To assess a patients Thiamine (Vitamin B1) status and determine if they are deficient
Thiamine is a water soluble vitamin. It is found in cereal and meat. Thiamine is readily absorbed by the small intestine by both an active and passive process. The free vitamin occurs in the plasma and in the cell the, predominate form is thiamine pyrophosphate (TPP) which is a cofactor for a number of enzymes. About half of the body store is in skeletal muscle. Excretion is in the urine – TPP dephosphorylated in kidney. Thiamine has a role in carbohydrate metabolism, oxidative decarboxylation of 2-oxo acids and neural function.
Little thiamine is stored in the body and poor nutrition can lead relatively quickly to vitamin deficiency. Alcoholics are an at risk group due to dietary habit and inhibition of thiamine absorption by alcohol. Renal dialysis patients are at risk of water soluble vitamin deficiency and are usually supplemented with thiamine. Marginal deficiency results in malaise, weight loss, irritability and confusion. Gross deficiency leads to beri-beri. The main effects are cardiovascular and neurological.
Thiamine is non toxic in large doses. The main problem with intravenous administration is an anaphylactic reaction.
Adult: 50 – 220 nmol/L
Marginal deficiency at 40 nmol/L
Overt deficiency suggested if 5 nmol/L or less
Whole Blood – EDTA or Lithium Heparin sample.