MBDP	Metabolic Bone Disease of Prematurity
NEC	Necrotizing Enterocolitis
BPD	Bronchopulmonary Dysplasia
NICU	Neonatal Intensive Care Unit
QUS	Quantitative Ultrasound
VLBW	Very Low Birth Weight
ESPGHAN	European Society for Paediatric Gastroenterology, Hepatology, and Nutrition
Ca	Calcium
P	Phosphorus
ALP	Alkaline Phosphatase
PTH	Parathyroid Hormone
FGF23	Fibroblast Growth Factor-23
TRP	Tubular Reabsorption of Phosphate
BIA	Bioelectrical Impedance Analysis
TPN	Total Parenteral Nutrition
SMA	Spinal Muscular Atrophy
BSID	Bayley Scales of Infant Development
MDI	Mental Development Index
PDI	Psychomotor Development Index
VDD	Vitamin D Deficiency
25(OH)D	25-Hydroxyvitamin D
IU	International Units
D2	Ergocalciferol
D3	Cholecalciferol
DPDIA3	Protein Disulfide Isomerase A3
CNS	Central Nervous System
MPS	Mucopolysaccharidosis
DBP	Vitamin D Binding Protein
AUROC	Area Under the Receiver Operating Characteristic Curve
EEG	Electroencephalogram
MRI	Magnetic resonance Imaging
B-ALP	Bone-Specific Alkaline Phosphatase
PTHrP	Parathyroid Hormone-Related Protein
CaSR	Calcium-Sensing Receptor
Mg	Magnesium