Defining Vitamin D Insufficiency in School Age Children: A Randomized Placebo Controlled Trial of Vitamin D3
Condition: Healthy
Intervention: Vitamin D3 1000 IU; Placebo Tablet
Intervention description: Vitamin D3 1000 IU Tablet once daily for 6 months; Placebo Tablet once daily for 6 months
Intervention MeSH terms: Vitamin D; Cholecalciferol
Phase: Phase 1
Study type: Interventional
Primary purpose: Diagnostic
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Enrollment: 157.0
Sex: All
Minimum age: 8 Years
Maximum age: 14 Years
Healthy volunteers: Accepts Healthy Volunteers
Keywords: Vitamin D Deficiency; Vitamin D Insufficiency; Child; Adolescent; African American; Caucasian; Definition; Preadolescent

Summary:

      The study objective is to characterize the threshold levels of serum 25-hydroxyvitamin D for
      the definition of vitamin D insufficiency in 8-14 year old African American and Caucasian
      children.

      We propose a 6 month randomized placebo controlled trial of vitamin D (vitamin D3 1000 IU/day
      vs. placebo) initiated during October through March (during fall and winter) in 8 to 14 year
      old African American and Caucasian children. The results of the trial will help establish the
      cutoff threshold value of serum 25(OH)D for defining vitamin D insufficiency in preadolescent
      and adolescent children. Safety of vitamin D supplementation will be assessed by measuring
      serum calcium at 0, 2 and 6 months and by monitoring for adverse events. Currently
      recommended adequate intake for vitamin D of 200 IU daily may not meet the body's daily needs
      for vitamin D. Therefore, it is likely that a higher level of daily vitamin D intake may be
      needed to meet the body's skeletal and non-skeletal demands for vitamin D. Determining the
      dietary required intake of vitamin D for the prevention of vitamin D insufficiency during
      childhood has immense public health potential for addressing health disparities and ensuring
      better bone health during adulthood. The primary outcome measure will be serum 25(OH)D and
      parathyroid hormone (PTH). The secondary outcome measures will include: markers of bone
      formation (serum P1NP) and bone resorption (serum CTX).We will also examine differences in
      serum 25(OH)D, PTH, and markers of bone turnover in African American vs. Caucasian children.
    

Eligibility criteria:

        Inclusion Criteria:

          -  Age: 8-14 years

          -  Race: African American or Caucasian

          -  Children not taking multivitamins for at least 1 month before enrollment and agree not
             to start any multivitamin supplements during the 6-month trial period.

          -  Children who are on multivitamins can be considered for enrollment only if they are
             able to and agree to stop their multivitamin tablet for a 1 month washout period prior
             to enrollment.

          -  Absence of chronic diseases that could affect growth or calcium or vitamin D
             metabolism

        Exclusion Criteria:

          -  Hepatic or renal disease

          -  Metabolic rickets

          -  Malabsorptive disorders (Crohn's disease, cystic fibrosis and celiac disease) or
             cancer

          -  Treatment with anticonvulsants or systemic glucocorticoids