Please select the eligibility criteria that correspond to the clinical trial below.
Title: Vitamin D Dose-Response Study to Establish Dietary Requirements in Infants
Brief Summary: The research team is comprised of an expert nutrition scientist and a pediatrician with expertise in endocrinology. Both have world-class experience in assessing bone mass in infancy. Together they have designed a study to determine how much dietary vitamin D is needed to optimize health in infants. This is important since many infants are born with vitamin D deficiency. At present the dosage of vitamin D that is optimal for infant health is unclear and recent research suggests that vitamin D status very early in life has long lasting effects on bone mass and other health issues. Therefore, in a group of healthy infants, this research team will test which dosage of vitamin D is needed to achieve optimal vitamin D status. Optimal vitamin D status will be based on growth, biomarkers of vitamin D and bone status in blood and also general health. The infants will all be breastfed and begin the study at about 2 weeks of age. At 3 months intervals over the first year of life, each infant will be measured for growth, duration of breastfeeding and supplement use plus have a bone density scan to determine changes in bone growth. The data will be helpful to guide health care professionals in providing the best care possible for their infants. It will also be important to the health of populations since dietary recommendations for vitamin D are used to guide fortification of foods and development of evidence based policy around nutrient recommendations and their implementation.


Options:
A: Inclusion Criteria:

* Male and female adults of all races ages 18 years and older

Exclusion Criteria:

* 1. Pregnant and lactating women.

  2. Current or recent history of hepatic or renal disease

  3. History of taking a daily supplement that contains more than 400 IU vitamin D2 or vitamin D3 within the past month or taking a pharmacologic amount of vitamin D2 or one of the active vitamin D analogs including Zemplar (Paricalcitol), Dovonex (calcipotriol), Hectorol (vitamin D pro hormone)

  4. Subjects who are taking antiseizure medications or glucocorticoids.

  5. Exposure to a tanning bed or tanning on a beach for more than eight hours within the past month.

  6. Known history of elevated calcium. (\> 10.5 mg% (mg/dl))

  7. History of intestinal malabsorption (i.e. Cystic Fibrosis, Fat Malabsorption Syndrome, Crohn's Disease)

  8. Unwilling to consent to this trial
B: Inclusion Criteria:

* Delivery at \> or = 35.0 weeks gestation with birth weight \> or = 2.5 kg
* BMI: 10th - 90th percentile for age and gender
* Ages 4.0 to 8.9 years
* Ethnic distribution of greater Houston area
* Usual calcium intake 600-1200 mg/d based on two 24-hour dietary recalls by phone
* Any regularly taken (daily) vitamins and minerals must be stopped at least 1 month before starting the study

Exclusion Criteria:

* History of any chronic illness.
* Regularly taken (daily) medications (except seasonal allergies).
* Avoidance of dairy products or meat in the diet.
C: Inclusion Criteria:

* Healthy singleton term born infants of appropriate size for gestational age (AGA) according to the Centers for Disease Control growth charts based on weight at birth between the 5th and 95th percentiles for sex; and born to healthy breastfeeding women. This allows us to assess growth and bone mineral accretion without bias of intrauterine growth restriction.

Exclusion Criteria:

* Infants of mothers with history of gestational diabetes or hypertension in pregnancy; chronic alcohol use; malabsorption syndromes due to malabsorption of vitamin D (celiac disease, Crohn's etc.); and multiple births.
* Should any exclusion criteria be identified after recruitment, the infant will be excluded from the main analyzes, but followed in a separate arm as intent-to-treat.
D: Inclusion Criteria:

* Clinical diagnosis of stage 2-5 Chronic Kidney Disease (estimated glomerular filtration rate \[GFR\] between 15 and \< 90 ml/min/1.73m2) based on the new bedside Schwartz formula estimation using serum creatinine and height \[height in cm x 0.413/serum creatinine\]
* 1-21 years of age
* Willingness and ability to provide informed consent and assent

Exclusion Criteria:

* Children less than 1 year of age (in whom risk of vitamin D toxicity may be increased) or greater than 21 years at time of study screening
* Children with a documented history of hypercalcemia or nephrolithiasis
* Children with GI tract discontinuity (ostomy)
* Current pregnancy or pregnancy within the last 12 months
* Children with known anemia-related disorders including sickle cell anemia, thalassemia
* Children with severe 25D deficiency (\< 5 ng/mL) likely to be associated with severe morbidity and requiring prompt high dose vitamin D supplementation, or with 25D levels \> 60 ng/mL which could be associated with increased risk of vitamin D toxicity

Answer: C