Methods and compositions for increasing the production or activity of catalase in an animal are disclosed. The methods comprise administering vitamin D to the animal in an amount effective to increase catalase production or activity. Methods for treating catalase deficiency, extending the prime years of an animal's life, promoting health and wellness of an animal, and improving the quality of life for an animal through the vitamin D-mediated increase in catalase production or activity are also disclosed. Methods of screening for vitamin D mimetics based on their ability to increase the production or activity of catalase in cells in a manner similar to vitamin D are also disclosed.
