Thiamine deficiency occurs where the diet consists mainly of milled white cereals, including polished rice, and wheat flour, all very poor sources of thiamine. Polished rice refers to rice which has been milled to remove the husk, bran, germ, and varying amounts of the nutrients contained in them, leaving a starch-rich grain.
Vitamin B1 deficiency is explained by the fact that thiamine is an essential cofactor for the enzyme pyruvate dehydrogenase that allows oxidation of pyruvate to acetyl CoA. This is a key step in the process that allows energy production, in the form of ATP, from glucose oxidation. In the absence of thiamine this reaction cannot proceed and instead, pyruvate accumulates.
Pyruvate dehydrogenase (PDH) is a key mitochondrial enzyme responsible for the conversion of pyruvate to acetyl-CoA and the enzyme is therefore essential in facilitating aerobic metabolism. Thiamine, or vitamin B1, is a crucial cofactor for pyruvate dehydrogenase. In the absence of thiamine, the conversion of pyruvate to acetyl-CoA is inhibited and lactate is produced.
In acute deficiency, pyruvate accumulates and is metabolized to lactate, and chronic deficiency may cause polyneuropathy and Wernicke encephalopathy.
Increased methylmalonic acid - Vit. B12 deficiency
Increased Phenylpyruvate - Phenylketonuria
Increased Uric acid - Hyperuricemia