Most infant formulas contain cow's milk or soy milk, as well as vegetable oils, vitamins and minerals, according to WebMD. Infant formulas may also be iron-fortified and contain corn syrup or sucrose.
The Food and Drug Administration regulates infant formula manufacturing to ensure well-balanced total nutrition for babies. The FDA requires all infant formulas contain sources of protein and carbohydrates. In addition to meeting the recommended requirements for vitamins and minerals, some formulas also have added DHA and ARA fatty acids to support brain and nerve development. Cow's milk based formulas are generally appropriate for full-term, healthy babies, while soy-milk formulas provide an adequate alternative for babies who are lactose intolerant, allergic to cow's milk or on vegetarian-based diets.