Quick answer
LactMed says maternal vitamin D of 10 to 50 mcg a day gives milk levels too low to meet an exclusively breastfed infant's needs, and doses up to 160 mcg were not tied to short-term infant lab abnormalities. NIH's upper limit while breastfeeding is 100 mcg. Ask your doctor about your dose and your baby's supplement.1,2
Key facts
- LactMed says a mother taking 10 to 50 mcg (400 to 2,000 IU) of vitamin D a day makes milk that cannot deliver the infant's daily requirement, so the infant still needs a supplement of at least 10 mcg (400 IU).1
- Maternal doses of 10 to 160 mcg (400 to 6,400 IU) a day were not tied to short-term lab abnormalities in breastfed infants, according to LactMed.1
- LactMed reports one newborn with mild high blood calcium whose mother took 100,000 IU a day of prescribed vitamin D2 after surgery on her thyroid and parathyroid glands.1
- The American Academy of Pediatrics recommends 10 mcg (400 IU) a day for breastfed infants from shortly after birth, NIH reports.2
- NIH's upper limit for pregnant and breastfeeding teens and women is 100 mcg (4,000 IU) a day from all sources.2,3
What LactMed says about vitamin D and breast milk
LactMed, the National Library of Medicine's database for nursing mothers, starts with the basics: vitamin D is a normal component of human milk. A mother's daily supplement of 10 to 50 mcg (400 to 2,000 IU) produces milk levels that are too low to deliver an exclusively breastfed infant's daily requirement, and too low to correct an infant's existing low vitamin D through breastfeeding alone.1
For that reason LactMed says breastfeeding mothers who take supplements in this range should still give their infants a daily vitamin D supplement of at least 10 mcg (400 IU), to meet pediatric nutritional guidelines. At 100 mcg (4,000 IU) a day or more, milk levels can potentially meet the infant's goal, depending on the mother's own status and on how much milk the infant takes.1
What LactMed reports about infants
- Maternal daily doses of 400 to 6,400 IU (10 to 160 mcg) were not associated with short-term lab abnormalities in breastfed infants.1
- An 11-day-old, exclusively breastfed girl had mild high blood calcium. Her mother took 100,000 IU a day of vitamin D2 as treatment after thyroid and parathyroid surgery, on top of a prenatal vitamin, and her cord blood and milk levels were markedly high. The infant's own blood level was not measured.1
- In randomized trials of mothers given single or repeated high doses, such as 6,000 IU, 6,400 IU a day or 120,000 IU every few weeks, infants' calcium, growth and bone measures were similar to those of infants whose mothers took less or none. In several of these trials the comparison infants received their own daily vitamin D supplement.1
- In a trial of 1,300 pregnant women in Bangladesh whose treatment continued after birth in some groups, infant high calcium was rare (1% or less) and did not differ between groups.1
What NIH says about amounts and the infant's own supplement
Breast milk alone does not give a baby enough vitamin D. Mothers who take at least 50 mcg (2,000 IU) of vitamin D3 a day appear to have more vitamin D in their breast milk.2,3
NIH's health professional sheet reports that the American Academy of Pediatrics recommends 10 mcg (400 IU) a day of vitamin D for exclusively and partially breastfed infants, starting shortly after birth. It also says prolonged exclusive breastfeeding without vitamin D supplementation can cause rickets in infants.2
For the mother, NIH's recommended amount while breastfeeding is 15 mcg (600 IU) a day and its upper limit is 100 mcg (4,000 IU) a day from all sources. Some of the trial doses listed above go beyond that limit. They are research findings, and this page gives no dose advice.1,3
Who should ask their doctor
Ask your doctor or your baby's pediatrician about the infant's own vitamin D, and about your supplement if you take more than a prenatal vitamin provides. Ask especially if you have been prescribed high-dose vitamin D, have a condition that affects calcium, kidney disease or a history of kidney stones, or take a thiazide diuretic, a statin or steroid tablets.2,3
Questions people ask
Is vitamin D3 safe while breastfeeding?
LactMed covers vitamin D2 and D3 together. It reports that maternal doses of 10 to 160 mcg a day were not tied to short-term lab abnormalities in infants. Ask your doctor what suits your situation.1
Is vitamin D safe in breastfeeding when the baby also takes drops?
NIH counts vitamin D from all sources against the upper limits, and the mother's and the infant's limits are separate. LactMed says infants of mothers taking 10 to 50 mcg a day still need their own supplement.1,2
Is a vitamin D supplement safe while breastfeeding at 4,000 IU?
4,000 IU (100 mcg) a day is NIH's upper limit for breastfeeding women, and LactMed says doses at or above it can potentially meet the infant's goal. Ask your doctor before using a dose near the limit.1,2
Does breast milk have enough vitamin D?
NIH says breast milk alone does not give a baby enough vitamin D, and recommends a supplement of 10 mcg (400 IU) a day for breastfed infants. Ask your pediatrician.2
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Sources
- Vitamin D. In: Drugs and Lactation Database (LactMed). Bethesda (MD): National Institute of Child Health and Human Development; 2006-. Record read October 2026 through PubChem's copy of the LactMed text, because NCBI Bookshelf blocks scripts. Opened 2026-10-11.
- National Institutes of Health, Office of Dietary Supplements. Vitamin D: Fact Sheet for Health Professionals. Updated June 27, 2025. Opened 2026-10-07.
- Office of Dietary Supplements, National Institutes of Health. Vitamin D: Fact Sheet for Consumers. Updated November 8, 2022. Opened 2026-10-07.
This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.