Vitamin B12 is a water-soluble vitamin that is necessary for DNA synthesis, the metabolism of amino acids and fatty acids1 which are required for normal blood formation, cell synthesis, and neurological functions in the human body. A deficiency in vitamin B12, which can occur due to inadequate absorption or intake, can lead to neurological, psychiatric, and hematological disorders. Vitamin B12 deficiency is defined as a serum vitamin B12 level of less than 148 pmol/L. The primary dietary sources of vitamin B12 are meats, fish, shellfish, and dairy products and as such the deficiency has been reported to be the highest among populations with predominantly a vegetarian or vegan diet. In the US, the deficiency rate among vegetarians has been estimated at 60%. At present, the main technical methods used in the detection of vitamin B12 are HPLC, ELISA, etc., these require professional equipment and instruments, and should not be popularized. The immunocolloid gold chromatography technique is simple, fast, and specific, and can be used for the rapid detection of vitamin B12.