Do you get enough of the powerhouse Sunshine Vitamin? The body manufactures some vitamin D on its own when it is exposed to sunlight—hence the nickname—but for people living in the northern latitudes where wintertime sun exposure is limited, the body's natural vitamin D production may not be enough. Swanson High Potency Vitamin D-3 capsules tackle this problem by supplying an impressive 25 mcg (1,000 IU) of vitamin D-3, the most biologically active type of vitamin D. Vitamin D-3 is an essential bone supporting nutrient that works to absorb calcium efficiently in the body and also supports a healthy immune system.