Mineral nutrition is perhaps the most complex area of animal nutrition. Sows today are capable of a very high production level, much higher than naturally occurs. Because of this we think that minerals must be supplemented to a higher dietary level than is solely available in grains in order to meet the modern sow’s reproductive demands. Research has demonstrated that pigs fed inorganic minerals from an organic source increases the number of live born pigs, reduces days to puberty, gives heavier litter weights, and reduces wean-to-estrus interval. However, too much inorganic mineral can lead to poor reproductive performance. Researchers Mahan and Peters fed sows one of four diets and followed them through 6 parities. The sows that were fed organic minerals (such as Bioplex and Sel-Plex) in gestation and lactation diets resulted in one additional pig per litter when both NRC and Industry requirements were met. When inorganic minerals were fed, the Industry requirements resulted in poor reproductive performance, but the NRC requirements resulted in higher reproductive performance. Conclusively, feeding organic minerals above the NRC requirement will increase reproductive performance. Feeding inorganic minerals in excess may result in detrimental effects on the sow’s reproductive performance.