Vitamin D; What breastfeeding mamas need to know


Guest post by Doria K. Thiele, PhD, CNM, IBCLC, a Nurse Midwife, Lactation Consultant and founder of the Portland Lactation Center, LLC.

vitamin D in breastmilk by Alavita & Portland Lactation Center

You may need to take extra vitamin D while breastfeeding.

why you and your baby need vitamin D

Vitamin D in your bloodstream tells your intestine to absorb more calcium and phosphate, therefore playing a critical role in bone structure & strength. Recent research has demonstrated that vitamin D also plays a role in prevention of some cancers (colon in particular), autoimmune diseases (Type I diabetes, multiple sclerosis), and is important in maximizing ovarian function and improving fertility. 

So why would breast milk be lacking in such a critical component? 


all about your breast milk

Breast milk is a compilation of hundreds of components that meet the specific needs of your baby, but it can fall short, depending on your diet and lifestyle. 

I remember way back in the day (circa 2000) when I was first training to be a midwife, we learned that even if moms were lacking in nutrients, the baby would still get everything they need. We now know differently. We now know that a nursing mama needs a healthy diet to meet her own body’s needs and the needs of her baby. 


Why you are likely low in vitamin D

Fun Fact: Vitamin D is actually a hormone and has been misnamed a 'vitamin' since it was first discovered.

Vitamin D, or hormone D, if you will, is photosynthesized in your skin when exposed to sunlight. A vast majority of adults and children in the U.S. spend most daylight hours inside. This lack of sun exposure leaves most of us vitamin D deficient. If a breastfeeding mama has low vitamin D levels in her blood, then her breast milk will also be low in vitamin D. The more pigment you have in your skin, the more time you need in the sun to produce sufficient vitamin D. Therefore, women of color are at even higher risk of vitamin D deficiency.


What you can do 

  1. Have your serum vitamin D level checked with a test called 25-Hydroxy-Vitamin D (25[OH]D). You want your levels in the normal range (30-40ng/mL).

  2. If your serum 25(OH)D levels are below the normal range, take 5000 IU of vitamin D daily prior to, during, and/or after pregnancy.*

  3. Be sure to choose a reputable brand that carries a variety of dosing options, such as Thorne.

Note: The vitamin D in your prenatal vitamin is likely not enough. Most prenatal vitamins contain 400-800 IU of vitamin D, so these should not be considered an adequate source of this nutrient.

Second Note: Unfortunately, sunscreen blocks vitamin D synthesis. So get outside! But protect your skin and don't rely on those rays for your vitamin D. 

*Always talk to your primary health care provider first before starting a vitamin regimen. 


Doria Thiele.jpg


Doria Thiele, PhD, CNM, IBCLC is the founder of Portland Lactation Center, LLC and the proud mama of two kiddos!  She offers compassionate care to help you build a breastfeeding plan that will work for your family.