Please select the eligibility criteria that correspond to the clinical trial below.
Title: Randomized Placebo-controlled Trial of Maternal Vitamin D Supplementation During Pregnancy and Lactation to Improve Infant Linear Growth in Dhaka, Bangladesh.
Brief Summary: The primary aims of this study are: 1) to determine whether maternal prenatal vitamin D3 supplementation (4200 IU/week, 16,800 IU/week, or 28,000 IU/week) versus placebo increases or decreases infant length at 1 year of age, and 2) to determine whether maternal postpartum vitamin D3 supplementation (28,000 IU/week) versus placebo increases or decreases length at 1 year of age among infants born to women who received vitamin D 28,000 U/week during pregnancy. Infants enrolled in the study will be followed for 2 years to document the persistence of any observed effects measured at 1 year of age. This study aims to enroll 1300 pregnant women in the 2nd trimester at a maternity hospital in Dhaka. Participants will be randomized to one of three doses of vitamin D3 (4200 IU/week, 16,800 IU/week, or 28,000 IU/week) or placebo throughout pregnancy. Women in the 28,000 IU/week group will be additionally randomized to either placebo or a continuation of 28,000 IU/week for 6 months postpartum. In addition to linear length, the trial will include analyses of inflammatory and hormonal determinants of infant growth, epigenetic phenomena that affect vitamin D metabolism, and diarrheal and respiratory morbidity in the infants.


Options:
A: Inclusion Criteria:

* Women aged 18 years and above.
* Gestational age of 17 to 24 completed weeks estimated based on recalled last menstrual period (LMP) and/or ultrasound.
* Intends to permanently reside in the trial catchment area for at least 18 months.

Exclusion Criteria:

* History of medical conditions that may predispose the participant to vitamin D sensitivity, altered vitamin D metabolism and/or hypercalcemia, or history of renal calculi.
* High-risk pregnancy based on one or more of the following findings by point-of-care testing:

  * Severe anemia: hemoglobin \<70 g/L assessed by Hemocue
  * Moderate-severe proteinuria: ≥ 300 mg/dl (3+ or 4+) based on urine dipstick
  * Hypertension: systolic blood pressure ≥140 mm Hg and/or diastolic blood pressure ≥90 mm Hg
* Multiple gestation, major congenital anomaly, or severe oligohydramnios based on maternal history and/or ultrasound.
* Unwillingness to stop taking non-study vitamin D or calcium supplements or a multivitamin with calcium and/or vitamin D.
* Currently prescribed vitamin D supplements as part of a physician's treatment plan for vitamin D deficiency.
* Previous participation in the same study.
B: Inclusion criteria

* Currently lactating mothers at least 18 years of age
* Willing to continue exclusively breastfeeding their infant throughout the study interval
* The infant is 1-6 months of age at the beginning of the study
* Willing and able to participate in all aspects of the study
* Mother and infant are in good health, as determined by the study investigator
* Have been provided with, understand, and have signed the informed consent for themselves and their child.

Exclusion criteria

* Have recently travelled (within the preceding 30 days) or plan to travel south of 35 degrees north latitude during the study interval
* Have recently or plan to engage in indoor tanning
* Are currently taking medications that affect vitamin D metabolism, like steroids, anticonvulsants, or barbiturates
* Are nursing multiple infants (e.g. twins)
* Are taking greater than the daily recommended intake of 1000 mg elemental calcium as calcium supplements
* Are taking greater than the standard daily dose of 400 IU of vitamin D found in prenatal vitamins
* Infant weight below 1.67 kg
* Mothers with baseline 25(OH)D levels \>70 ng/ml, and/or infants with baseline 25(OH)D levels \>70 ng/ml
* History of kidney stones
C: Inclusion Criteria:

* Women aged 18 to \<35 years.
* Current residence in Dhaka at a fixed address
* Plans to have the delivery performed at the Shimantik maternity center, and to stay in Dhaka throughout the pregnancy and for at least one month past the date of delivery.
* Gestational age of 26th to 29th (inclusive), estimated based on the first day of the last menstrual period (LMP).

Exclusion Criteria:

* Use of any dietary supplement containing more than 400 IU/day (10 mcg/day) of vitamin D within the month prior to enrolment, or refusal to stop taking supplemental vitamin D at any dose after enrollment.
* Current use of anti-convulsant or anti-mycobacterial (tuberculosis) medications.
* Severe anemia (hemoglobin concentration \< 70 g/L).
* Complicated medical or obstetric history that may increase the risk of preterm birth or labor/delivery complications, based on self-report or clinical assessment by physician (e.g., cardiovascular disease, uterine hemorrhage, placenta previa, threatened abortion, hypertension, preeclampsia, preterm labor, or multiple gestation).
* Prior history of delivery of an infant with a major congenital anomaly, birth asphyxia, or perinatal death (stillbirth or death within first week of life).
D: 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.

Answer: A