Which vitamin deficiency is characterized by swollen gums and joint pain?

The correct choice is associated with a deficiency in Vitamin C, also known as ascorbic acid. This vitamin is essential for the synthesis of collagen, which is vital for maintaining healthy connective tissues, including the gums and joints. A deficiency in Vitamin C leads to scurvy, a condition that exhibits symptoms such as swollen gums, joint pain, fatigue, and easy bruising. The swollen gums arise due to weakened structural integrity of the gum tissue, while joint pain results from the lack of collagen and other connective tissue support necessary for joint health. Ensuring adequate intake of Vitamin C through fruits and vegetables is important for preventing these symptoms and maintaining overall health.

In contrast, the other vitamins mentioned do not typically present these particular symptoms when deficient. Vitamin A plays a crucial role in vision and immune function, Vitamin D is primarily involved in calcium metabolism and bone health, and Vitamin B12 is essential for red blood cell formation and neurological function, but none are directly linked to swollen gums and joint pain in the way that Vitamin C is.