Vitamin D Retrospective Study and Role With Disease

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01798030
Recruitment Status : Active, not recruiting
First Posted : February 25, 2013
Last Update Posted : February 13, 2018
Information provided by (Responsible Party):
Alice S. Ryan, PhD, Baltimore VA Medical Center

February 21, 2013
February 25, 2013
February 13, 2018
November 2009
November 2018   (Final data collection date for primary outcome measure)
Vitamin D [ Time Frame: Day 1 ]
Vitamin D level ng/dl
Same as current
Complete list of historical versions of study NCT01798030 on Archive Site
Not Provided
Not Provided
  • IGF-1 [ Time Frame: Day 1 ]
    Insulin like growth factor
  • IGF binding proteins [ Time Frame: Day 1 ]
    Insulin Growth Factor Binding protein levels
  • PTH [ Time Frame: Day 1 ]
    Parathyroid Hormone levels
Same as current
Vitamin D Retrospective Study and Role With Disease
Association of Vitamin D With Diabetes, Osteoporosis and Cardiovascular Risk
Vitamin D deficiency is associated with a heightened risk for developing type 2 diabetes, hypertension, and osteopenia/osteoporosis. Vitamin D is made in the skin when it is exposed to sunlight and it is also obtained from the diet and dietary supplements. Older people, individuals with high skin pigmentation, obese and sedentary individuals have low levels of Vitamin D because pigmentation blocks Vitamin D production in the skin, aging and physical inactivity are associated with reduced exposure to sunlight, and obesity is associated with the storage of Vitamin D in fat preventing its utilization by muscle, bone and other tissues that require its metabolic action. These conditions are also associated with heightened risk for developing type 2 diabetes, glucose intolerance, hypertension, and osteopenia/osteoporosis in older and obese individuals. This is particularly heightened in older women who tend to have increased body fat, are more physically inactive and are at high risk for central obesity and its metabolic consequences of diabetes, hypertension and osteoporosis.

The heightened prevalence of obesity in aging especially in postmenopausal women suggests that interventions to raise Vitamin D levels might be preventive of these diseases. Investigators have completed studies of the effects of weight loss and exercise interventions in approximately 400 older women and men over the last 15 years, many of whom are obese. Investigators have data on glucose tolerance, blood pressure and bone density in these studies and stored plasma in which investigators can analyze Vitamin D levels. Vitamin D may be an important risk factor for these metabolic diseases and the availability of these samples for Vitamin D analysis will allow investigators to perform a cross-sectional study to address relationships of Vitamin D levels to glucose intolerance and diabetes, hypertension/blood pressure status, bone mineral density, the degree of obesity, and physical activity status measured as maximal aerobic capacity and accelerometry in these older men and women.

The results of this study have the potential to impact clinical practice in the prevention and treatment of diabetes, hypertension, and osteopenia/osteoporosis. This would circumvent the current dilemma for prevention of these chronic diseases through treatment of obesity, as these data would provide immediate prospects for changing the recommended doses of Vitamin D beneficial for reducing risk for these diseases.

The purpose of this study is to 1) determine the prevalence of Vitamin D deficiency in obese, older men and postmenopausal women and 2) the association of Vitamin D levels to glucose tolerance, blood pressure, bone mineral density, and hyperlipidemia, as well as association with Vitamin D receptor gene polymorphisms affecting metabolic responses to Vitamin D.

Observational Model: Other
Time Perspective: Retrospective
Not Provided
Retention:   Samples With DNA
Vitamin D, IGF-1, and PTH levels will be measured in coded plasma samples belonging to the PI and collaborating Investigators within the GRECC that are stored in our freezers (from previously approved studies: HP-00040261,HP-00040975, HP-00041166 and HP-00041199) . The Nutrition Obesity research center genetics core will determine Vitamin D receptor polymorphisms on de-identified samples. No clinical information will accompany the samples.
Non-Probability Sample
obese, older men and postmenopausal women
  • Vitamin D Status
  • Glucose Tolerance
  • Blood Pressure
  • Bone Mineral Density
  • Hyperlipidemia
Other: Vitamin D
N/A, frozen specimen study
Vitamin D
Specimen analysis
Intervention: Other: Vitamin D
Sorkin JD, Vasaitis TS, Streeten E, Ryan AS, Goldberg AP. Evidence for threshold effects of 25-hydroxyvitamin D on glucose tolerance and insulin resistance in black and white obese postmenopausal women. J Nutr. 2014 May;144(5):734-42. doi: 10.3945/jn.114.190660. Epub 2014 Apr 9.

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
Active, not recruiting
Same as current
December 2018
November 2018   (Final data collection date for primary outcome measure)

Inclusion Criteria: 45-85 years of age

Exclusion Criteria: none

Sexes Eligible for Study: All
45 Years to 85 Years   (Adult, Older Adult)
Contact information is only displayed when the study is recruiting subjects
United States
Not Provided
Plan to Share IPD: No
Alice S. Ryan, PhD, Baltimore VA Medical Center
Baltimore VA Medical Center
Not Provided
Principal Investigator: Alice S Ryan, PhD Baltimore VAMC
Baltimore VA Medical Center
February 2018