Researchers studied breast milk from over 1,200 healthy mothers in four countries to measure important fat-soluble vitamins (A, E, and D) that babies need. They found that breast milk contains good amounts of vitamins A and E, but falls short on vitamin D—babies only get about 6% of the vitamin D they need from breast milk alone. This large international study provides the most accurate picture yet of what nutrients babies actually receive through breastfeeding, helping doctors and health organizations better understand infant nutrition and make better recommendations for mothers and babies.

The Quick Take

  • What they studied: How much of three important vitamins (A, E, and D) are actually found in breast milk throughout the first 8.5 months of breastfeeding
  • Who participated: 1,242 healthy mothers from Bangladesh, Brazil, Denmark, and The Gambia who were breastfeeding. Researchers collected milk samples multiple times during the first 8.5 months to track how vitamin levels changed over time
  • Key finding: Breast milk provides nearly all the vitamin A babies need (97%), about three-quarters of the vitamin E they need (75%), but only about 6% of the vitamin D they need. Vitamin D levels were much lower than previously thought
  • What it means for you: If you’re breastfeeding, your milk is doing a great job with vitamins A and E, but babies will need vitamin D from other sources like supplements or fortified foods. Talk to your pediatrician about vitamin D drops for your baby

The Research Details

This was a large international study that collected breast milk samples from mothers in four different countries over an 8.5-month period. The researchers measured milk samples at multiple time points to see how vitamin levels changed as babies grew. They used specialized laboratory equipment (high-performance liquid chromatography and mass spectrometry) to accurately measure tiny amounts of vitamins A, E, and D in the milk samples.

The study included only well-nourished mothers to focus on what healthy, well-fed women naturally produce in their milk. By studying mothers from different countries with different diets and environments, the researchers could see if vitamin levels stayed consistent or varied based on geography and lifestyle.

The researchers then compared their findings to the standards set by the Institute of Medicine, which are used to determine how much of each nutrient babies should get daily.

This research approach is important because it provides real-world data about what’s actually in breast milk, rather than relying on older estimates or assumptions. By collecting samples over time from the same mothers, researchers could track how vitamin levels naturally change as lactation progresses. Testing milk from mothers in different parts of the world helps us understand whether breast milk composition is similar everywhere or varies by region and diet

This study is reliable because it included a large number of mothers (1,242) from multiple countries, making the results more representative of global breastfeeding populations. The researchers used precise laboratory methods to measure vitamins accurately. However, the study only included well-nourished mothers, so results may not apply to mothers with poor nutrition or vitamin deficiencies

What the Results Show

The study found that breast milk vitamin levels vary depending on which vitamin you’re looking at. For vitamin A (retinol), breast milk from these mothers matched what health organizations expected, except in the very first weeks when levels were actually higher than expected. This is good news because it means babies get adequate vitamin A from breastfeeding.

For vitamin E (alpha-tocopherol), breast milk contained about 76% of what health organizations recommend babies receive. This is still a substantial amount, but suggests that babies might benefit from additional vitamin E from other foods as they start eating solid foods. The researchers also measured gamma-tocopherol (another form of vitamin E) for the first time in this type of study, finding an average of 0.89 mg per liter.

Vitamin D told a different story. Breast milk contained only 60-80% of what the Institute of Medicine estimated, which is already known to be insufficient. This means babies are only getting about 6% of their daily vitamin D needs from breast milk alone. This finding confirms that vitamin D supplementation is essential for breastfed babies, especially in regions with limited sun exposure.

When researchers calculated total daily vitamin intake for babies aged 1-6 months based on typical milk consumption, they found that babies get 97% of their vitamin A needs, 75% of their vitamin E needs, and only 6% of their vitamin D needs from breast milk. This shows that while breast milk is excellent for vitamins A and E, it cannot be the only source of vitamin D for infants. The study also provided detailed percentile curves showing the range of vitamin levels found across different mothers, which helps other researchers interpret their own findings

This research updates and refines previous estimates of breast milk vitamin content. The vitamin A findings align well with older data, confirming that breast milk is a reliable source of this nutrient. However, the vitamin E levels were lower than previously estimated by the Institute of Medicine, suggesting that older recommendations may have overestimated what’s actually in breast milk. Most importantly, the vitamin D findings confirm what many pediatricians already knew—that breast milk alone doesn’t provide enough vitamin D, and supplementation is necessary

The study only included healthy, well-nourished mothers, so results may not apply to mothers with malnutrition or vitamin deficiencies. The mothers studied were from specific regions, so vitamin levels might differ in other parts of the world with different diets and sun exposure. The study measured vitamins at specific time points but didn’t track individual mothers’ vitamin levels over the entire 8.5-month period, so some variation between mothers may not have been captured

The Bottom Line

Breastfeeding mothers should feel confident that their milk provides excellent amounts of vitamins A and E for their babies. However, all breastfed babies should receive vitamin D supplementation (typically 400 IU daily) starting in the first few weeks of life, as recommended by pediatricians. This recommendation is supported by strong evidence and is standard medical practice. Mothers can discuss vitamin D drops with their pediatrician to ensure their baby receives adequate vitamin D

This research is important for breastfeeding mothers, pediatricians, lactation consultants, and public health organizations. Parents considering breastfeeding should know that while breast milk is nutritionally excellent, vitamin D supplementation is a necessary addition. Healthcare providers can use this information to make evidence-based recommendations. This is less relevant for formula-feeding families, as infant formulas are fortified with appropriate vitamin levels

Vitamin D supplementation should begin in the first few weeks of life and continue throughout infancy and early childhood. The benefits of adequate vitamin D develop over weeks and months as the vitamin accumulates in the body and supports bone development and immune function. Parents should not expect immediate visible changes but should view supplementation as essential long-term support for healthy development

Want to Apply This Research?

  • Track daily vitamin D supplementation for your breastfed baby by logging the date, time, and dose of vitamin D drops given. Note any changes in feeding patterns or baby’s health status to discuss with your pediatrician
  • Set a daily reminder to give your baby vitamin D drops at the same time each day (such as during the first morning feeding). Store the vitamin D bottle in a visible location near where you typically breastfeed to make it part of your routine
  • Monitor your baby’s vitamin D status by keeping records of supplementation compliance and discussing blood vitamin D levels with your pediatrician at regular check-ups. Track any signs of vitamin D deficiency (such as delayed bone development) and adjust supplementation as recommended by your healthcare provider

This research provides important information about breast milk composition but should not replace personalized medical advice from your pediatrician. All breastfed infants should receive vitamin D supplementation as recommended by their healthcare provider. If you have concerns about your baby’s nutrition or your breast milk composition, consult with your pediatrician or a lactation specialist. This information is for educational purposes and does not constitute medical advice