Millions of Americans take multivitamin/mineral pills each day, but there's been remarkably little solid evidence to back up their purported benefits. Some recent research offers interesting insights into multis and wellbeing.
Vitamin D (typically D3) is found in multivitamin/mineral formulations but is also sold as a single supplement or combined with calcium. Until recently most supplements contained 400 IU, the Daily Value used on labeling. But doses have been increasing.