Pure Encapsulations Vitamin D3 enhances calcium absorption and retention, a key nutritional role in supporting healthy bones, and may play a potential role in cardiovascular, colon and cellular health. Vitamin D levels have been shown to decline with age, due primarily to a reduction in either absorption or metabolism by the liver. Decreased exposure to sunlight, a vegetarian diet, or a low intake of vitamin D fortified foods also play a role in inadequate vitamin D levels.Recommended Dosage: 1-5 capsules daily, with meals.Medicinal Ingredients: (per capsule): Vitamin D3 (Cholecalciferol)25 mcg (1000 I.U.).Non-medicinal Ingredients: Hypo-allergenic plant cellulose, Hydroxypropyl methylcellulose, Purified water.Caution: It is recommended that individuals taking more than 2,000 iu Vitamin D per day have their blood levels monitored. If you are pregnant or lactating, consult your health professional before use.