Ascaris lumbricoides causes deficiency of:
**Core Concept**
Ascaris lumbricoides is a large intestinal nematode parasite that can cause significant morbidity due to its massive size, which can lead to mechanical obstruction and subsequent malabsorption of essential nutrients.
**Why the Correct Answer is Right**
The correct answer is related to the pathophysiology of Ascaris lumbricoides infection. As these parasites can grow up to 30 cm in length, they can block the intestinal lumen, leading to **mechanical obstruction**. This obstruction can impair the absorption of fats and fat-soluble vitamins, including vitamin A, which is essential for vision, immune function, and epithelial integrity. The impaired absorption of these nutrients can result in deficiency states, including night blindness and impaired wound healing.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because Ascaris lumbricoides is not typically associated with anemia, which is a more common consequence of hookworm infections.
**Option B:** This option is incorrect because while Ascaris lumbricoides can cause intestinal obstruction, it is not primarily associated with an increased risk of colorectal cancer.
**Option C:** This option is incorrect because Ascaris lumbricoides is not typically associated with an increased risk of liver disease, although it can cause biliary obstruction in rare cases.
**Clinical Pearl / High-Yield Fact**
A key clinical correlation to remember is that Ascaris lumbricoides infections are more common in areas with poor sanitation and hygiene, where access to clean water and proper toilet facilities is limited.
**Correct Answer:** D. Vitamin A deficiency.