Effect of Vitamin D Supplementation on Hemoglobin A1c
Condition: Diabetes Mellitus; Vitamin D Deficiency
MeSH terms: Diabetes Mellitus; Vitamin D Deficiency
Study type: Interventional
Phase: Phase 2

Summary: 
      This is a prospective, randomized, non-blinded interventional study that will investigate the
      effect of a vitamin D supplement on HbA1c in patients with uncontrolled type 2 diabetes
      mellitus (DM) and vitamin D deficiency. The goal is to investigate whether correcting vitamin
      D deficiency will alter the HbA1c level in patients with type 2 DM and lower than normal
      vitamin D level. My hypothesis is that correcting vitamin D deficiency decreases HbA1c levels
      in patients with type 2 DM and vitamin D deficiency.
    

Detailed description: 
      The total number of study subjects expected to be enrolled in this study is about 150. Study
      subjects included in this study will be men and women between 34-69 years of age who have
      been diagnosed with type 2 DM based on at least one of the American Diabetic Association
      criteria. These criteria are 1) fasting blood glucose higher than 125 mg/dL once with
      symptoms of diabetes (increased urination, increased appetite, increased thirst) or two times
      without symptoms; 2) random blood glucose more than 200 mg/dL once with symptoms or two times
      without symptoms of diabetes; 3) two hour glucose tolerance test more than 200 mg/dL once
      with symptoms or two times without symptoms; or 4) a random glycosylated hemoglobin more than
      6.5 % two times. The age group for this research was selected based on the review of the
      literature on diabetes and vitamin D. Patients with known primary hyperparathyroidism,
      sarcoidosis, tuberculosis, cancer, potential terminal illness, history of serum creatinine
      more than 2.0 mg/dL, vitamin D supplement more than 200 IU/day, inflammatory bowel disease
      and history of hypercalcemia and kidney stones will be excluded from this study. For this
      project, vitamin D deficiency is defined as serum vitamin D level lower than 30 ng/mL and
      uncontrolled diabetes is defined as HbA1C level above 7.0. Although there is more than one
      recommended normal level of vit. D in the blood, most experts agree that the optimum serum
      level of vitamin D should be above 30 ng/mL. All subjects will be receiving standard of care
      for DM offered to them by his or her physician.

      The investigators will investigate if different but fixed doses of vitamin D (600 IU a day vs
      50,000 IU once every other week) when given to patients with type 2 DM and vitamin D
      deficiency have different effects on HbA1c level at the end of 24 weeks. A baseline blood
      draw, and fasting blood draws will be taken at 12 and 24 weeks for blood sugar levels, Vit D
      levels, and HgbA1c. Subjects with vitamin D deficiency will be randomly assigned to either
      group 1 or 2 and will be supplemented with either 600 IU of vitamin D/day (Group 1) or 50,000
      IU of vitamin D every 2 weeks for 24 weeks (Groups 2). Patients who are not vitamin D
      deficient will be followed as the control group (Group 3) and will not be given any vitamin D
      supplement.Research subjects will be advised not to take any vitamin D or multivitamin while
      participating in this study. Subjects will be given 100 tablets of 600 IU of vitamin D in a
      bottle if they belong to Group 1. If they have been advised to take vitamin D 50,000 IU once
      every 14 days (Group 2), they will be given altogether 13 tablets of 50,000 of vitamin D each
      in a separate brown envelope with date written on the envelop and subjects will be asked to
      take vitamin D only on the date written on the envelop.
    

Intervention name(s): Vitamin D; Vitamin D
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): 600 IU daily oral supplementation; 50,000 IU supplementation bi-monthly
Intervention MeSH terms: Vitamin D; Ergocalciferols; Cholecalciferol; Vitamins
Allocation: Randomized
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Diabetes; Vitamin D deficiency; Hemoglobin A1c