Is vitamin E (α‑tocopherol) secreted into human breast milk?

Vitamin E Secretion in Human Breast Milk

Yes, vitamin E (α-tocopherol) is actively secreted into human breast milk, with concentrations that vary significantly by stage of lactation and maternal nutritional status.

Vitamin E Content Across Lactation Stages

The concentration of α-tocopherol in breast milk decreases substantially as lactation progresses 1, 2:

• Colostrum (days 2-4): Contains the highest levels at approximately 40.5 µmol/L (9.99 mg/L), providing an estimated 6.2 mg/day to the infant 1, 2
• Transitional milk (day 14): Drops to approximately 13.9 µmol/L, providing 4.7 mg/day 1
• Mature milk (day 30-90): Further decreases to 8.0 µmol/L (2.07 mg/L), providing only 2.7 mg/day 1, 2

This progressive decline means that only colostrum and transitional milk reliably meet the infant's nutritional requirement of 4 mg/day of vitamin E, while mature milk may provide inadequate amounts 1.

Maternal Factors Affecting Milk Vitamin E Content

Dietary Intake and Supplementation

Maternal vitamin E supplementation significantly increases α-tocopherol concentrations in breast milk 3:

• Natural α-tocopherol supplementation increases colostrum levels by 57% 3
• Synthetic α-tocopherol supplementation increases levels by 39% 3
• The natural form (RRR-α-tocopherol) is more efficient at raising milk concentrations 3

However, inadequate dietary intake is common and directly impacts milk content 4:

• 100% of Brazilian lactating women studied had inadequate vitamin E intake 4
• Breast milk vitamin E content appears to be a more sensitive marker of maternal nutritional status than blood concentrations 4
• As lactation progresses, vitamin E status worsens when dietary intake is inadequate 4

Factors That Do NOT Significantly Affect Milk Vitamin E

The following maternal variables have not been shown to consistently influence α-tocopherol levels in milk 5:

• Parity 5
• Anthropometric nutritional status 5
• Socioeconomic status 5
• Habitual dietary intake (when not supplemented) 5, 2

There is no significant correlation between dietary vitamin E intake and breast milk concentration in women not taking supplements 2.

Conflicting Evidence

The literature shows inconsistent results regarding the influence of 5:

• Maternal age
• Gestational age
• Maternal biochemical nutritional status

Clinical Implications

The α-tocopherol isomer is the form with the highest concentration in human plasma, tissues, and breast milk 6. This is the biologically active form that provides antioxidant protection to the infant 6.

Comparison with Infant Formula

Infant formulas contain significantly lower concentrations of α-tocopherol compared to colostrum 2. This indicates the need for additional vitamin E supplementation in bottle-fed infants during the initial 2-3 days of life 2.

Prenatal Considerations

Appreciable prenatal vitamin E accretion occurs in the third trimester with increasing fetal lipid stores and maximum maternal-fetal vitamin exchange 6. Pre-eclampsia and gestational diabetes increase the risk of vitamin E deficiency in premature infants 6.

Key Clinical Pitfalls

• Do not rely solely on maternal serum vitamin E levels to assess adequacy of milk content—breast milk concentrations are more sensitive indicators 4
• Be aware that mature milk may not provide adequate vitamin E to meet the 4 mg/day requirement for term infants 1
• Consider maternal supplementation in early lactation when dietary assessment indicates inadequate intake, as this can prevent later deficiency risks 4
• Natural vitamin E supplements are more effective than synthetic forms at increasing milk concentrations 3