Vitamin D3 plays an important role in the central nervous system; it's involved in the metabolism of neurotransmitters such as acetylcholine (healthy development of memory), dopamine (pleasure hormone) and serotonin (happy hormone). And who doesn't want more of those? Even beyond these basic quality of life attributes, Vitamin D also helps maintain normal blood levels of calcium for healthy bones and teeth, and phosphorus. If you're female and over 40, it's also likely your doctor or health care provider has made you aware of the role Vitamin D—or lack of Vitamin D—can play in depression, seasonal affective disorder and premenstrual syndrome. We've even added a bit of sweet potato to ours, just to give our easy to swallow tablets a tasty flavor on the way down. (We're nice like that.)