Does your breastfed baby really need vitamin D supplements?


At your baby’s first well check, your pediatrician will likely recommend you to start giving your exclusively breastfed baby a vitamin D supplement (formula is already fortified with the vitamin so if you’re supplementing or using formula exclusively you don’t need to worry). The pediatrician may prescribe you a little dropper bottle or give you a few recommendations to take home and find on your own.

When I had my first nearly 7 years ago (where has the time gone!), I had no idea why (the doctor didn’t tell me) he needed a supplement when breast milk was supposed to be the “perfect” food. The pediatrician prescribed us some vitamin D and I dutifully picked it up from the pharmacy. I had such a difficult time wrapping my brain around WHY my perfect, brand new baby would need medicine right from the get-go. The little bottle was never opened and for the next 3 babies, I didn’t bother to pick-up my prescription. Upon entering graduate school to study nutrition, I was bombarded with research on the importance of vitamin D in our bodies - especially infants.

Vitamin D maintains the health of bones and teeth, supports a healthy immune system, regulates insulin levels, and supports lung and heart health (just to name a few). On top of that, more that HALF of the population in the United States is deficient in vitamin D. Not just a little - but more than half of Americans aren’t even getting close to the recommended amount (400–800 IU/day). And common research reveals that vitamin D doesn’t pass through breastmilk from mother to baby so the ‘only way’ for exclusively breastfed babies to get the recommended amounts of vitamin D is through a supplement.

Fortunately, that’s not really the case anymore.


There’s been research in recent years that pretty handily debunks the myth that vitamin D doesn’t transfer to breastmilk from mamas.

Two recent studies show that if a mother is consuming at least 4000 IU of the vitamin daily, then the infant will likely receive enough to meet recommendations. Another study reported that maternal intakes of 6400 IU daily was enough to get adequate amounts to baby through breastmilk exclusively. AND it doesn’t mean that the vitamin is just passing from you to baby - these studies show that not only does baby get enough vitamin D, but mama does as well (articles linked at the bottom of the page).

So WHY then, is the common recommendation to supplement breastmilk with a chemical version of vitamin D? Because we are spending more and more time indoors and wearing more and more sunscreen and, we as mothers aren’t getting anywhere near the recommended amounts of vitamin D in our daily lives so there isn’t any to pass on through breastmilk to our babies.



But honestly, it’s not hard at all to get enough vitamin D.

Just 10-15 minutes out in the sun a few times a week without gobs of sunscreen will get you enough vitamin D. You can slather your sunscreen on later, but get some real UV exposure first (I like this sunscreen). To get enough to pass on through breastmilk, you’ll want to look at increasing dietary vitamin D as well. Aside from sunshine, other great sources of vitamin D are:

dairy products
mushrooms (that have been exposed to UV light - most commercial mushrooms are grown in the dark - look for ‘wild’)
fortified tofu

**With many vitamins (or anything we do, use, etc), there are risks of consuming too much. Vitamin d toxicity is one of the ones to really look out for. Too much vitamin D can cause a buildup of calcium in the bones that can lead to nausea, vomiting, weakness and frequent urination. Before you begin any supplement regimen or drastically change your diet or sun exposure, you should consult a nutritionist, doctor or other healthcare professional.

Not sure you’re getting enough vitamin D? I’m always available for consults. You’re welcome to email me at to set up a consultation or use the button below to contact me and set one up.


Hollis, B. W., & Wagner, C. L. (2004, December). Vitamin D requirements during lactation: High-dose maternal supplementation as therapy to prevent hypovitaminosis D for both the mother and the nursing infant. Retrieved from

Hollis, B. W., Wagner, C. L., Howard, C. R., Ebeling, M., Shary, J. R., Smith, P. G., . . . Hulsey, T. C. (2015, October). Maternal Versus Infant Vitamin D Supplementation During Lactation: A Randomized Controlled Trial. Retrieved from