(out of stock) Vitamin D (or the sunshine vitamin as its often referred to) is the only vitamin produced naturally by the human body, and technically classified as a hormone. Our superior combination has been formulated to work synergistically within the body, primarily to aid in the development and maintenance of healthy bones. With added zinc, NOW CAL-MAG +D is a phenomenal all around calcium supplement, as well as a significant contributor to attaining structural longevity.