> For the complete documentation index, see [llms.txt](https://www.thiamine.wiki/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.thiamine.wiki/thiamine-basics/thiamine-basics/introduction-to-thiamine/4.-biochemistry/4.1-role-in-metabolism.md).

# 4.1 Role in Metabolism

Thiamine serves as an indispensable cofactor for several enzymes that drive carbohydrate, amino acid, and lipid metabolism. Its central role is in **energy production**, particularly in oxidative decarboxylation reactions that feed into the **citric acid cycle (Krebs cycle)**, which generates ATP for cellular energy.

Without adequate thiamine, pyruvate and other intermediates accumulate, leading to lactic acidosis, impaired mitochondrial function, and neuronal energy crisis—a hallmark of thiamine-deficient states.