Scurvy symptoms treated by vitamin C-rich foods

Steps:

• Match symptoms (weakness, fatigue, joint pain/swelling, gum issues) to scurvy, a vitamin C deficiency disease.
• Recall scurvy causes collagen breakdown, leading to poor tissue repair and bleeding gums/joints.
• Identify vitamin C as the essential nutrient for collagen synthesis.
• Select food source: oranges provide abundant vitamin C to reverse deficiency.

Why D is correct:

• Scurvy is defined as vitamin C deficiency; oranges supply ascorbic acid, enabling collagen production and symptom relief per nutritional science.

Why the others are wrong:

• A: Iron treats anemia (fatigue, weakness) but not gum/joint swelling from collagen issues.
• B: Calcium supports bone health but doesn't address soft tissue/gum problems in scurvy.
• C: Vitamin D prevents rickets (bone deformities) unrelated to gum bleeding or joint aches here.

Final answer: D