hypervitaminosis

n., pl., -ses (-sēz).
Any of various abnormal conditions in which the physiological effect of a vitamin is produced to a pathological degree by excessive intake of the vitamin.

Toxicity due to excessively high intakes of vitamins. A problem with vitamins A, D, B₆, and niacin, at levels of intake from supplements considerably higher than might be obtained from foods, although hypervitaminosis A and D may result from (enriched) foods. See also hypercalcaemia.

A disorder caused by the intake of excessive quantities of certain vitamins, such as the fat-soluble vitamins A and D and the water-soluble vitamin B₆. In very high doses these vitamins are toxic.

A condition caused by the intake of excessive quantities of certain vitamins, such as the fat soluble vitamins A and D.

A condition produced by ingestion or injection of excessive amounts of vitamins; symptom complexes are associated with excessive intake of vitamins A and D.

• h. A — occurs mainly in cats, and is caused by a long-term diet consisting almost entirely of liver. Affected cats show neck pain and stiffness caused by a deforming cervical spondylosis. Other joints may be similarly affected. There is also hyperesthesia, irritability, anorexia, weight loss, and sometimes neurological deficits. Premature loss of teeth has also been reported.
• h. D — caused by overdosing with vitamin D preparations as in milk fever prophylaxis and inappropriate treatment of disorders of dietary calcium and phosphorus, by errors in a diet mix, and oversupplementation of small puppies and kittens. Causes dystrophic soft tissue calcification, particularly nephrocalcinosis with subsequent renal failure. See also enzootic calcinosis.