Handbook of Genetic Counseling/Vitamin C Deficiency

Vitamin C Deficiency (Ascorbic Acid Deficiency, Scurvy) General Information Vitamin C is reducing agent that is easily oxidized or destroyed by heat Deficiency can cause defects in collagen formation Adrenal glands and lenses have high concentrations of Vitamin C Etiology Infants born with adequate stores of Vitamin C if mother's intake was good Breast milk also provides adequate source of Vitamin C Infants not breastfeeding or whose mothers are deficient require supplements Majority of cases occur from 6-12 months Febrile illnesses increase need for Vitamin C Particularly infectious or diarrheal diseases Iron deficiency, cold exposure, protein depletion, and smoking also increase need for intake of Vitamin C Pathology Collagen formed during deficiency is low in hydroxyproline Leads to hemorrhage, defective tooth dentin, and loosening of teeth Endochondral bone formation ceases Bones may become brittle and fracture easily Periosteum becomes loosened and hemorrhages in femur and tibia common Degeneration in skeletal muscles, cardiac hypertrophy, bone marrow depression, adrenal atrophy if severe. Clinical Manifestations Begins with irritability, tachypnea, digestive disturbances, and loss of appetite General tenderness, especially in legs Pain causes pseudoparalysis with legs in "frog position" Swelling and hemorrhage along legs Face appears apprehensive, gums swollen Depression of sternum Petechiae in skin or mucous membranes Hematuria, melena, orbital, or subdural hemorrhages Anemia due to inability to utilize iron or impairment in folic acid metabolism Swollen joints Roentgenographic Manifestations Usually basis of diagnosis of Vitamin C deficiency Changes in long bones especially at knee Begin as simple atrophy Zone of well calcified cartilage appears as thick, irregular white line around bone Difficult to diagnose at this stage Subperiosteal hemorrhages at ends of bone may become more intense as deficiency becomes more severe Diagnosis Based mainly on clinical findings and history of poor intake of Vitamin C Laboratory tests not very good index Can get estimate from amount of urinary excretion of Vitamin C after test does of ascorbic acid Children with deficiency secrete less ascorbic acid than those without Check concentrations 3-5 hours after administration of test dose Differential Diagnosis Arthritis or acrodynia due to pain in limbs exacerbated by movement Rheumatic fever - rare in children under 2 years of age Suppurative arthritis and osteomyelitis Syphilis due to pseudoparalysis - usually occurs at earlier age and has other symptoms Polio - doesn't cause tenderness in limbs Henoch-Schonlein purpura, thrombocytopenic purpura, leukemia, meningococcemia, nephritis also may be considered Prognosis Recovery rapid when treated correctly Pain ceases within few days May take months for subperiosteal hemorrhage to disappear Body growth resumes quickly Unrecognized/untreated cases may lead to death From malnutrition, exhaustion, intercurrent disease Uncommonly have permanent deformity Treatment Can be prevented by providing formula fed infants 25-50 mg ascorbic acid daily Lactating mothers should have minimum intake of 80 mg per day Children and adults need 50 mg per day Therapeutic dose of ascorbic acid is 100-200 mg daily Reference "Vitamin C (Ascorbic Acid) Deficiency." Textbook of Pediatrics (1979):225-228. Notes The information in this outline was last updated in 2002.