Vitamin C deficiency
Vitamin C deficiency: Excerpt from Professional Guide to Diseases (Eighth Edition)
Vitamin C (ascorbic acid) deficiency leads to scurvy or inadequate production of collagen, an extracellular substance that binds the cells of the teeth, bones, and capillaries. It’s essential for wound healing and burn recovery. Vitamin C is also an important factor in metabolizing such amino acids as tyrosine and phenylalanine. It also acts as a reductant, activating enzymes in the body, as well as converting folic acid into useful components.
Severe vitamin C deficiency results in scurvy, evident by hemorrhagic tendencies and abnormal osteoid and dentin formation.
Causes and incidence
This deficiency’s primary cause is a diet lacking in vitamin C-rich foods, such as citrus fruits, tomatoes, cabbage, broccoli, spinach, and berries. Because the body can’t store this water-soluble vitamin in large amounts, the supply needs to be replenished daily. Other causes include:
❑ destruction of vitamin C in foods by overexposure to air or by overcooking
❑ excessive ingestion of vitamin C during pregnancy, which causes the neonate to require large amounts of the vitamin after birth
❑ marginal intake of vitamin C during periods of physiologic stress — caused by infectious disease, for example — which can deplete tissue saturation of vitamin C.
Historically common among sailors and others deprived of fresh fruits and vegetables for long periods of time, vitamin C deficiency is uncommon today in the United States, except in alcoholics, people on restricted-residue diets, and infants weaned from breast milk to cow’s milk without a vitamin C supplement.
Signs and symptoms
Clinical features of vitamin C deficiency appear as capillaries become increasingly fragile. In an adult, it produces petechiae, ecchymoses, follicular hyperkeratosis (especially on the buttocks and legs),anemia, anorexia, limb and joint pain (especially in the knees), pallor, weakness, swollen or bleeding gums, loose teeth, lethargy, insomnia, poor wound healing, and ocular hemorrhages in the bulbar conjunctivae. (See Scurvy’s effect on gums and legs.) Vitamin C deficiency can also cause beading,fractures of the costochondral junctions of the ribs or epiphysis, and such psychological disturbances as irritability, depression, hysteria, and hypochondriasis.
In a child, vitamin C deficiency produces tender, painful swelling in the legs, causing the child to lie with his legs partially flexed. Other symptoms include fever, diarrhea, and vomiting.
Diagnosis
Confirming diagnosis Serum ascorbic acid levels less than 0.2 mg/dl and white blood cell ascorbic acid levels less than 30 mg/dl help confirm the diagnosis.
Dietary history revealing an inadequate intake of ascorbic acid suggests vitamin C deficiency. A capillary fragility test may be performed on the patient’s forearm with a blood pressure cuff; it’s positive if more than 10 petechiae form after 5 minutes of pressure.
Treatment
Because scurvy is potentially fatal, treatment begins immediately to restore adequate vitamin C intake by daily doses of 100 to 200 mg vitamin C in synthetic form or in orange juice in mild disease and by doses as high as 500 mg/day in severe disease. Symptoms usually subside in 2 to 3 days; hemorrhages and bone disorders, in 2 to 3 weeks.
To prevent vitamin C deficiency, patients unable or unwilling to consume foods rich in vitamin C or those facing surgery should take daily supplements of ascorbic acid. The recommended daily allowance is 60 mg/day. Vitamin C supplementation may also prevent this deficiency in recently weaned infants or those drinking formula not fortified with vitamin C.
Special considerations
❑ Administer ascorbic acid orally or by slow I.V. infusion, as ordered. Avoid moving the patient unnecessarily, to avoid irritating painful joints and muscles. Encourage him to drink orange juice.
❑ Explain the importance of supplemental ascorbic acid. Counsel the patient and his family about good dietary sources of vitamin C.
❑ Advise against taking too much vitamin C. Explain that excessive doses of ascorbic acid may cause nausea, diarrhea, and renal calculi formation and may also interfere with anticoagulant therapy.
Pictures
Book Source Details
- Book Title: Professional Guide to Diseases (Eighth Edition)
- Author(s): Springhouse
- Year of Publication: 2005
- Copyright Details: Professional Guide to Diseases (Eighth Edition), Copyright © 2005 Lippincott Williams & Wilkins.
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Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
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