Womens Daily Formula begins with the basic formulation Gentle Care and contains maitake mushroom blend extract (beta-glucan), known for its ability to support immune defenses. Also included is a small amount of taurine, an amino acid that may improve athletic performance in physically active women, especially those who follow a plant-based diet. 2000 IU Vitamin D3 Most multivitamins only contain about 400 IU of vitamin D, but Womens Daily Formula includes 2000 IU, so that women can achieve optimal blood vitamin D levels while minimizing the number of supplements they take. (Gentle Care Formula contains 1000 IU of vitamin D2, the vegan form of vitamin D)