Breast milk is the best food for your baby, but it doesn’t have enough vitamin D. The CDC, the American Academy of Pediatrics, and the Dietary Guidelines for Americans all recommend a daily vitamin D supplement for breastfed babies, starting in the first few days of life.

The short version

  • The amount: 400 IU (10 micrograms) of vitamin D a day for breastfed and partially breastfed babies, according to the CDC.
  • When to start: in the first few days of life, not at 2 or 4 months.
  • Why: breast milk alone doesn’t provide enough, and sunshine isn’t a reliable source for a baby.
  • Partly breastfed babies need it too, if they drink less than 32 ounces of formula a day.
  • It’s a liquid. Ask your pediatrician which product to use and how to give it.
  • Your own vitamin D matters as well. See Vitamin D in Pregnancy.

Why breastfed babies need drops

Vitamin D helps build healthy bones and prevents rickets, a condition that causes weak or deformed bones, according to the CDC. Breast milk alone doesn’t give babies enough of it. Sunlight can make vitamin D in the skin, but how much a baby gets varies, and sun exposure raises the risk of skin cancer, so the CDC recommends a supplement instead of relying on the sun.

Ask about vitamin D at your baby’s first checkup, so the drops start in the first few days of life instead of later.

Does your baby need drops?

How your baby is fed Vitamin D drops?
Only breast milk Yes: 400 IU a day, starting in the first few days
Breast milk plus some formula, with less than 32 ounces of formula a day Yes: 400 IU a day
Formula, with 32 ounces or more a day Usually no, because infant formula is made to give 400 IU in about 32 ounces
Formula, with less than 32 ounces a day Ask your pediatrician
After 12 months 600 IU a day from food, such as fortified milk, or a supplement if your pediatrician recommends one

The 32-ounce line comes from the CDC for partially breastfed babies. The rest follows the American Academy of Pediatrics guidance, and your pediatrician can tell you where your baby falls, especially in the first months when formula amounts are small.

How much, and how to give it

The dose is 400 IU a day. That’s the amount the CDC, the American Academy of Pediatrics, and the Dietary Guidelines recommend for breastfed and partially breastfed babies.

Check the label. Liquid vitamin D products don’t all work the same way. Some give 400 IU in a single drop, and others give it in half a milliliter or a full milliliter. Use only the dropper that comes with your product, follow the label’s dose, and ask your pediatrician which product to buy.

Don’t go above the upper limit. For babies, the upper limit from all sources is 1,000 IU a day from birth to 6 months and 1,500 IU a day from 7 to 12 months, according to MedlinePlus. Too much vitamin D makes the body absorb too much calcium, which can cause nausea, vomiting, constipation, weakness, and kidney problems. Toxicity almost always comes from supplements, so measure carefully.

Ask about iron too. The American Academy of Pediatrics has recommended iron drops for breastfed babies starting at 4 months, and the CDC advises asking your baby’s provider. Ask your pediatrician whether one product can cover both. See Iron for Breastfed Babies.

Store it safely. Keep vitamin D drops, like any supplement, out of children’s reach.

When the drops stop

Your pediatrician will tell you when to stop. In general, drops continue as long as your baby is breastfed or drinking less than 32 ounces of formula a day. After the first birthday, your child’s vitamin D comes from fortified milk and other foods, or from a supplement if the pediatrician recommends one. The daily amount rises to 600 IU, according to MedlinePlus.

What to do now

  • At your baby’s first checkup, ask which vitamin D product to use and how much to give.
  • Start in the first few days of life.
  • Read the label to see how much liquid gives 400 IU.
  • Keep the bottle out of reach.
  • Keep your own vitamin D up while you breastfeed. See Vitamin D Supplements in Pregnancy.

Related reading

Sources

  • Vitamin D and Breastfeeding, Centers for Disease Control and Prevention (amount, timing, 32-ounce rule, why breast milk isn’t enough)
  • Vitamin D, MedlinePlus Medical Encyclopedia, National Library of Medicine, reviewed January 2025 (upper limits, side effects, amount after age 1)

Updated November 2026. This article is for general information and is not a substitute for advice from your baby’s health care provider.