LAUSR

When we first started to use absorption test formula we found discrepancy in the results in Ching Sun et al.‘s article [1]. We talked about this discrapiancies with them and we started to aply relative delta formula in test: baseline free T4 (fT4) level obtained before ingestion of 1000 mcg LT4 in all pateint, after ingestion hourly blood samples were taken for calculate fT4 level for five hours. Absorption rate was calculated with [(peak fT4 baseline fT4) / peak fT4] × vd formula. After applying this formula, all the results in our and Ching Sun’s article became consistent to exclude LT4 malabsorption. We aplied new formula to our new patients and found the accuracy of formula, we want to share our new case series in 2022. But in our article patient two and five’s absorption test misspelled at the time of writing: patients two’s absorption rate was 36% and patient five’s absorption rate was 97%. According to new formula, patient one and two had LT4 malabsorption. TSH level did not normalizied with high dose LT4 and ading T3 prepation to LT4. Their TSH level normalized with weekly intravenous LT4 administration. The other patients TSH level normalizied with strict drug compleance. These results and observations also clues the new formula’s accuracy.