From the moment a mother discovers that she is pregnant, she does her best to eat a healthy diet to ensure that she is giving her baby enough good nutrition. After the baby is born, mothers are encouraged to breastfeed because it is considered the best nutrition she can offer her child. But breast milk tends to be low in a key vitamin that is important for a growing baby’s body – vitamin D. Several studies have measured the amount of vitamin D in breastmilk and they have all shown consistently low levels of vitamin D, even when the mom is taking a supplement that meets the recommended daily dose. Without enough vitamin D a baby is susceptible to getting rickets, which causes a weakening and softening of their bones. This can cause a delay in the growth of the baby and deformities of their bones, such as bowed legs and thickened wrists or ankles. Since babies grow so much during the first year of their life, it is of the upmost importance that they get enough vitamin D during this critical time.

So how do we fix this problem? Is it possible for mothers to boost their own vitamin D level so that they can pass on adequate amounts to their nursing infants?  Or is it more effective to give vitamin D directly to the baby?  There are two thoughts on this issue. The first is that the baby should only receive their mother’s breast milk and it is up to the mother to increase her own vitamin D levels so that her baby gets enough. The second is that it is either too difficult or not possible for a mother to increase her own vitamin D levels sufficiently and the baby has a better chance of getting optimal vitamin D levels if they receive vitamin D directly. So who is right? Both are.

Is it possible for a breastfeeding mom to increase her own vitamin D levels so that she can pass on enough vitamin D to her baby? Absolutely! But in order to this the mom needs to take 4,000 to 6,400 IU of vitamin D per day every day.1  To put this in perspective, prenatal vitamins typically contain only 400 IU, which is significantly lower than this amount.11 Women can get some vitamin D from foods such as fortified milk, fatty fish, fish liver oil, and egg yolks but these foods tend to be consumed in small amounts. The sun is also a source of vitamin D but many factors will influence how much vitamin D can be absorbed. These factors are things such as how far north you live, what time of year it is, how much time you spend outside without sunscreen, and the darkness of your skin.12 Ultimately, the most reliable way to boost vitamin D levels is by taking a supplement using a standalone vitamin D product.

The vitamin D recommendation for adults living in North America ranges from 600 IU to 4000 IU per day. 2,3,4  Most experts agree that supplemental vitamin D is safe in amounts up to 4,000 international units per day during pregnancy or breastfeeding.11 But there currently isn’t enough safety information to recommend taking doses higher than 4,000 IU per day. Although it is rare, there are certain risks that can occur when taking a vitamin dose that is too large. 1 Therefore, any breastfeeding women who is thinking about taking more than 4,000 IU of vitamin D per day should talk to their healthcare providers before taking it.

The recommendations for pregnant women living in the UK are slightly different. These women should take a daily dose of 10 micrograms (µg) (400 IU) of vitamin D during pregnancy and breastfeeding.5 However, some women may need more than this amount and include women who have limited sun exposure, have darker pigmented skin, or have a higher pre-pregnancy BMI.6

So what should a mom do when she either can’t or doesn’t want to take large amounts of vitamin D supplements? The best and safest option is to give the baby a daily supplement of vitamin D. The American Academy of Pediatrics, Health Canada and the Canadian Pediatric Society all recommend that exclusively breastfed, healthy, term infants should receive 400 IU of vitamin D per day.7,8,9 The Canadian Paediatric Society recommends that babies who live in northern Native communities should get 800 IU vitamin D per day during the winter months.10

Natalie Bourré is a Ddrops Guest Blogger. She is a mom of 4 young children, health writer  and social media consultant who is passionate about promoting good health for the entire family. She is keen to share scientific information about about vitamin D in an easy to understand fashion. She also truly listens to people’s input and as such, she welcomes you to connect, discuss and share your questions and feedback with her on our social media accounts.  

Updates and edits by Carrie Noriega, MD, FACOG.

  1. Adekunle Dawodu and Reginald C. Tsang. Maternal Vitamin D Status: Effect on Milk Vitamin D Content and Vitamin D Status of Breastfeeding Infants. 2012 American Society for Nutrition. Adv. Nutr. 3: 353–361, 2012; doi:10.3945/an.111.000950.
  2. Health Canada, Vitamin D and Calcium: Updated Dietary Reference Intakes,
  3. Institute of Medicine,Dietary Reference Intakes for Calcium and Vitamin D, 2011
  4. John C Godel, Canadian Paediatric Society ,First Nations, Inuit and Métis Health Committee, “Vitamin D supplementation: Recommendations for Canadian mothers and infants”, Paediatr Child Health 2007;12(7):583-9,
  5. Chief Medical Officers for the United Kingdom.Vitamin D – advice on supplements for at risk groups. Cardiff, Belfast, Edinburgh, London: Welsh Government, Department of Health, Social Services and Public Safety, The Scottish Government, Department of Health; 2012 [].
  6. Royal College of Obstetricians and Gynaecologists. Vitamin D in Pregnancy. Scientific Impact Paper No. 43 June 2014
  7. American Academy of Pediatrics, Vitamin D Supplementation for Infants, 3/22/2010,
  8. Health Canada. Vitamin D supplementation for breastfed infants – 2004 Health Canada recommendation.
  9. Canadian Paediatric Society, POSITION STATEMENT: Vitamin D supplementation: Recommendations for Canadian mothers and infants, January 30 2015.
  10. Canadian Paediatric Society, First Nations and Inuit Health Committee [Principal author: J Godel]. Vitamin D supplementation in northern Native communities. Paediatr Child Health 2002;7:459-63.
  11. Vitamin D: Screening and Supplementation During Pregnancy. American College of Obstetrics and Gynecology. Committee Opinion Number 495, July 2011 reaffirmed 2015.
  12. Institute of Medicine of the National Academies (US). Dietary reference intakes for calcium and vitamin D. Washington, DC: National Academy Press; 2010.