Human vitamin C (ascorbic acid) deficiency: Which disease results from the absence of ascorbic acid in the diet?

Introduction / Context:
Ascorbic acid (vitamin C) is a water-soluble vitamin essential for collagen maturation and multiple enzymatic hydroxylation reactions. Deficiency has a characteristic clinical syndrome that is historically significant and remains relevant in malnutrition and certain restricted diets.

Given Data / Assumptions:

• The task is to correctly link vitamin C deficiency to its classical disease.
• Consider common deficiency disorders: scurvy (vitamin C), rickets (vitamin D), beri-beri (thiamine), pernicious anemia (vitamin B12).
• We supply appropriate options since the original list did not include the correct condition.

Concept / Approach:
Vitamin C acts as a cofactor for prolyl and lysyl hydroxylases in collagen synthesis. Without it, collagen triple helices are under-hydroxylated, leading to fragile blood vessels, poor wound healing, bleeding gums, perifollicular hemorrhages, and bone pain in children. This constellation of signs and symptoms is termed scurvy.

Step-by-Step Solution:
Identify vitamin C’s biochemical role in hydroxylation for stable collagen crosslinking.Link deficiency to impaired connective tissue integrity and typical hemorrhagic features.Exclude other deficiency diseases that correspond to different vitamins.Select scurvy as the canonical answer.

Verification / Alternative check:
Clinical reversal with vitamin C supplementation and dietary intake of fruits/vegetables confirms causality; historical naval records document scurvy in sailors deprived of fresh produce.

Why Other Options Are Wrong:

• Pernicious anemia: Vitamin B12-related autoimmune condition, not vitamin C.
• Cataract: Multifactorial etiology; not a classic vitamin C deficiency disease.
• Beri-beri: Thiamine deficiency with neuropathy/cardiomyopathy.
• Rickets: Vitamin D deficiency in children.

Common Pitfalls:
Mixing up water-soluble (C, B-complex) and fat-soluble (A, D, E, K) deficiency syndromes; remember the distinctive hemorrhagic gum and skin findings in scurvy.

Final Answer:
scurvy.