Vitamin C is required as a cofactor for various enzyme functions. Vitamin C supplies electrons to enzymatic reactions. If these are absent, the enzymes are unable to properly produce their intended end product, and the manifestations of scurvy begin to develop. One of the most important functions of vitamin C is to serve as a cofactor, along with ferrous iron (Fe++), for the enzymes prolyl hydroxylase and lysyl hydroxylase. These enzymes are responsible, respectively, for hydroxylation of the proline and lysine amino acid residues in collagen. If the proper ratio of proline and lysine hydroxylation is not present, the collagen molecule is unable to form a proper triple helix, and its function is compromised. Defective collagen production is the main deficiency responsible for the cutaneous signs of scurvy, because collagen is the major structural protein in blood vessel walls and in the dermis. Vitamin C is also responsible for electron donation in other enzymatic reactions, including those that synthesize tyrosine, dopamine, and carnitine.
Histology: Histology is not required for the diagnosis. Biopsy of a petechial lesion shows perifollicular red blood cell extravasation and a minimal lymphocytic inflammatory infiltrate. If the specimen includes the area around a hair follicle, close inspection will reveal a coiled or corkscrew appearance to the hair follicle. It should be remembered that patients with scurvy have impaired wound healing: After biopsy without proper therapy, the freshly incised skin may take weeks to months to heal, and large ecchymoses typically develop around the biopsy site.
Treatment: Therapy requires the replacement of vitamin C at a dosage of 300 to 500 mg daily until the symptoms resolve. Then start the recommended daily allowance. Patients show rapid improvement. The root cause must be determined, and if the patient does not respond to therapy, serum levels should be rechecked. If they are still low, noncompliance with therapy should be considered. Often, patients with scurvy have an underlying alcoholism, eating disorder, or psychiatric illness that, if not properly addressed, will continue to occur. Patients should see a nutritionist, who can best educate them on the need for a balanced diet and which foods are high in vitamin C. Alcoholics need to be referred to experts who are adept at treating this common problem. Supplementation with the daily recommended amounts can be continued for life, because any excess vitamin C is not stored in the body but excreted by the kidneys. Supplementation ensures the avoidance of further episodes of scurvy.
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