Vitamin D & Breastfeeding – How Much Do You Really Need?

If you’re breastfeeding and wondering whether you’re getting (or giving) enough vitamin D, you’re not alone. Vitamin D & breastfeeding is one of those topics that rarely comes up in doctor visits but quietly plays a big role in your baby’s health—and yours too.

Is Breast Milk Low in Vitamin D—and Why?

Here’s the short version: breast milk doesn’t usually contain enough vitamin D to meet your baby’s needs. Vitamin D levels in breast milk range from about 20 to 60 IU per liter. That’s far below what your baby needs to grow strong and stay healthy.

Breast milk is usually low in vitamin D because most modern moms don’t get enough sun. Our bodies make vitamin D from sunlight, but indoor lifestyles, sunscreen use, and limited dietary sources mean many mothers are deficient—so their milk is too. It’s not a flaw in breast milk; it’s a reflection of how we live today.

Why Vitamin D Matters For Breastfed Babies

Vitamin D helps your baby’s body absorb calcium and build strong bones. Without enough of it, babies can develop rickets—a condition that softens bones and can lead to serious problems.

That’s why health organizations like the CDC and American Academy of Pediatrics recommend that all breastfed babies get 400 IU (International Units) of vitamin D every day, starting soon after birth.

What About You? Do Breastfeeding Moms Need Vitamin D Too?

Yes—and not just for your baby. Your body uses vitamin D to keep your bones strong, support your immune system, and even regulate mood.

While you’re breastfeeding, your body needs more vitamin D than usual. But here’s the catch: if your vitamin D levels are low (and many moms’ are, especially if you have darker skin, cover up outdoors, or live in a less sunny place), your milk probably won’t carry enough to meet your baby’s needs.

Most prenatal vitamins include around 400–600 IU of vitamin D, which is well below the 4,000–6,400 IU/day shown in research to raise vitamin D levels in breast milk to meet infant needs.

Two Ways To Get Baby Enough Vitamin D

You’ve got two solid options:

1. Give your baby a daily supplement with 400 IU of vitamin D. This is the standard recommendation and widely available over the counter. It’s easy to find drops that go right into baby’s mouth or even on your nipple before nursing.
2. Take a higher dose yourself. Some studies show that if a breastfeeding mom takes 6,400 IU of vitamin D per day, her milk can provide enough for her baby—without a separate supplement. But not every doctor will recommend this yet, so talk to your healthcare provider before trying it.

Either way works. The best choice is the one you’ll actually stick with.

Is High-Dose Vitamin D Safe For Moms?

Short answer: Yes, for most people.

Research shows that doses up to 6,400 IU/day of Vitamin D are safe during breastfeeding and don’t cause harmful levels in moms or babies. That said, it’s always smart to check with your provider before making big changes—especially if you’re taking other medications or have any health conditions.

If you go this route, be consistent. Vitamin D is fat-soluble, meaning your body stores it, but regular daily intake is key to keeping your levels up.

What About Sun Exposure?

Sunlight helps your skin make vitamin D, but how much you get depends on a bunch of things: the time of year, your skin tone, where you live, and how much skin you expose.

If you have darker skin, you naturally produce less vitamin D from the same amount of sun. And if you’re mostly indoors, cover up for cultural or personal reasons, or live somewhere with long winters—you probably can’t rely on sunlight alone.

A few minutes of sun exposure can help. Aim for 4–5 minutes a day with baby in just a diaper or naked, if it’s safe and warm enough. Skip the sunscreen during that time so the skin can absorb sunlight, but don’t let baby stay out long enough to get pink or irritated. Black babies may need up to double the time for the same effect.

Still, even with some sun, most breastfeeding moms and babies need a Vitamin D supplement.

Why Take Extra Vitamin D?

Here’s what vitamin D can do for both you and your baby:

• Supports strong bones and teeth
• Helps prevent rickets and other bone diseases like osteomalacia
• Strengthens the immune system
• May reduce long-term risk of conditions like multiple sclerosis, rheumatoid arthritis, and some cancers
• Supports mood and mental well-being
• Lowers risk of osteoporosis later in life
• Research even suggests vitamin D supplementation during infancy may reduce the risk of type 1 diabetes by up to 90%
• Postpartum hair loss – Vitamin D won’t prevent all postpartum shedding (since that’s largely hormonal), but it’s essential for healthy hair regrowth and could help shorten the shedding phase or reduce severity—especially if you’re deficient.

How Much Vitamin D Is Enough?

• Babies: Aim for 400 IU daily via supplement. The minimum effective dose is 200 IU, but 400 IU is widely recommended.
• Moms: If you’re relying on your milk to meet your baby’s needs, studies support taking 6,400 IU daily. If you’re supplementing baby directly, a daily dose of 1,000 IU for yourself is often enough to maintain your own health.

If you’re getting some sun and eating vitamin D-rich foods, that helps too. Some families use a combo approach: sun exposure in the summer, then supplements in the winter.

Who’s At Higher Risk Of Vitamin D Deficiency?

You may be more likely to have low vitamin D if:

• You have dark skin
• You stay indoors most of the time
• You cover most of your skin with clothing or veils
• You avoid the sun during pregnancy or postpartum
• You’re malnourished or have limited access to nutrient-rich foods

If that sounds like you, it’s especially important to ask your provider about testing and supplement options.

The Bottom Line On Vitamin D & Breastfeeding

You don’t have to know everything about vitamin D to make a smart choice—you just need the basics:

• Babies need 400 IU of vitamin D a day.
• Breast milk alone doesn’t provide enough.
• You can either supplement your baby—or boost your own intake.

Whichever path fits your life best is the right one. And if you ever feel unsure, talk to your provider. You’ve got options—and you’re not in this alone.

Resources

• Find a breastfeeding support group near you.
• Milkology Breastfeeding Class – Affordable, video-based online course to help you master breastfeeding at your own pace.

References

• Maternal vs. Infant Vitamin D Supplementation During Lactation — Pediatrics, American Academy of Pediatrics (2015). This randomized controlled trial showed that a maternal dose of 6,400 IU/day of vitamin D was as effective as direct infant supplementation in maintaining adequate infant vitamin D levels.
• Vitamin D — LactMed® (Drugs and Lactation Database) — NCBI Bookshelf, U.S. National Library of Medicine (2024). This database summarizes the evidence on vitamin D levels in breast milk, safe maternal dosing, and the potential for infant sufficiency through maternal supplementation.
• Calcium, Zinc and Vitamin D in Breast Milk: A Systematic Review and Meta-Analysis — International Breastfeeding Journal (2023). This systematic review provides hard data on the typical vitamin D content in breast milk (20–60 IU/L), underscoring why supplementation is needed.