Thiamine is a water-soluble vitamin and a critical micronutrient. It functions as a cofactor in enzymatic processes that is essential for carbohydrate metabolism energy production, lipid metabolism, and neurotransmitter synthesis, playing a crucial role in the brain and nervous system function. Several factors may precipitate thiamine deficiency including insufficient consumption, decreased absorption, increased requirement during periods of rapid growth, increased loss of thiamine, or destruction during food processing. Complications associated with thiamine deficiency tend to vary, ranging from mild symptoms such as fatigue, irritability, and cognitive disturbance to severe manifestations including neurological and cardiovascular symptoms that are associated with high mortality. Diagnosis can be difficult, as symptoms are frequently nonspecific or overlap with other conditions. Therefore, thiamine replacement therapy should be promptly started when deficiency is clinically suspected to prevent severe complications. Strategies to prevent thiamine deficiency include mandatory and voluntary food fortification, supplementation programs for high-risk groups, and dietary modification. An important strategy is to also educate the public about the importance of thiamine in the diet and how to recognize early symptoms of deficiency. Screening and monitoring should be implemented to identify thiamine deficiency in high-risk groups especially among communities with limited dietary diversity. Education and training of healthcare providers about the clinical manifestations, risk factors, and treatment protocols is important for early identification and prevention of complications.