Vitamin C (ascorbic acid) is a water-soluble vitamin found in a wide variety of fruit (especially grapefruits, lemons, blackcurrants, oranges and kiwi fruit) and vegetables (e.g. broccoli, green peppers, tomatoes, cabbage, sprouts, and sweet potatoes). Fresh milk is also a good source of vitamin C. Vitamin C is essential for collagen formation and helps to maintain the integrity of connective tissue, bone and dentine.

• Vitamin C is essential for wound healing and facilitates recovery from burns.
• Vitamin C also facilitates the absorption of iron.
• Severe deficiency results in scurvy, which is characterised by haemorrhages and abnormal bone and dentine formation.
• The adverse effects of more mild degrees of vitamin C deficiency are not known.
• Vitamin C is an antioxidant but the benefit of vitamin C supplements is a subject of many claims, with very little evidence.
• Despite claims of benefit, very high doses of vitamin C have not been shown to decrease the incidence or severity of the common cold or to protect against malignant disease or atherosclerosis.
• Very high doses of vitamin C do acidify the urine, may cause diarrhoea, predispose to urinary calculi and can cause iron overload.

Severe dietary vitamin C deficiency leads to scurvy. The body's pool of vitamin C can be depleted within 1-3 months.¹ People suffering with vitamin C deficiency may also have other vitamin deficiencies and malnutrition.

Epidemiology¹

• The incidence of scurvy peaks in children aged 6-12 months who are fed a diet deficient in citrus fruits or vegetables.
• Incidence also peaks in the elderly.
• The UK Low Income Diet and Nutrition Survey carried out between 2003 and 2005 found evidence of vitamin C deficiency in an estimated 25% of men and 16% of women. Another 20% of the population had vitamin C levels in the depleted range.²

Risk factors¹

• Infants who are fed only cow's milk during the first year of life.
• Alcoholism and conforming to food fads.
• Elderly.
• Low-income families, who tend not to buy foods high in vitamin C.
• Vitamin C deficiency has been noted in refugees.
• Cigarette smoking.
• Increased need due to increased utilisation in pregnant and lactating women, thyrotoxicosis, surgery, and burns.
• People with type 1 diabetes and those on haemodialysis or peritoneal dialysis also have increased vitamin C requirements.
• Anorexia nervosa or anorexia from other diseases such as AIDS or cancer.
• Chronic diarrhoea increases faecal loss.
• Iron overload disorders may lead to renal vitamin C wasting.

Presentation of scurvy¹

• Early symptoms are malaise and lethargy.
• Patients develop shortness of breath, bone pain and muscle pain after several months. Myalgias may occur because of reduced carnitine Other symptoms include skin changes with roughness, easy bruising and petechiae, gum disease, loosening of teeth, poor wound healing, and emotional changes.
• Dry mouth and dry eyes may occur.
• In the later stages, jaundice, generalised oedema, oliguria, neuropathy, fever, and convulsions may occur.

Signs

• Skin: perifollicular hyperkeratotic papules, perifollicular haemorrhages, purpura, and ecchymoses are seen most commonly on the legs and buttocks where hydrostatic pressure is the greatest. Poor wound healing and breakdown of old scars may be seen. Alopecia may occur.
• Nails: splinter haemorrhages may occur.
• Gums become swollen, friable and infected, with bleeding; petechiae occur on the mucosae.
• Conjunctival haemorrhage, flame-shaped haemorrhages, and cotton-wool spots may be seen. Bleeding into the periorbital area, eyelids, and retrobulbar space may occur.
• Chest and cardiovascular system: scorbutic rosary (the sternum sinks inwards) may occur in children. High-output heart failure due to anaemia can be seen and hypotension may occur late in the disease.
• Fractures, dislocations, and tenderness of bones are common in children. Bleeding into muscles and joints may be seen. Oedema may occur late in the disease.
• Loss of weight secondary to anorexia is common.

Differential diagnosis

• Clotting factor deficiencies.
• Leukaemia.
• Gingivitis.
• Platelet dysfunction.
• Senile purpura.

Investigations¹

• The plasma or leukocyte vitamin C level can confirm the diagnosis. Levels can be low in patients who have tuberculosis, rheumatic fever or other chronic illnesses, cigarette smokers, and women taking oral contraceptive drugs.
• A positive capillary fragility test is an almost constant finding, and anaemia is common.
• Bleeding, coagulation, and prothrombin times are all normal.
• X-rays are required to assess for fractures and dislocations. X-rays may also show subperiosteal elevation, alveolar bone reabsorption and ground-glass appearance of the bone cortex.

Management

• Ascorbic acid replacement therapy.
• It is rarely necessary to prescribe more than 100 mg daily, except early in the treatment of scurvy.¹
• Patients with scurvy should take ascorbic acid at 100 mg 3-5 times a day until total of 4 g is reached, and then they should decrease intake to 100 mg daily. Parenteral doses are required for those with gastrointestinal malabsorption.¹
• Supplements should be combined with intake of foods high in vitamin C.

Gastrointestinal effects are the most common adverse clinical events associated with acute, high doses of vitamin C given over a short period of time.

Prognosis

• Scurvy is fatal if untreated.
• Patients respond quickly to oral therapy.

Prevention

• The recommended daily intake for vitamin C is 40 mg/day for adults, with an increase in pregnancy to 50 mg/day and, during lactation, to 70 mg/day.
• The recommended upper limit for vitamin C supplements is 2 g/day.

Document references

1. Goebel L et al, Scurvy, eMedicine, Jun 2009
2. Mosdol A, Erens B, Brunner EJ; Estimated prevalence and predictors of vitamin C deficiency within UK's J Public Health (Oxf). 2008 Dec;30(4):456-60. Epub 2008 Sep 23. [abstract]

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