A New Paradigm for Vitamin D Sufficiency: A 6-month, Randomized, Double-blind, Placebo-controlled Study to Investigate Vitamin D Status in Elderly Caucasian Women
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 444
- 试验地点
- 2
- 主要终点
- Compare Vitamin D metabolite ratio (VMR) in Caucasian women (current study) and AA women (from prior study)
研究概览
简要总结
Although the African-American (AA) population tends to have lower serum 25(OH)D levels compared to whites, there is no evidence that the lower 25(OH)D levels in African-Americans are harmful. In fact, skeletal health is superior in AA. It is clear that total serum 25(OH)D concentrations do not reflect the same risk/benefit ratio in AA compared to white women and is, therefore, an inappropriate biomarker in this population.
The investigators wish to investigate whether free 25(OD)D and Vitamin D Metabolite Ratio (VMR, ratio of 25(OH)D to 24,25(OH)2D) are preferable biomarkers to total 25(OH)D. The investigators propose a six month randomized double blinded study.
详细描述
The specific aims of this study are as follows:
- To establish that free 25(OH)D and VMR are similar in black and white populations.
- To characterize the relationships between free 25(OH)D and VMR and two measures of bone health (PTH and BMD) in black and white women.
- To evaluate whether the relationship of free 25(OH)D (and in parallel analyses, VMR) and bone health are stronger than those based on total 25(OH)D.
- To evaluate whether free 25(OH)D and VMR respond to vitamin D intake (dose-response) in a similar manner to total 25(OH)D.
The study population is postmenopausal Caucasian women age 60 and older. This six month study includes four visits. These results will be compared to those from a study in AA women which the investigators are also completing.
There are two study groups. One group will receive vitamin D supplementation, the other a placebo. Subjects will be asked to refrain from taking outside Vitamin D supplements for the duration of the study. If the subject is eligible based on the results from the first two visits, the subject will be randomized into one of these two groups. Randomized subjects will be taking the vitamin D or placebo for a period of 6 months and will have one visit at the 3 month mark and a final visit at the 6 month mark.
At the 3-month visit, the following procedures will be conducted: obtain interim medical and travel history, vital signs, weight, and height measured by the Harpenden Stadiometer, record adverse events and concomitant medications, Fasting blood collection: total 25(OH)D (by Diasorin), PTH, serum calcium and creatinine, Fasting urine collection for calcium and creatinine, and questionnaires: calcium food frequency questionnaire, quality of life questionnaire, falls and flu questionnaires. Subjects will be instructed on how to collect a 24-hour urine sample (for final visit) and collection container will be dispensed. Unused study supplements will be collected and counted, and study supplements will be dispensed based on serum 25(OH)D level algorithm.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Health Services Research
- 盲法
- Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 60 Years 至 90 Years（Adult, Older Adult）
- 性别
- Female
- 接受健康志愿者
- 是
入选标准
- •Ambulatory women older than 60 years of age. Women who are ambulatory with an assistive device such as cane or walker may be included. LMP must be > 5 years ago.
- •Self declared as white.
- •20 nmol/L < Serum 25(OH)D level < 65 nmol/L.
- •Willingness to take study drug and participate for 6 months in the trial.
- •Willingness to refrain from the use of self-administered Vitamin D and Calcium supplements during the trial.
排除标准
- •Serum 25(OH)D levels ≤ 20 nmol/L or ≥ 65 nmol/L.
- •BMD total hip below -2.5 standard deviation (using NHANES III adult young white men and women as the point of reference) or history of osteoporotic fracture.
- •Moderate to severe fracture in one or more vertebrae by Instant Vertebral Assessment on DXA.
- •Treatment with HRT, SERMs, calcitonin, PTH, strontium ranelate, androgens, bisphosphonates, Denosumab or anabolic steroids during 6 months prior to entry.
- •Use of systemic corticosteroids (oral or IV) within the last year at an average dose of greater than 5 mg per day of oral prednisone or equivalent for a period of three months or more prior to screening.
- •Mini-Mental State Exam score below 21
- •Hypercalcemia (serum calcium > 10.6 mg/dl) or history of primary hyperparathyroidism.
- •History of hypercalciuria, kidney stones, or 24hr urine calcium >261 mg/day on screening.
- •History of chronic liver disease, chronic renal insufficiency (GFR<30), Parkinson's, metabolic bone disease (Hyperparathyroidism, Hypoparathyroidism, Paget's disease, Fibrous osteodystrophy, Rickets, Osteomalacia, Osteosclerosis), hematologic tumors, rheumatologic disease requiring steroids, conditions that influence vitamin D absorption like celiac disease and irritable bowel disease, malabsorption or new diagnosis or active treatment of cancer 12 months prior to inclusion.
- •Use of medications that influence bone metabolism (e.g. anticonvulsants).
- •Significant deviation from normal in either: history, physical examination or laboratory tests as evaluated by the Principle Investigator. Participants with a history of uncontrolled hypertension, uncontrolled diabetes, hypercalciuria, nephrolithiasis and active sarcoidosis or tuberculosis will also be excluded.
- •Participation in another investigational trial 30 days prior to screening.
- •Spinal disease that affects interpretation of bone densitometry like scoliosis with a Cobb angle greater than 15o, history of surgery at lumbosacral spine.
- •Bilateral hip replacement.
- •Currently smoking more than 10 cigarettes daily.
- •Currently consuming more than 2 units of alcohol daily. (One unit is equivalent to a standard glass of beer (285ml), a single measure of spirits (30ml), a medium-sized glass of wine (120ml), or 1 measure of an aperitif (60ml)
- •Unable to perform DXA due to excessive body girth/width. Body width on DXA > 25 cm.
- •Patients who are deemed unsafe to perform muscular function testing as evaluated by the investigator.
- •Class III obesity.
结局指标
主要结局
Compare Vitamin D metabolite ratio (VMR) in Caucasian women (current study) and AA women (from prior study)
时间窗: baseline
serum 24,25(OH)2D and serum 25(OH)D will be measured and VMR calculated
Compare free 25(OH)D levels in Caucasian women (current study) and AA women (from prior study)
时间窗: baseline
VDBP will be measured and free 25(OH)D calculated
次要结局
- Relationship between free 25(OH)D and two measures of bone health (PTH and BMD)(baseline)
- Relationship between VMR and two measures of bone health (PTH and BMD)(baseline)
- Relationship between vitamin D intake and Change in Physical Performance Assessment (SPPB)(baseline and 6 months)