Effect of supplementation with vitamin A or plant carotenes on plasma retinol levels among young Egyptian males.

Thirteen young Egyptian males with initial low plasma retinol level were divided into three groups and received single oral vitamin A dose of 200,000 IU, or carotene supplement in the form of boiled spinach leaves, providing roughly 617 RE/day or carrots providing 394 RE/day. The three supplements were equally effective, when the plasma retinol level was measured 40 days later. On a price basis, the vitamin A capsules and the carrots were much cheaper than the spinach supplement.