RESUMO
A clinical syndrome that arises insidiously as a result of a severe, prolonged deficiency of thiamine in the diet, manifested in the initial stages by anorexia, malaise, and weakness of the legs, frequently with paraesthesia; there may be slight oedema and palpitations. The disorder may persist in this chronic state or may at any time progress to an acute condition characterized either by cardiac involvement with oedema or by peripheral neuropathy; forms intermediate between these two extremes may also occur. It is thought that the basic cause is the inhibition of a series of enzyme-catalysed cleavages of carbon-carbon bonds in which thiamine diphosphate is a coenzyme. This document is intended primarily as a basis for ensuring adequate thiamine intake among populations in emergency settings. It reviews strategies for preventing thiamine deficiency among refugees and analyses factors influencing success and failure. Also included are a review of the literature on the epidemiology of thiamine deficiency and its signs and symptoms; thiamine's properties and functions and the recommended daily allowance; and a discussion of food sources of this vitamin and its stability. Thiamine deficiency and its prevention and control in major emergencies is the second in an occasional WHO series on the prevention and control of micronutrient deficiencies during emergencies. Reviews concerning scurvy and pellagra are also available
