Find information on feeding your infant: human milk, formula and vitamin D.


In the first six months, the best nutrition for your baby is your milk. Visit our breastfeeding/chestfeeding section to learn more.

Mixed feeding (human milk and formula)

For a few parents wanting to breastfeed/chestfeed their baby, supplementing, for personal or medical reasons, may be needed. Your own milk is best for your baby but sometimes donor milk (where available) or formula are needed or chosen.

Sometimes feeding babies away from the breast/chest makes it hard for babies to go back to the breast/chest. It may also decrease your milk supply. Hand expression or pumping each time the baby gets formula will help protect the milk supply.

If you are considering use of a supplement at some point, it is important to first establish breastfeeding/chestfeeding. 

Human milk substitutes

There may be medical or personal reasons for using formula. If you are using formula and/or supplementing your breastfed/chestfed baby with formula, talk to your public health nurse or health care provider.

Formula must be prepared and stored properly to prevent contamination with harmful bacteria. Find instructions and tips:

Have well water tested regularly

If you use well water for drinking, cooking, or preparing infant formula be sure to have your well water tested regularly for bacteria and for chemicals such as nitrates, arsenic and manganese. Find drinking water safety tips for private well owners.

Bottle feeding tips

  • Switch sides with each feed just as you would when feeding at the breast/chest.
  • Spend time skin-to-skin daily with your baby (naked with only a diaper). This improves your baby's development and supports bonding.
  • The goal for responsive bottle feeding is to mimic breastfeeding/chestfeeding as much as possible.
  • Feed your baby holding them close and in an upright position. Use a slow-flow nipple.
  • Allow baby to know the bottle is there by touching the lips with the nipple, inviting a wide-opened mouth/gape. When baby's mouth opens, guide the bottle gently, deep into the mouth with baby’s lips flanged around the base of the nipple.
  • Watch baby’s sucks, tip the bottle up so milk covers the hole in the nipple. The bottle should be nearly horizontal.
  • Often babies will take a rest break. If they stop sucking, tip the bottle down slightly.
  • Continue feeding in response to baby’s cues, always leaving the bottle in baby’s mouth, just as the breast/chest would be. Take time for burps, as needed.

How do I know when baby is hungry or full?

Babies know when they are hungry and how much to eat. Responding to your baby's cues will ensure proper growth and help them develop a healthy relationship with food.

If you are bottle feeding, never force your baby to empty the bottle. Stop offering when you see the signs of fullness such as decreased sucking or turning away from the bottle.

Signs a baby is hungry include becoming upset when the feeding stops, opening their mouth, and wiggling their arms and legs.

If your baby is still hungry after finishing a bottle, offer your baby another bottle of your milk or formula and let them drink until they show signs of fullness.

Do I need to give my baby anything else?

For the first six months, feeding your baby your milk and/or formula, with supplementary vitamin D, is all your baby needs. Introduction of complementary solid foods is not recommended until around six months of age.

Babies do not need additional water or other fluids in the first six months.

Vitamin D

Vitamin D is important for healthy growth and helps to build strong bones and teeth.

  • Babies who are fed human milk or a combination of human milk and formula need 400 IU of a liquid vitamin D supplement every day.
  • Babies who are fed only formula do not need a vitamin D supplement because they will get enough from the formula.

Vitamin D supplements

Choose a liquid vitamin D3 supplement, made from a brand that comes in a dose of 400 IU and has a “NPN” (Natural Product Number). If you are unsure, check with the pharmacist in the store.

Start a daily routine that allows you to remember to give the supplement at the same time each day, for example, before or after a feeding.

Read the label carefully as different brands have different amounts of vitamin D.

If you are using the supplement that is a 1 mL dose (400 IU):

  • Hold your baby in a semi-upright position with head supported.
  • Place dropper between baby’s cheek and the side of your baby’s tongue and squeeze slowly, or place vitamin D on a spoon and let your baby suck it off.

If you are using the supplement that is a single drop (400 IU):

  • Place a drop on nipple or clean finger and let your baby suck it off.
  • It is best not to drop directly into your baby's mouth.

Should I be concerned about allergies?

  • Allergies tend to run in families and can show up as food allergies, eczema, asthma, or hay fever. If your baby, or someone in your family, has allergies, eczema, asthma or hay fever, your baby may have an increased chance of developing food allergies. Speak to a registered dietitian or your family doctor to learn how you can reduce the chance of your baby developing a food allergy.
  • Avoiding certain foods while breastfeeding does not prevent your baby from developing food allergies.
  • Symptoms of food allergies can be mild or severe. Reactions to foods usually happen within minutes of exposure to the food. Find more information on allergy symptoms.

Contact a dietitian

If you have any questions about healthy eating, food, or nutrition, call 8-1-1 to speak to a registered dietitian.