"Powerful D-3 - Known as the ""sunshine vitamin,"" this high potency Vitamin D3 provides 250 mcg, or 10,000IU, of the same type of D Vitamin synthesized by the body through sun exposure. Vit D3 may be particularly helpful to persons with limited access to the sun. Immune Health Formula - Count on KAL Ultra D3 Vitamin for your daily immune support. This biologically active form of Vitamin D may help support a vibrant, healthy immune system so you can feel your best. Bone Support & More - One of the more popular bone supplements for women and men, Vitamin D-3 may help support the body's ability to absorb calcium for skeletal formation, strong bones and teeth. Pair it with Vitamin K2 for ever greater support."