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:

* 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.
B: Inclusion Criteria:

* one obese or two overweight parents, 1 year old child

Exclusion Criteria:

* weight effecting diseases
C: Inclusion Criteria:

* Recent delivery of a baby (\~6 months ago)
* A preschooler in the home (2-5 years old), and a current BMI ≥25 (with confirmatory BMI ≥25 measured at baseline
* Knowledge of English
* Regular access to a telephone and mailing address
* Mother's age of 18 or older
* Willingness to participate in a healthy lifestyle correspondence and telephone intervention.

Exclusion Criteria:

* Not meeting inclusion criteria
* Medical conditions preventing mother from walking a mile without assistance
* Conditions preventing the child from regular activity
D: Inclusion Criteria:

1. Willingness to participate
2. 14 to 24 years old at the time of conception
3. \< 32 weeks gestation at the time of enrollment
4. Reside within 1 hour (50 miles) of local Indian Health Service medical facility
5. Willingness to undergo random assignment and participate in all aspects of the study

Exclusion Criteria:

1. Inability to participate in full intervention or evaluation (e.g., planned move, residential treatment, etc.)

Answer: A