcohol abuse