Effects of Vitamin D Insufficiency in Man
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 300
- 试验地点
- 2
- 主要终点
- Change in serum 25D
研究概览
简要总结
We would like to determine if vitamin D insufficiency exists in different ethnic groups, if it has an effect on bone mass and muscle function, if it has an impact on the function of the cells of the immune system, and if the functioning level of these systems can be improved by stabilizing the vitamin D levels to within normal limits.
详细描述
Vitamin D is a hormone that can either be made in the skin under the influence of sunlight or absorbed from the diet. Roughly 50% of the U.S. population suffers from an insufficiency of vitamin D and its more active metabolites. This defect can result in disorders in the bones, muscles and immune system. In humans, these disorders usually present themselves as decreased bone mass, decreased muscle strength and increased susceptibility to some infections, respectively.
Therefore, the purpose of this study is to:
- determine, by use of skeletal and immune biomarkers in the blood and urine, whether vitamin D insufficiency exists in differently pigmented ethnic groups; skin pigmentation blocks vitamin D production in the skin;
- determine whether the vitamin D status of the host has an impact on bone mass and muscle function;
- ascertain whether the vitamin D status of the host has an impact on the function of cells of the immune system;
- determine the effects of correction of vitamin insufficiency on the musculoskeletal and immune systems.
All tests are designed to gauge the state of the circulating and urine factors that contribute to overall calcium balance and/or imbalance. This will include screening for the presence or absence of active and latent infection with the agent that causes TB. If evidence of active TB is identified, one of the physician investigators in this study will inform the subject of the outcome of the screening test and this information will be reported to the California State Health Department.
Additionally, blood and related medical information will ultimately be stored in our UCLA Repository (Human Vitamin D Sample Bank) in the CTRC (Clinical Translational Research Center) in order to allow sharing of the cells with other approved researchers. The cells may be used for other future research related to the purposes described above.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Single Group
- 主要目的
- Treatment
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •25D levels <30 ng/ml (Vitamin D sufficient) OR <20 ng/ml (Vitamin D deficient)
- •At least 18 years of age
排除标准
- •Hypercalcemia
- •Hyperparathyroidism
- •Hyperthyroidism
- •Hypercalciuria
- •Renal disease
- •Intestinal malabsorption any disorder that places the subject at risk for developing hypercalcemia or hypercalciuria during standard vitamin D replacement therapy owing to the presence of underlying dysregulated vitamin D metabolism (e.g., sarcoidosis, TB, etc)
结局指标
主要结局
Change in serum 25D
时间窗: 5 weeks
次要结局
- Change in muscle strength by questionnaire(5 weeks)
- Change in fractional urinary calcium:creatinine excretion ratio(5 weeks)
- Change in serum iPTH(5 weeks)
- Change in bone mineral density by biochemistry(5 weeks)
- Change in serum bone biomarkers(5 weeks)
- Change in bone mineral density by DXA scan(5 weeks)
- Change in muscle strength by exam(5 weeks)
- Change in serum 1,25D(5 weeks)
研究者
John Adams, M.D.
Professor
University of California, Los Angeles