The rate of protein insufficiency ( transthyretin concentration less than 20 mg/dL ) did not differ statistically between children receiving test or conventional substitute ( recruitment 51.8 % vs 53.6 % ; end of the trial 44.4 % vs 50.0 % ) but mean transthyretin recovered over 20 mg/dL in children who received the test substitute , increasing from 19.1 to 20.7 mg/dL ( mean change , 1.6 mg/dL ; 95 % confidence interval 0.4 to 2.8 mg/dL ) .