Thiamine Replacement Protocol

Introduction to Thiamine Replacement

The American College of Nutrition recommends administering 100-300 mg of thiamine intravenously daily for the first 3-4 days in patients with suspected or confirmed nutritional deficiency 2, 1
In patients with established or suspected Wernicke's encephalopathy, the dose should be 500 mg intravenously three times a day (1,500 mg/day total) for 3-5 days 1
For patients with refeeding syndrome, administer 300 mg intravenously before starting nutrition, then 200-300 mg intravenously daily for at least 3 more days 1

The transition to oral thiamine should be initiated once the patient can tolerate oral intake adequately, acute neurological symptoms have improved, and there is no active vomiting or severe dysphagia that compromises absorption 1
The maintenance dose for mild to moderate confirmed deficiency is 50-100 mg/day orally after confirmed deficiency 1, 3

For patients on parenteral nutrition, standard preparations contain 2-6 mg/day, which is adequate for prevention in stable patients 2, 1
In high-risk patients receiving high-glucose intravenous therapy, consider 6 mg/day to accommodate very high requirements 1
For patients on continuous renal replacement therapy, 100 mg/day is recommended due to significant losses during dialysis 1
Consider 2-3 vials of standard multivitamin preparations daily to achieve an adequate dose 2

Clinical improvement of symptoms (confusion, weakness, neuropathy) is the best indicator of adequate response 1
If laboratory confirmation is required, measure thiamine diphosphate (ThDP) in erythrocytes or whole blood, not plasma thiamine 1, 3
There is no established upper limit of toxicity; excess is excreted in urine 1, 3
Doses >400 mg may induce mild nausea, anorexia, or mild ataxia 1
Anaphylaxis with high intravenous doses is rare 1