Status:
COMPLETED
Vitamin D, Glucose Control and Insulin Sensitivity in African-Americans
Lead Sponsor:
Tufts University
Conditions:
Type 2 Diabetes
Eligibility:
All Genders
40+ years
Phase:
PHASE2
Brief Summary
North American blacks tend to have low blood levels of vitamin D because pigmentation blocks vitamin D production in the skin. They also have higher rates of developing type 2 diabetes and higher rate...
Eligibility Criteria
Inclusion
- African-American by self designation
- Glucose intolerance defined as FPG ≥ 100 mg/dl or A1c ≥ 5.8%
- BMI 25.0-39.9
- Age 40 or older
Exclusion
- Medical Conditions
- Diabetes potentially requiring pharmacotherapy, defined as A1c \> 7%
- Uncontrolled thyroid disease
- Current parathyroid, liver or kidney disease
- Renal stone within 5 years
- Sarcoidosis, current pancreatitis, active tuberculosis, hemiplegia, gout
- Inflammatory bowel disease, colostomy, malabsorption
- Cancer other than basal cell skin cancer within 5 years
- Uncontrolled arrhythmia in past year
- Albinism or other condition associated with reduced skin pigmentation
- Pregnancy over the last 1 year
- Intent to become pregnant
- Menopause onset within 1 year
- Any other unstable medical condition Laboratory Tests
- Fasting plasma glucose \< 100
- Hemoglobin A1c \> 7%
- Laboratory evidence of liver disease (e.g. AST \> 70 U/L or ALT \> 72 IU/L)
- Laboratory evidence of kidney disease (e.g. estimated glomerular filtration rate \< 60 ml/min/1.73 m2).
- Elevated spot urine calcium to creatinine ratio \> 0.38 mg/dl\*
- Abnormal serum calcium (serum calcium \> 10.5 mg/dl)
- Anemia (Hematocrit \< 36% in men, \<33% in women) Medications (use in past three months)
- Estrogen or testosterone
- Prescription vitamin D
- Lithium
- Oral corticosteroids
- Anti-seizure medications
- Unstable doses of psychotropics or phenothiazines
- Cholestyramine Supplements (current use - may discontinue after screening)
- Vitamin D supplements, cod liver oil, calcium supplements Other
- Body mass index less \<25 or \> 39.9
- Consumption of more than 14 alcoholic drinks per week
- Inability to attend all three study visits as scheduled
- Inability to provide written informed consent
- age \< 40 years
- not African-American (by self-designation)
- Participation in another research intervention study
- corresponds to a 24-hour urinary calcium excretion \> 400 mg
Key Trial Info
Start Date :
July 1 2008
Trial Type :
INTERVENTIONAL
Allocation :
ACTUAL
End Date :
February 1 2011
Estimated Enrollment :
100 Patients enrolled
Trial Details
Trial ID
NCT00784511
Start Date
July 1 2008
End Date
February 1 2011
Last Update
November 14 2014
Active Locations (1)
Enter a location and click search to find clinical trials sorted by distance.
1
Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University
Boston, Massachusetts, United States, 02111