How to Feed a Baby Breast Milk During the Day and Formula at Night

Although the American Academy of Pediatrics recommends exclusive breastfeeding until a baby is at least six months old, supplementing with formula also has benefits. Breastfeeding during the day and bottle-feeding at night allows you to get more sleep since it lets your partner participate more in feeding your infant. Babies who receive enough formula at night also may not require the vitamin D supplementation like infants who are exclusively breastfed. If you have any specific questions or concerns about the process, contact your doctor or lactation consultant for advice.

Wait until your breast milk is established before supplementing with formula. Wait until your baby is 1 month old to help avoid nipple confusion because the sucking actions required during breastfeeding and bottle-feeding are different, explains KidsHealth.

Purchase a formula that is appropriate for your infant. Most infants do well with a formula based on cow's milk that contains DHA and iron, but infants with a milk allergy or sensitivity may require a formula made from soy. Ask your health care practitioner if you are unsure which type to use.

Prepare the bottle of formula by following the label on the package. The specific preparation depends on whether you use powder, liquid or ready-to-feed formula. Bottles made with formula stay fresh for up to 24 hours under refrigeration.

Find someone else to feed the baby the bottles of formula at night, if possible. Minimize the likelihood of your baby wanting you to give her a bottle instead of your breast during the day by letting her believe you only provide milk while others only provide formula, suggests KidsHealth.

Offer your baby the bottle of formula at night instead of your breast. If your baby typically eats several times throughout the night, replace one of the feedings at a time and gradually move toward having all the nighttime feedings from formula.

Express your milk at night. If you would like to minimize your milk production at night, express just enough to prevent you from feeling engorged or uncomfortable. If you would like to encourage your body to keep producing milk throughout the night even though you aren't nursing, use a breast pump and save the milk you collect for daytime use.


Babies who are breast fed require a vitamin D supplement of 400 IU a day, even if they are getting a few bottles of formula a day. However, if your baby gets at least 32 oz. of formula in a 24-hour period, she no longer needs a vitamin D supplement.


If your baby develops diarrhea, vomiting, scaly or red skin, extreme fatigue, or weakness after consuming formula, call a doctor. This may be sign of an allergy to the formula.