Vitamin D Needs of Early Adolescent Children

Study Overview
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Brief Summary
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While a large percentage of children have low blood vitamin D levels, the significance of these low levels and the impact on health is unclear. The purpose of this project is to determine the effects of varying doses of vitamin D supplementation over 12 weeks on blood indicators of health in white and black children, aged 9 to 13 years, from both the northern and southern US.

Detailed Description
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Vitamin D intakes in children do not meet current US Dietary Reference Intake recommendations and emerging evidence suggests that a significant number of children, particularly those with darker skin pigmentation, have inadequate levels of serum 25-hydroxyvitamin D [25(OH)D]. The optimum level of circulating 25(OH)D has not been clearly defined in children, nor is it known what functional outcome measures are ideal for defining this level, or if these requirements would differ by race. Graded doses of vitamin D3 supplementation will be used in this dual-site, 12-week trial. The investigators hypothesize that a dose-response relationship will be observed between vitamin D supplementation and intermediate endpoints of skeletal health, and that race will modify these responses.

Official Title
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Supplemental Vitamin D and Functional Outcomes in Early Adolescence

Conditions
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Healthy

Intervention / Treatment
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* Dietary Supplement: Vitamin D3


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy Non-Hispanic Male, 10-13 years of age or female 9-11 years of age Within genitalia or breast stage 2/3 Willing to provide blood/urine samples Free from taking vitamin, mineral or herbal supplements Able to swallow tablets Exclusion Criteria: Menarche (females) Known bone diseases or disease known to influence bone metabolism (e.g. cerebral palsy, intestinal malabsorption, juvenile rheumatoid arthritis) Known growth disorder The use of medications that influence bone metabolism (e.g. corticosteroids, Attention Deficit Hyperactivity Disorder (ADHD) medications).

Ages Eligible for Study
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Minimum Age: 9 Years
Maximum Age: 13 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Placebo<br>placebo tablet | Dietary Supplement: Vitamin D3<br>* vitamin D3 supplementation at 400 IU vs 1,000 IU vs 2,000 IU vs 4,000 IU vs placebo for 12-weeks<br>|
| Experimental: 400 IU<br>Vitamin D3 tablet, 400 IU | Dietary Supplement: Vitamin D3<br>* vitamin D3 supplementation at 400 IU vs 1,000 IU vs 2,000 IU vs 4,000 IU vs placebo for 12-weeks<br>|
| Experimental: 1,000 IU<br>Vitamin D3 tablet, 1,000 IU | Dietary Supplement: Vitamin D3<br>* vitamin D3 supplementation at 400 IU vs 1,000 IU vs 2,000 IU vs 4,000 IU vs placebo for 12-weeks<br>|
| Experimental: 2,000 IU<br>Vitamin D3 tablet, 2,000 IU | Dietary Supplement: Vitamin D3<br>* vitamin D3 supplementation at 400 IU vs 1,000 IU vs 2,000 IU vs 4,000 IU vs placebo for 12-weeks<br>|
| Experimental: 4,000 IU<br>Vitamin D3 tablet, 4,000 IU | Dietary Supplement: Vitamin D3<br>* vitamin D3 supplementation at 400 IU vs 1,000 IU vs 2,000 IU vs 4,000 IU vs placebo for 12-weeks<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| serum 25(OH)D |  | 0 weeks | 
| PTH |  | 0 weeks | 
| 1,25(OH)2D |  | 0 weeks | 
| fractional calcium absorption |  | 0 weeks | 
| biochemical markers of bone turnover |  | 0 weeks | 
| serum 25(OH)D |  | 3 weeks | 
| serum 25(OH)D |  | 6 weeks | 
| serum 25(OH)D |  | 9 weeks | 
| serum 25(OH)D |  | 12 weeks | 
| PTH |  | 3 weeks | 
| PTH |  | 6 weeks | 
| PTH |  | 9 weeks | 
| PTH |  | 12 weeks | 
| 1,25(OH)2D |  | 3 weeks | 
| 1,25(OH)2D |  | 6 weeks | 
| 1,25(OH)2D |  | 9 weeks | 
| 1,25(OH)2D |  | 12 weeks | 
| fractional calcium absorption |  | 12 weeks | 
| biochemical markers of bone turnover |  | 3 weeks | 
| biochemical markers of bone turnover |  | 6 weeks | 
| biochemical markers of bone turnover |  | 9 weeks | 
| biochemical markers of bone turnover |  | 12 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| sunlight exposure |  | 0 weeks | 
| dietary data |  | 0 weeks | 
| physical activity data |  | 0 weeks | 
| serum and urinary calcium |  | 0 weeks | 
| body composition |  | 0 weeks | 
| sunlight exposure |  | 3 weeks | 
| sunlight exposure |  | 6 weeks | 
| sunlight exposure |  | 9 weeks | 
| sunlight exposure |  | 12 weeks | 
| dietary data |  | 3 weeks | 
| dietary data |  | 6 weeks | 
| dietary data |  | 9 weeks | 
| dietary data |  | 12 weeks | 
| physical activity data |  | 3 weeks | 
| physical activity data |  | 6 weeks | 
| physical activity data |  | 9 weeks | 
| physical activity data |  | 12 weeks | 
| serum and urinary calcium |  | 3 weeks | 
| serum and urinary calcium |  | 6 weeks | 
| serum and urinary calcium |  | 9 weeks | 
| serum and urinary calcium |  | 12 weeks | 
| body composition |  | 3 weeks | 
| body composition |  | 6 weeks | 
| body composition |  | 9 weeks | 
| body composition |  | 12 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Vitamin D, Adolescent, African American, White