Vitamin D Supplementation and Physical Function in Older Adults
Condition: Physical Function; Vitamin D Insufficiency
Study type: Interventional
Phase: Early Phase 1

Summary: 
      A growing body of evidence suggests that vitamin D status is important in biologic processes
      involved in the maintenance of physical function. To advance the investigators understanding
      of the role of vitamin D in physical function, the investigators will conduct a feasibility
      pilot study to collect key information to help design a full-scale randomized trial to
      determine whether vitamin D supplementation will delay declines in physical function. The
      primary goals of the pilot study are to determine cost-effective strategies for identifying
      persons at high risk for functional decline with insufficient vitamin D levels, determine the
      serum vitamin D response to a vitamin D supplementation regimen designed to attain sufficient
      vitamin D levels, and provide preliminary data of key functional measures (balance, physical
      performance and muscle power) for the future larger study design. A secondary goal is to
      begin to examine potential mechanisms by which vitamin D supplementation may enhance physical
      performance by exploring the effects of vitamin D supplementation on changes in skeletal
      muscle gene expression.
    

Detailed description: 
      A growing body of evidence suggests that vitamin D status is important in biologic processes
      involved in the maintenance of physical function. However, whether remediation of vitamin D
      insufficiency will improve physical function and the potential mechanisms involved are
      unclear. Previous vitamin D supplementation trials have produced mixed results with respect
      to physical function; however, most trials did not specifically recruit individuals who were
      vitamin D insufficient nor is the potential mechanism of action understood well enough to
      appropriately select those individuals most likely to benefit. To advance our understanding
      of the role of vitamin D in physical function, the investigators will conduct a feasibility
      pilot study to collect key information to help design a full-scale randomized trial to
      determine whether vitamin D supplementation will delay declines in physical function. The
      primary goals of the pilot study are to determine cost-effective strategies for identifying
      persons at high risk for functional decline with insufficient vitamin D levels, determine the
      serum vitamin D response to a vitamin D supplementation regimen designed to attain sufficient
      vitamin D levels, and provide preliminary data of key functional measures (balance, short
      physical performance battery (SBBP) and muscle power) for the future larger study design. A
      secondary goal is to begin to examine potential mechanisms by which vitamin D supplementation
      may enhance physical performance and muscle contractility by exploring the effects of vitamin
      D supplementation on changes in skeletal muscle gene expression using microarrays.
    

Intervention name(s): calcium; Vitamin D plus calcium
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): 600 mg calcium carbonate twice daily (total of 1200 mg/day) for 4 months; 1000 IU of vitamin D3 twice daily (for a total of 2000 IU/day) plus 600 mg calcium carbonate twice daily (for a total of 1200 mg/day)
Intervention MeSH terms: Calcium, Dietary; Vitamin D; Calcium
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: vitamin D; physical performance