Effect of vitamin D in fluoride-treated rats.

Fluoridated drinking water (30 mg and 100 mg F per liter) was used to induce rachitic changes in rats fed a vitamin D free diet containing calcium and phosphorus in a ratio of 1 : 1. Supplements of vitamin D3 (70 IU of cholecalciferol per week) completely prevented the rachitogenic effects of fluoride. This protective effect occurred despite evidence that vitamin D enhanced the intestinal absorption of fluoride.