The Effect of a Meal on Vitamin D Absorption
Condition: Vitamin D Deficiency
MeSH terms: Vitamin D Deficiency
Study type: Interventional
Phase: Phase 1

Summary: 
      This study seeks to determine if vitamin D3 absorption in healthy adults will be enhanced in
      the presence of a meal and if the enhancement will be greater when the meal is low as opposed
      to high in fat content. The enhancement will result from increased vitamin D absorption. The
      investigators will test this hypothesis by pursuing the following aims in a 3-mo trial in
      which up to 70 healthy men and women will be randomized to one of the following meal
      conditions under which they will take a monthly oral dose of 50,000 IU of vitamin D3: no meal
      (fasting), a low fat meal, or a high fat meal. The Primary Aim is to identify the meal
      condition (fasting, low-fat, or high-fat meal) under which the 25OHD3 response to
      supplemental vitamin D3 is greatest and most consistent. The Secondary Aim is to determine
      whether vitamin D3 absorption is affected by the meal condition and to determine whether the
      absorption of vitamin D3 predicts the longer-term 25OHD3 response to supplementation.
    

Detailed description: 
      Vitamin D supplements are increasingly recommended to curb widespread deficiency. Decreasing
      the variability in 25OHD responses to supplemental vitamin D would make the supplementation
      process more predictable, and thereby reduce the number of 25OHD measurements and dose
      adjustments that are needed to achieve the targeted 25OHD level. This study seeks to identify
      potential sources of variability in the 25OHD3 response to supplemental vitamin D3 that are
      plausible based on rat studies, but have not been explored in humans. The investigators
      hypothesize that the serum 25OHD3 response to supplemental vitamin D3 in healthy adults will
      be enhanced in the presence of a meal and the enhancement will be greater when the meal is
      low as opposed to high in fat content. The enhancement will result from increased vitamin D
      absorption. The investigators will test this hypothesis by pursuing the following aims in a
      3-mo trial in which up to 70 healthy men and women will be randomized to one of the following
      meal conditions under which they will take a monthly oral dose of 50,000 IU of vitamin D3: no
      meal (fasting), a low fat meal, or an iso-caloric high fat meal. Serum 25OHD3 will be
      measured at baseline and after 1 and 3 mo. A serum vitamin D3 absorption test will be
      performed in each subject after the first dose of vitamin D. The Primary Aim is to identify
      the meal condition (fasting, low-fat, or high-fat meal) under which the 25OHD3 response to
      supplemental vitamin D3 is greatest and most consistent. The Secondary Aim is to determine
      whether vitamin D3 absorption is affected by the meal condition and to determine whether the
      absorption of vitamin D3 predicts the longer-term 25OHD3 response to supplementation.
    

Intervention name(s): cholecalciferol
Intervention type(s): Dietary Supplement
Intervention description(s): 50,000 IU once per month for 3 months
Other intervention name(s): vitamin D3
Intervention MeSH terms: Vitamin D; Cholecalciferol
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Vitamin D; vitamin D deficiency; vitamin D absorption