Conditions: Vitamin D Deficiency
Keywords: adolescents minority
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 183
Healthy volunteers: yes

Brief summary:
To compare the efficacy of two high dose vitamin D3 regimens (5,000 IU daily vs. 50,000 IU weekly) used clinically for the treatment of vitamin D deficiency versus a low dose of vitamin D3 used for supplementation (1,000 IU daily) in a clinical sample of predominantly Hispanic and black adolescents with vitamin D deficiency \[25(OH)D level \<20 ng/ml\] by assessing change in 25(OH)D levels before and after 8 weeks of treatment.

To compare the effects of vitamin D repletion \[25(OH)D level \>20 ng/mL\] on selected musculoskeletal, cardiometabolic and immune markers in predominantly Hispanic and black adolescents with vitamin D deficiency \[25(OH)D level \< 20 ng/mL\].

Hypothesis 1: Increase in vitamin D level will be associated with improvement in musculoskeletal, cardiometabolic, and immune markers including blood pressure, waist circumference, musculoskeletal symptoms, asthma severity and hand-grip strength.

Detailed description:
Vitamin D is an essential nutrient and pro-hormone that has garnered widespread attention over the past decade for both its known and theorized health benefits. Patients, clinicians and researchers have all been alerted to the increasing prevalence of vitamin D deficiency (defined as level of 25(OH)D \<20 ng/mL) and the significance of the extra-skeletal health effects of vitamin D. Aside from the skeletal impacts of Vitamin D, there has been recent evidence about potential health benefits of vitamin D related to the multiple extra-skeletal roles of this hormone. In fact, vitamin D receptors are found in many organs including brain, heart, skin, small intestine, gonads, prostate and breast as well in almost all nucleated cells including osteoblasts, activated T and B-lymphocytes, and B islet cells. Studies in children and adolescents as well as in adults show associations of vitamin D deficiency with cardiovascular risk factors, musculoskeletal health, asthma, and autoimmune diseases.

While Vitamin D deficiency is quite prevalent, adolescents who are obese or who are darker skinned are consistently shown to have higher rates of vitamin D deficiency than lean and lighter skinned adolescents. Treatment of vitamin D deficiency and maintenance of sufficient levels in adolescents are largely under-studied leaving patients and clinicians without clear evidence-based guidelines to follow.

The goal of this study is to compare the efficacy of different treatment regimens for vitamin D deficiency in our population of predominantly minority adolescents and to examine the effect of correction of vitamin D deficiency on selected extra-skeletal targets of vitamin D action including musculoskeletal, cardiometabolic, and immune function.

Arms:
arm 1: VItamin D3 1,000 IU

1 x day, 8 weeks arm 2: Vitamin D3 50,000 IU

1x week, 8 weeks arm 3: Vitamin D3 5,000 IU

1x day, 8 weeks

Interventions: intervention 1: Vitamin D3
Intervention descriptions: intervention 1: Doses are as mentioned above. Will repeat 3 month cycles of treatment if still deficient at 3 month follow up.

Protocol document: