Gerber Good Start Gentle Infant Formula with Iron begins with partially hydrolyzed 100% whey proteins broken down to be easy to digest which may help reduce the risk of atopic dermatitis (the most common allergic disease of infancy); they are called Comfort Proteins and are designed to help avoid spit-up, fussiness, and gas due to whole protein intolerance. This unique formula also contains probiotic B. lactis to support the immune system and digestive health; prebiotic galacto-oligosaccharides (GOS) to support digestive health; expert-recommended DHA & ARA for brain and eye development; nutrition for natural immune system support; and vitamin D to support bone development.