Vitamin D and your baby

Vitamin D helps our bodies use calcium to build and maintain strong bones and teeth.

Low levels of vitamin D in babies/children can cause rickets. Rickets can result in weak bones, delayed walking, bowed legs, and swollen wrists or ankles. If untreated, rickets can lead to failure to grow, deformed or broken bones, pneumonia and seizures.

Every year a number of babies/children in New Zealand are diagnosed with rickets.

Sources of vitamin D

Vitamin D is known as the ‘sunshine vitamin’ because our bodies can make it from the sun. When the skin is exposed to sunlight, the ultraviolet B (UVB) rays from the sun are used to make vitamin D.

However, babies can’t safely get the vitamin D they need from the sun. Their skin is very sensitive and should not be exposed to direct sunlight.

Breast milk is the ideal and recommended food for your baby but it is not a good source of vitamin D.

High risk

  • If your baby is breastfed and:
    • has naturally dark skin
    • you have been told that you are low in vitamin D
    • one or more of your children has had rickets or seizures resulting from low blood calcium levels
    then they are at high risk of vitamin D deficiency.
  • Babies who are born preterm with low body weight may be vitamin D deficient.
  • Babies who are breastfed over winter months in New Zealand may also be vitamin D deficient by late winter/spring.

Supplements for babies at risk of deficiency

If your baby is at high risk of vitamin D deficiency, talk to a health professional such as your doctor, midwife or dietitian. Your doctor can prescribe a vitamin D supplement that comes in drops.

Drops can either be:

  • put on your nipple before your baby latches on
  • given directly into your baby’s mouth using a dropper.


Vitamin D and Your Pregnancy / Vitamin D and Your Baby
This factsheet is available in several languages.

Back to top