Vitamin B12 deficiency is seen in which tapeworm disease

Most infected patients are asymptomatic. Foy percent of fish tapeworm carriers demonstrate low serum levels of vitamin B12, apparently as a result of the competition between the host and the worm for this ingested nutrient. Studies have shown that a worm located high in the jejunum may take up 80% to 100% of vitamin B12 given by mouth. Approximately 0.1% to 2% of patients develop macrocytic anemia. In many, folate absorption is also diminished.Neurologic manifestations of vitamin B12 deficiency occur, sometimes in the absence of anemia. They include numbness, paresthesia, loss of vibration sense, and, rarely, optic atrophy with central scotoma.Ref: Sherris microbiology; 6th edition; Page no: 889