AOR's Vitamin D3 is derived from sheepskin oil collected during shearing. It is rapidly converted in the body to the active hormone 1 25-dihydroxycholecalciferol and helps in the development and maintenance of bones the absorption and use of calcium and phosphorus and is a factor in the maintenance of good health. Essential for proper bone growth and maintenance - Vitamin D3 in a convenient liquid form for all ages - Supports the immune system - Available in Adult and Children's formulas - Includes calibrated dropper for accurate dosing Amount: 0.2 ml Vitamin D3 (Cholecalciferol) 1000 IU/25 mcg Non-medicinal ingredients: medium chain triglycerides dl-?-tocopherol. Suggested Use: (Adult): Take 6 drops (0.2 mL) per day with food or as directed by a qualified health care practitioner.