Distilled vs Purified Water for Baby Formula

What Water to Use for Baby Formula

The American Academy of Pediatrics (AAP) says that most babies can have formula mixed with safe tap water or with bottled water. If you are unsure about your water supply, ask your pediatrician or your local health department. Whichever water you choose, the formula tin's instructions on measuring come first.

Babies under 2 months old, babies born prematurely and babies with a weakened immune system are more vulnerable to germs, so the AAP advises using water that has been boiled and then cooled for them, even when it comes from a bottle.

Can I Use Distilled Water for Baby Formula?

Yes. Distilled water has had minerals removed through evaporation and condensation, and it is safe to mix with formula. The AAP lists bottled water labeled purified, demineralized, deionized, distilled or reverse osmosis as suitable options. Infant formula already contains the minerals babies need, so removing them from the water is not a nutrition problem.

Two things to keep in mind: bottled water is not sterile, so boiling still applies for the higher-risk groups above, and distilled water has essentially no fluoride (see below).

Purified Water for Baby Formula vs Tap Water

Purified water has been treated to remove contaminants and many dissolved minerals. If your tap water is safe to drink, it is generally fine for formula; purified water becomes the better choice when you have worries about your supply, such as old plumbing, a recent advisory or a taste or smell problem.

When to Boil Water for Formula

Powdered formula is not sterile, and Cronobacter bacteria can occasionally be present in powder. The CDC recommends considering ready-to-feed formula for infants at higher risk, and the WHO recommends mixing powder with water that is hot enough (no cooler than 70°C) to reduce that risk, then cooling the bottle before feeding.

• Bring fresh water to a full rolling boil, following the boiling time given by the CDC or your local health authority.
• Let it cool so it is safe to handle, then mix according to the label and check the temperature on your wrist before feeding.
• Use prepared formula within the time window on the label and discard leftovers after a feed.

If your baby is over 2 months, was born at full term and is healthy, many families mix with safe tap or bottled water without boiling. Ask your pediatrician what is right for your baby.

Fluoride, Well Water and Water Softeners

Fluoride in community water helps protect teeth. Distilled and purified waters usually contain none, so if your baby is mostly formula-fed with these waters, mention it to your pediatrician or dentist. On the other hand, regularly mixing powdered formula with fluoridated water is considered safe, though some babies who get a lot of fluoride can develop mild white spots on their teeth; using low-fluoride bottled water for some bottles is one option your dentist may discuss.

Private wells are not regulated like public supplies and can contain bacteria or nitrates that are especially risky for young babies. Have your well tested regularly and ask your health department before using it for formula.

Never Add Extra Water to Stretch Formula

Whatever water you use, use the exact ratio on the label. Adding more water than directed dilutes calories and nutrients and can disturb a baby's sodium balance, while adding too little can leave them thirsty and stress the kidneys. Ready-to-feed formula is already prepared and needs no water at all. If cost is a worry, ask your pediatrician about assistance programs rather than diluting.

To see how many ml or oz of prepared formula your baby may need, use the formula calculator or read ready-to-feed vs powdered formula. This guide is general information, not individual medical advice.

The Bottom Line

Distilled, purified and safe tap water can all be used for baby formula. Boil and cool the water for young or higher-risk babies, test private well water, keep the powder-to-water ratio exactly as labeled, and talk to your pediatrician about fluoride.