Read the given paragraph and answer the following questions.

The essential role of vitamins in the human body, ranging from supporting visual health and immune function to ensuring bone strength and effective blood clotting, underscores their critical importance in maintaining overall health and preventing a spectrum of diseases.Vitamin A is pivotal for maintaining eye health and bolstering the immune system, with a deficiency leading to xerophthalmia, which manifests as dry eyes, night blindness, and in severe cases, total blindness due to corneal scarring. This vitamin, found abundantly in leafy greens, orange vegetables, dairy, and fish, is vital for not only visual acuity but also for reducing susceptibility to infections. In parallel, Vitamin K plays a critical role in blood clotting and bone health, essential to prevent excessive bleeding and ensure bone density. Meanwhile, Vitamin C's importance cannot be overstated, given its key functions in immune support, tissue repair, and combating scurvy, a condition highlighted by fatigue, joint swelling, and dental problems. Simultaneously, Vitamin D's role in calcium absorption underscores its necessity for bone health, preventing Rickets in children and Osteomalacia in adults, further enhancing immune function and offering potential protection against cancer.