Nutritional Pathology Online
Pathology of Vitamin C deficiency
Eat Citrus Fruits everyday and keep Scurvy away:
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|In the past
Scurvy affected sailors on long sea voyages. Vasco Da Gama
Portuguese explorer reached India
sea route and it
is reported that he lost 100
men in the long voyage due to the disease.
James Lind (1716-1794), a British naval surgeon, introduced oranges, lemons and limes into his sailors diet in 1747, preventing the lethal effects of scurvy and earning the name 'limey' for his country-men.
The disease first becomes manifest about three months after a continuous deficient diet.
Human beings share with other primates, the guinea-pig, and certain birds, the inability to synthesize vitamin C.
The main dietary sources of this vitamin are citrus fruits ( orange, lemon, lime, grape fruits), black currants, berriers, guava, strawberries, tomatoes, broccoli, green vegetables, and potatoes.
Pathology of Vitamin C deficiency:
Vitamin C is necessary for the synthesis of collagen and a deficiency leads to Scurvy.
The main clinical effect is a bleeding tendency, the cause of which is probably poor anchorage of the smaller blood vessels in a thin, watery cellular substance devoid of adequate collagen fibres.
The site of bleeding in Vitamin C deficiency varies according to the age of the patient.
Bleeding often first takes place into the skin, being first detected around the hair follicles, which also show follicular hyperkeratosis. There may be a characteristic "saddle" distribution of petechiae on the medial surface of the thighs and buttocks. Cutaneous ecchymoses may follow minor trauma. There is also bleeding into muscles and along fascial planes, particularly at points of mechanical stress.
A very characteristic finding is gingival haemorrhage, which occurs only in those who have teeth. The gingivae become spongy, swollen, and ultimately ulcerated.
The clinical finding of corkscrew hair may be mistaken for Menkes syndrome.
Anaemia is common in patients suffering from Vitamin C deficiency, but this is probably due to multiple nutritional deficiencies. Vitamin C does not have a direct role in haematopoiesis.
The very important effect of vitamin C deficiency is delayed wound healing.
There may be severe bleeding with later superimposed infection. Death occurs in untreated cases, usually from severe infection.
Milk and milk products are often a poor source of vitamin C, especially if the milk has been stored or processed.
Consequently scurvy can develop in infants at about the age of 8 months.
In infantile scurvy the characteristic feature is subperiosteal hemorrhages, which is very painful, these are rare in adults.
On the other hand, although bleeding can occur elsewhere, gingival lesions are not seen in infants unless the teeth have erupted.
Bone lesions are also seen in infantile and early childhood scurvy, since there is an impaired formation of osteoid.
Bone pathology in Vitamin C deficiency - An X-ray of the bone of a patient suffering from vitamin C deficiency show generalized rarefaction due to osteoporosis, which is particularly well marked at the metaphyseal ends of the shaft.
By contrast, the zones of provisional calcification are very dense, in the long bones this density appears as a transverse line at the junction between the epiphysis and the end of the shaft.
There is heavy calcification of the cartilage with foci of fragmented spicules of calcified cartilage forming during the period of retarded longitudinal growth.
The epiphysis may be fractured at the line of junction and undergo displacement and dislocation.
Microscopically, there is little evidence of bone formation either beneath the periosteum or at the margins of the calcified spicules of cartilage in the metaphyseal zone.
Instead there is an accumulation of cells of fibroblast type embedded in a loose-textured, oedematous ground substance.
These cells are osteoblasts, and they start to lay down osteoid as soon as ascorbic acid is administered.
The subperiosteal hemorrhages follow the disruption of the collagenous attachments (Sharpey’s fibres) from the cortex of the bone.
There is also an impairment in the formation of dentin and the teeth may be loosened from the alveolar bone.
Other clinical findings may include fatigue, keratitis, psychosis and pericardial effusion.
|Visit: Pathology of Vitamin A deficiency: Importance of Vitamin A in our daily diet|
Lind and Limeys, Part 1: a brief early history of scurvy and the search for its cure in the 18th century
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