Evaluation of vitamin C deficiency.
Serum levels of vitamin C are an adequate measurement of clinical status. Vitamin C is a cofactor for protocollagen hydroxylase; it promotes the conversion of tropocollagen to collagen.1 Low values occur in scurvy, malabsorption, alcoholism, pregnancy, hyperthyroidism, and renal failure. Smokers have lower levels than nonsmokers. Patients with scurvy have values <0.2 mg/dL. Principal clinical findings in scurvy include bleeding gums, petechiae, follicular hyperkeratosis, perifollicular hemorrhages beginning on the lower thighs, muscle aches, easy fatiguability, and emotional changes.