Quest Vitamin D3 1,000 IU is a superior supplement of the most bioavailable form of vitamin D. This vitamin is essential for normal development and maintenance of bones and teeth, preventing rickets, osteomalacia, and osteoporosis; it supports breast, colon, prostate, and ovarian health; and it is an important factor in overall health.Recommended Dose (Adults & Children): Take 1 tablet daily.Medicinal Ingredients (each tablet contains):Vitamin D (cholecalciferol) ... 1000 IU/25 mcgNon-Medicinal Ingredients: Microcrystalline cellulose, magnesium stearate.This product contains no artificial preservatives, colours, flavours, or corn, dairy, egg, gluten, shellfish, soy or sulfites.