Increased Risk for Vitamin A Toxicity in Severe Hypertriglyceridemia

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Abstract
A 48-year-old woman with malabsorption and type V hyperlipoproteinemia developed hypervitaminosis A with a total plasma vitamin A level of 871 .mu.g/dL during therapy with an oral dosage of 18,000 retinol equivalents (60,000 IU) daily. Twelve percent of the total plasma retinol was found to be transported in the chylomicron-very low density lipoprotein (VLDL) fraction, which does not contain retinol-binding protein. For comparison, concentrations of retinyl esters and retinol were determined in nine patients with type V hyperlipoproteinemia and nine control subjects, none of whom were using vitamin A supplements. Both retinyl esters and retinol were significantly elevated in the group with hyperlipoproteinemia (p < 0.0005 in both cases). Eight of these nine patients had retinol present in the chylomicron-VLDL fraction, whereas retinol was not detectable in this fraction in any of the nine normal controls. The data suggest that patients with severe hypertriglyceridemia associated with type V hyperlipoproteinemia are at increased risk for hypervitaminosis A.