Vitamin A toxicity: mechanism and organ manifestations

THE CONTEXT

Excessive vitamin A intake can overwhelm its limited metabolic and intracellular binding capacity, causing tissue injury.

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Vitamin A has a limited capacity for metabolism. Excessive intake causes accumulation beyond the capacity of intracellular binding proteins.

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Unbound vitamin A causes membrane lysis and tissue damage.

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Central nervous system manifestations include headache, nausea, ataxia, and anorexia, associated with increased cerebrospinal fluid pressure.

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Liver manifestations include hepatomegaly with histological changes and hyperlipidemia.

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Disturbed calcium homeostasis produces thickening of long bones, hypercalcemia, and calcification of soft tissues.

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Skin manifestations include excessive dryness, desquamation, and alopecia.

NEETx

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