Reference Range
Reference ranges for total thyroxine (TT4) are as follows
:
In newborns up to age 14 days: 11.8-22.6 mcg/dL (152-292 nmol/L)
In babies and older children: 6.4-13.3 mcg/dL (83-172 nmol/L)
In adults: 5.4-11.5 mcg/dL (57-148 nmol/L)
Reference ranges for free thyroxine (FT4) are as follows:
In children/adolescents: 0.8-2 ng/dL (10-26 pmol/L)
In adults: 0.7-1.8 ng/dL (9-23 pmol/L)
In pregnant patients: 0.5-1 ng/dL (6.5-13 pmol/L)
Normal value ranges may vary among different laboratories.
SI conversion: pmol/L = 12.9 x ng/dL