Efficacy of Vitamin D Therapy on Glucose Homeostasis in Obese Adolescents
Condition: Vitamin D Deficiency
MeSH terms: Vitamin D Deficiency
Study type: Interventional

Summary: 
      The purpose of this study is to see whether giving a Vitamin D supplement to vitamin D
      deficient obese children and adolescents will decrease the risk of getting diabetes (Disease
      in which the person has high blood sugar).

      The number of vitamin D deficiency in U.S. children and teenagers has grown dramatically over
      the past 30 years. There are some reports suggesting that vitamin D supplementation in adults
      with pre diabetes (blood glucose higher than normal) and vitamin D treatment will prevent
      diabetes.
    

Detailed description: 
      Participation will involve 3 visits (6 weeks apart) to the Clinical and Translational Science
      Institute (CTSI), which should happen 2-3 weeks after you have consented to participate in
      this study. The total duration of the study and the time you/your child will spend in the
      CTSI will be 2.5 hours for each visit.

      Number of adolescents/children will enroll in this study:20.

      Visit 1 A doctor will perform a complete physical examination. The child will have his/her
      weight and height measured .Blood pressure and vital signs will check each visit.

      Of the 2 hours spent in the hospital, 1/2 hour is allocated to getting measurements, weight,
      and vitals and putting in an intravenous line and drawing fasting labs. The oral glucose
      tolerance test will take about 2 hours. To test for insulin sensitivity (Risk marker of
      Diabetes), oral Glucose Tolerance Test (OGTT) will be done. OGTT is used to diagnose Diabetes
      and Pre Diabetes. The child will first have blood samples drawn, and then will drink oral
      glucose soda. Blood samples will be obtained over 2 hours. A total of 5-7 teaspoons, which is
      25-35 cc of blood will be taken during this test. Of this 15 cc will be drawn during the
      OGTT. A doctor or nurse will be monitoring the child throughout the test. If he/she develops
      low blood sugar, they will be treated appropriately with glucose.

      Blood samples obtained at the start of the OGTT will be used to measure various markers of
      insulin sensitivity, vitamin D level and marker of bone health as vitamin D deficiency can
      causebone loss. This blood will be stored in the CTSI core laboratory in the CTSI for
      duration of this study. The blood samples will be stored without child's name or any other
      identifying information on them. The samples will be destroyed once the study is completed.

      After the OGTT done, your child will receive a one time high dose of vitamin D (group A) or
      placebo (capsule containing no medication) (Group B). This way of treating of low vitamin D
      levels with one time high dose of vitamin D is safe and has been studied in adolescents.

      The child has 50/50 chance to be in either group. Neither he/she nor you will know if he/she
      is getting Vit D or placebo. At week 7, your child needs to return to CTSI for 2nd study for
      physical check-up, blood test and urine test using the same method as the 1st visit. The
      urine testing will be done to test for urinary calcium as this could be a sign of vitamin D
      toxicity.

      After the 2nd study done, your child will be reassigned to alternate treatment group and will
      receive either vitamin D or placebo. That means that if he/she was getting a placebo at the
      first visit then he/she will get a real Vit D this time. If he/she was getting vit D at the
      first visit, he/she will get a placebo at this visit.

      At week 12 after completion of the 2nd course of medication, you and your child will have to
      come back for the final blood and urine study using the same method as the first and 2nd
      study.

      At this your child will have an oral glucose tolerance test, blood and urine tests. The urine
      testing will be done to test for urinary calcium as this could be a sign of vitamin D
      toxicity. If your child has high urine calcium he/she will not be allowed to participate in
      the study We guarantee that your child will receive the treatment for lack of vitamin D
      either the first half or latter half of the study. However, you will not know what medication
      your child will receive during the entire study. We will set an appointment to see us in
      2weeks at the Endocrine clinic; however, it will be not part of the study. We will go over
      the results of the study at that time and will see if any further treatment with Vitamin D is
      required for your adolescent.

      You and your child will have to come back to CTSI at the end of week 12 for post-therapy
      study. After a minimum 10-hour fast, participants will come to the CTSI, during which your
      child will have his/her weight and height measured. Blood Pressure will be measured. Post
      vitamin D therapy OGTT. Vitamin D level and markers for bone health will again be measured
      using same method as day 1. Urine will be collected for urinary calcium level, using same
      method as day 1.
    

Intervention name(s): Vitamin D2; Placebo
Intervention type(s): Drug; Drug
Intervention description(s): Ergocalciferol 5000 units capsules given. 300,000 units PO once.
Other intervention name(s): ergocalciferol, Vitamin D
Intervention MeSH terms: Vitamin D; Ergocalciferols; Cholecalciferol; Vitamins
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Single (Participant)
Primary purpose: Treatment