Vitamin D Deficiency

• Emory Chldren's Center — Atlanta, Georgia, United States
• University Hospitals Case Medical Center, Case Western Reserve University — Cleveland, Ohio, United States

• Massachusetts General Hospital — Boston, Massachusetts, United States

• Mayo Clinic — Rochester, Minnesota, United States

• Virginia Commonwealth University Health System — Richmond, Virginia, United States

• Tianjin Medical University Eye Hospital — Tianjin, Tianjin Municipality, China

• Massachusetts General Hospital — Boston, Massachusetts, United States

Not specified

• Creighton University Medical Center — Omaha, Nebraska, United States

• Beijing Friedship Hospital — Beijing, Beijing Municipality, China

• Human Dietary Studies Facility, School of Food and Nutritional Sciences, University College Cork — Cork, Ireland