Evidence that adverse effects of zinc deficiency on essential fatty acid composition in rats are independent of food intake.

1. Young male rats were fed on diets containing 3.4, 36 or 411 mg zinc/kg for 10 weeks in order to determine whether effects of Zn deficiency on plasma and liver essential fatty acid composition could be distinguished from those of reduced protein and energy intake. 2. Fatty acid analysis revealed that a Zn intake of 3.4 mg/kg (plasma Zn 0.80 v. 1.97 mmol/l in controls fed on 36 mg Zn/kg) resulted in a significant increase in the linoleic acid:arachidonic acid ratio in both plasma and liver phospholipids in comparison with rats fed on 36 or 411 mg Zn/kg. 3. Zn supplementation (411 mg/kg) decreased the linoleic acid:arachidonic acid ratio in plasma phosphatidylserine compared with that of the controls. 4. The previously reported increase in arachidonic acid (mol %) in liver triacylglycerol of Zn-deficient rats was shown to be a function of a reduced liver triacylglycerol pool size; quantitatively, triacylglycerol content of arachidonic acid in the liver was not significantly affected by Zn intake.