| The acute or long- term administration of excessive
amounts of vitamin D or enhanced responsiveness to normal amounts of vitamin leads to
hypervitaminosis D. Causes
Some infants may be hyper reactive to small doses of vitamin D. In adults,
hypervitaminosis D results from over treatment of hypoparathyroidism and from food faddist
use of excessive doses.
Signs and symptoms
The initial signs and symptoms of vitamin D toxicity are those associated with
hypercalcemia*.
In children, a single episode of moderately severe hypercalcemia may arrest growth
completely for 6 months or more, and the deficit in height may never be fully corrected.
Vitamin D toxicity may be manifested in the foetus. Maternal hypercalcemia also may result
in suppression of parathyroid function in the newborn, with resultant hypocalcemia, tetany
and seizures.
* Excess of calcium
Prevention and treatment
Treatment consists of immediate withdrawal of the vitamin, a low calcium diet,
administration of glucocorticoids, and vigorous fluid support. With this regimen, the
plasma calcium falls to normal and calcium in soft tissue tends to be mobilised.
Conspicuous improvement in renal function occurs unless renal damage has been severe.
Vitamin D
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