Effect of Vitamin D Supplementation on Blood Pressure and HbA1c Levels in Patients With T2D

Effect of Administration of 25(OH) Vitamin on Mean 24 Hour Blood Pressure and HBA1c Levels in Patients With Stable Type 2 Diabetes Mellitus

The effect of administration of vitamin D is tested on the long-term control of blood sugar (as measured by HbA1-c levels in blood) and mean blood pressure (as measured by 24 hour blood pressure profiles)in patients with stable type 2 diabetes mellitus

Inclusion criteria

• Men and women, ages ≥18 years
• Official diagnostic criteria for type 2 diabetes fulfilled in patients on any type of oral or parenteral glucose-lowering treatment
• Independent living at home
• On stable regimen of BP meds (if any) with BP well controlled and/or K supplement (if any) for 2 months and which is deemed unlikely to change during the study
• Stable glucose control for 2 months by any approved method including insulin

Exclusion criteria

• Patients with type 1 diabetes (or insulin-requiring diabetes of unclear type)
• Patients on hemodialysis, with hyperparathyroidism or active cancer disease
• Patients with known metabolic bone disease
• Laboratory evidence of kidney (eGFR < 60 ml/min) or liver disease
• Dietary calcium intake exceeding 1500mg/d (as estimated by dietary history)
• 25(OH) vitamin D levels at baseline > 70 nmol/L
• Calciuria (> 8 mmol/24 hours as measured by 24 hour urine collections)
• Hypo- and hypercalcemias and hypo- and hyperphosphatemias of any cause
• Medications that affect vitamin D metabolism (e.g. antiepileptic drugs, calcimimetics, 1-34 PTH (Forsteo) vitamin D therapy over and above 400U daily 6 months prior to enrollment and during the study)
• Foreseeable need for adaptation of either glucose- or blood pressure lowering during the next 6 months as decided by the family physician or the treating diabetologist - see above
• History of binge eating or wt gain or loss exceeding 6 kg in past 18 months
• Patients on any type of inhibitors of plasma coagulation (i.e. coumarine, heparins)