Determination of Free 25(OH)D Concentrations and Their Relationships to Total 25(OH)D in Multiple Clinical Populations KU Leuven
CONTEXT: The optimal measure of vitamin D status is unknown. OBJECTIVE: To directly measure circulating free 25-hydroxyvitamin D [25(OH)D] concentrations and relationships to total 25(OH)D in a clinically diverse sample of humans. DESIGN: Cross-sectional analysis. SETTING: Seven academic sites. PATIENTS: A total of 1661 adults: healthy (n = 279), prediabetic (n = 479), outpatients (n = 714), cirrhotic (n = 90), pregnant (n = 20), nursing home ...