Vitamin A is present in the skin where it plays a crucial role in epidermal turnover. Nutritional vitamin A deficiency, exposure to sunlight or any ultraviolet (UV) source, oxidative stress, and chronological aging may lead to epidermal vitamin A deficiency. Vitamin A and its endogenous and synthetic derivatives are collectively referred to as retinoids, because the biology of vitamin A was first discovered in the retina. Retinoids function as key regulators of differentiation and proliferation in various tissues. Retinoids may counteract some deleterious actions of UV radiations by physical and biological mechanisms. Topical natural retinoic acid precursors such as retinaldehyde or retinol are less irritant than acidic retinoids and may prevent epidermal vitamin A deficiency due to nutritional deficiency, exposure to sunlight, or any condition leading to free radical production. Retinoids may be combined with other compounds—with complementary actions against aging, nutritional deficiency, and cancer—such as antioxidants, to potentiate their beneficial effects on the skin.