Thiamin in Clinical Practice

Abstract

Thiamin is a water-soluble vitamin also known as vitamin B1. Its biologically active form, thiamin pyrophosphate (TPP), is a cofactor in macronutrient metabolism. In addition to its coenzyme roles, TPP plays a role in nerve structure and function as well as brain metabolism. Signs and symptoms of thiamin deficiency (TD) include lactic acidosis, peripheral neuropathy, ataxia, and ocular changes (eg, nystagmus). More advanced symptoms include confabulation and memory loss and/or psychosis, resulting in Wernicke's encephalopathy and/or Wernicke's Korsakoff syndrome, respectively. The nutrition support clinician should be aware of patients who may be at risk for TD. Risk factors include those patients with malnutrition due to 1 or more nutrition-related etiologies: decreased nutrient intake, increased nutrient losses, or impaired nutrient absorption. Clinical scenarios such as unexplained heart failure or lactic acidosis, renal failure with dialysis, alcoholism, starvation, hyperemesis gravidarum, or bariatric surgery may increase the risk for TD. Patients who are critically ill and require nutrition support may also be at risk for TD, especially those who are given intravenous dextrose void of thiamin repletion. Furthermore, understanding thiamin's role as a potential therapeutic agent for diabetes, some inborn errors of metabolism, and neurodegenerative diseases warrants further research. This tutorial describes the absorption, digestion, and metabolism of thiamin. Issues pertaining to thiamin in clinical practice will be described, and evidence-based practice suggestions for the prevention and treatment of TD will be discussed.

Vitamin B1 in critically ill patients: needs and challenges

“…Clinical practise publications related to nutritional supplementation state that patients with suspected or at risk of developing TD should be provided with thiamine [50][51][52]. Malnutrition (starvation or reduced intake, increased loss or impaired absorption), alcoholism, bariatric surgery, refeeding, congestive heart failure, lactic acidosis, neuropathy, renal failure with dialysis and the critically ill are all risk factors for the development of TD.…”

“…The transketolase activation test, or transketolase activity assay, and the pyrophosphate effect test are both indirect methods which monitor the status of TPP. Liquid chromatographic techniques, with a range of separation and detection methods, are direct methods of quantification and are the most commonly described [45,52,111].…”

Micronutrients and neurodevelopment: An update

“…It also plays an important role in muscle contraction, nerve impulse conduction, and glucose absorption by the nervous system. 37 The brain stem, the cerebellum and the brain's limbic system are highly sensitive to vitamin B1 deficiency (pseudohypoxia), and its pathophysiology is similar to a continuous oxygen deprivation. 38 An incorrect vitamin B1 supplementation in soy-based formula showed that thiamin deficiency in infants causes encephalopathy, neuropathy, visual alterations, and death.…”

Micronutrientes y neurodesarrollo: actualización

“…También juega un papel importante en la contracción muscular, la conducción de las señales nerviosas y la absorción de glucosa por parte del sistema nervioso. 37 El tallo cerebral, cerebelo y sistema límbico del cerebro son muy sensibles a su deficiencia (pseudohipoxia), y la fisiopatología es similar a una privación continua de oxígeno. 38 La suplementación errónea de vitamina B1 en fórmulas lácteas a base de soja mostró que la deficiencia de tiamina en los lactantes producía encefalopatías, neuropatías, alteraciones oftalmológicas y muerte.…”