Which parasite is associated with vitamin B12 deficiency due to competition for absorption?

Diphyllobothrium latum is indeed the correct answer, as this parasite can lead to vitamin B12 deficiency through its mechanism of competition for absorption in the intestines. Diphyllobothrium latum, commonly known as the fish tapeworm, is typically acquired by consuming undercooked or raw freshwater fish that contain the larvae. Once ingested, the tapeworm attaches itself to the intestines, where it can inhabit the gastrointestinal tract for years. During this time, it absorbs significant quantities of vitamin B12 from the host's diet, which may lead to a deficiency in the host if not addressed.

This interference in vitamin B12 absorption is particularly concerning, as vitamin B12 is crucial for red blood cell production and neurological functions. Symptoms of deficiency may include anemia and neurological issues, highlighting the parasitic impact.

The other mentioned parasites, like Ascaris lumbricoides, Enterobius vermicularis, and Trichinella spiralis, do not primarily cause vitamin B12 deficiency through a similar mechanism of absorption competition. Instead, they are associated with other symptoms and complications related to their own life cycles and the areas of the body they infest. Ascaris lumbricoides is more commonly linked