Vitamin D, Insulin Resistance, and Cardiovascular Disease

Vitamin D, Insulin Resistance, and Cardiovascular Disease

In recent years, vitamin D has been shown not only to be important for bone and calcium metabolism but also for homeostasis of critical tissues involved in vascular disease in patients with diabetes. Epidemiological studies indicated the high prevalence of vitamin D deficiency among Type 2 DM patients and suggest an increased risk of cardiovascular disease and hypertension with low vitamin D levels. The objective of this proposal is to evaluate the effects of vitamin D replacement on blood pressure control and vascular disease in vitamin D deficient hypertensive patients with diabetes

This is a double blinded, placebo controlled trial. Patients who meet the inclusion criteria will be randomized to placebo or 25(OH)D3, 4,000 IU/d orally for 16 weeks. Enrolled patients will be tested for 24h-blood pressure, brachial arterial blood flow, vascular inflammatory markers and macrophage inflammatory response to modified-lipoproteins at baseline, middle and at the end of the study.

Inclusion Criteria:

• Type 2 diabetes
• 25 (OH) vitamin D levels < 25 ng/ml
• Age 25 to 80 years
• Not on insulin for diabetes treatment
• HbA1c 5.5% -9.5%
• Mild/moderately increased blood pressure (systolic 120-160, diastolic 80-100) off BP medications

Exclusion Criteria:

• Pregnancy
• Patients with systolic >160 or diastolic >100 mmHg
• High urine calcium or history of recurrent kidney stones
• Cardiovascular disease
• Stage 3 or worse chronic kidney disease