SPINA-GD (Peripheral Deiodinase Activity)
SPINA-GD peripheral deiodinase activity (Dietrich 2012): a structure-parameter estimate of step-up T4→T3 conversion from free T4 and free T3; the reference band is ~20–60 nmol/s.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Free T4
- 16.5 pmol/L
- Free T3
- 4.5 pmol/L
Result: SPINA-GD 25.22 nmol/s — within the ~20–60 nmol/s reference band.
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Reference
- ~20–60 nmol/s. Sum activity of the step-up deiodinases.
What you enter
- Free T4
- Free T3
How this is calculated
- Inputs
- Free T4 and free T3 (pmol/L) through the published equation (T3 protein-binding factor 601).
Dietrich JW, Landgrafe-Mende G, Wiora E, et al. Calculated parameters of thyroid homeostasis. Front Endocrinol (Lausanne). 2016;7:57 (companion parameter GD). Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.