I agree with Velotti, Vitiello, Berardi, Milone and Musella that thiamine deficiency is an underestimated risk of bariatric surgery. It is better to prevent than to treat vitamine B1 deficiency early on. Also, the risk for thiamine deficiency is chronic after the bariatric procedures, therefore indeed chronic prophylaxis is required. One finding from our systematic research on bariatric Wernicke's Encephalopathy patients was that many patients (up to 30–35%) do not go to follow-up meetings following a bariatric intervention, suggesting that the prophylactic treatment plans for thiamine deficiency should be discussed in the first meeting with the patient [ [1] Oudman E. Wijnia J.W. van Dam M. Biter L.U. Postma A. Preventing Wernicke encephalopathy after bariatric surgery.

Obes. Surg. 2018; 28: 2060-2068

]. Fasting (or extreme dietary restrictions), hyperemesis, infections as a complication on the treatment site, and additional somatic conditions all can lead to a potential risk for bariatric Wernicke's Encephalopathy later on [ [2] Wernicke's encephalopathy: new clinical settings and recent advances in diagnosis and management.

Lancet Neurol. 2007 May; 6: 442-455

].