What Are the Dangers of Diluted Baby Formula?

By Jan Sheehan
Hemera Technologies/AbleStock.com/Getty Images

The American Academy of Pediatrics recommends that babies be fed breast milk or iron-fortified formula until at least age 1, but formula can get expensive. Some parents dilute baby formula to save money. This practice can be dangerous, however. Of the three types of formula, powdered and concentrated liquid require adding water. If you use either of these types of formula, mix with the exact amount of water recommended on the label.

Diminished Nutrition

Formulas are designed to give babies the proper amount of nutrients for growth and development. Almost all babies do well on formulas for this reason. Watering down formula to make it last longer will affect the nutrition your baby receives. The U.S. Food and Drug Administration notes that feeding your baby diluted formula for an extended period of time can result in slower growth. Most formulas are fortified with iron; babies who drink formula lacking enough iron can develop anemia.

Water Intoxication

Watering down formula to save money can cause a potentially serious condition known as water intoxication. In 2008, a 5-month-old Florida baby almost died from water intoxication after his mother watered down his formula to stretch out the amount she was given by a government program for low-income women. The baby had a seizure and stopped breathing, but was revived at the hospital. According to an article by Lisa Stein in the December 2008 issue of “Scientific American,” water intoxication in infants can cause sodium levels in the blood to drop, leading to seizures, brain damage and possibly death. Pediatricians at Johns Hopkins Children’s Center in Baltimore see three or four cases of seizures in babies every summer due water intoxication. Adding too much water to formula, as well as giving babies straight water, can cause this medical problem.


Babies who drink excessive amounts of fluoridated tap water in formula can develop dental fluorosis, which causes white spots on the baby teeth when they emerge. Fluoride is added to water to prevent cavities; the public water supply is fluoridated in about 70 percent of communities, according to the American Dental Association. Babies exclusively formula-fed, particularly if the formula is diluted with tap water, may develop fluorosis, but it is usually mild and won’t affect the health of your child. Rarely, severe fluorosis can cause pits to form on the tooth’s surface. To reduce the risk of fluorosis, don’t dilute formula with tap water. Mixing formula with low-fluoride bottled water instead of tap water may lessen the chance of fluorosis, but diluting formula with bottled water can still cause nutrient shortfalls and water intoxication.


Ready-to-feed formula doesn’t require mixing with water, but it is the most expensive type of formula. Powder formula is the least expensive. Under-diluting formula can lead to dehydration, cautions the FDA. Don't freeze formula as this can cause a separation of the formula's components. Always look for any changes in the smell, appearance and taste of formula to be sure it's safe to feed your baby. If you’re able to breastfeed, it may be the way to go. Breast milk is low in fluoride and has just the right amount of fluids and nutrients for healthy growth and development.

About the Author

Jan Sheehan is an award-winning medical and nutrition writer, having entered journalism in 1992. She is a former contributing editor for "Parents" magazine. She has also written nutrition articles for "Self," "Fitness," "Ladies' Home Journal," "Health" and other magazines. Sheehan has a Bachelor of Arts in journalism from Purdue University.