What are the selenium intake recommendations for breastfeeding mothers?

Selenium Recommendations for Breastfeeding Mothers

Based on the European Food Safety Authority (EFSA) guidelines, breastfeeding women should consume 85 μg/day of selenium to support optimal maternal and infant health. 1

Selenium Requirements During Lactation

Recommended Intake

• The adequate intake for selenium in lactating women is 85 μg/day 1
• This recommendation is based on:
  • Base requirement for adult women: 70 μg/day
  • Additional 15 μg/day to compensate for selenium secreted in breast milk (approximately 12 μg/day) 1
  • Accounts for an absorption efficiency of 70% from typical diets

Selenium Transfer to Breast Milk

• Selenium appears in breast milk primarily as:
  • Glutathione peroxidase (4-32% of total selenium)
  • Selenocystamine
  • Selenocystine
  • Selenomethionine 2
• Breast milk selenium concentrations naturally decrease throughout lactation:
  • Colostrum (0-5 days): median 26 μg/L
  • Transitional milk (6-21 days): median 18 μg/L
  • Mature milk (1-3 months): median 15 μg/L
  • Late lactation (>5 months): median 17 μg/L 2

Clinical Significance and Outcomes

Maternal Health Considerations

• Selenium plays crucial roles in:
  • Antioxidant defense through selenoproteins
  • Thyroid hormone formation
  • Immune function (stimulates antibody formation and activity of helper T cells, cytotoxic T cells, and Natural Killer cells) 3
• Inadequate selenium intake during lactation may be common:
  • Studies show 56% of breastfeeding mothers may have intakes below the Estimated Average Requirement of 65 μg/day 4
  • Maternal plasma selenium levels are typically lower in lactating compared to non-lactating women 5
• Potential link between selenium status and postnatal depression, though evidence remains inconclusive 4

Infant Health Considerations

• Breast-fed infants generally maintain better selenium status than formula-fed infants, despite variations in breast milk selenium content 2
• Estimated infant selenium intakes from breast milk may often fall below recommended levels:
  • Studies show 85-93% of exclusively breastfed infants may have intakes below the Adequate Intake of 12 μg/day 4
• Selenium deficiency in infants can potentially impact:
  • Antioxidant defense systems
  • Thyroid function
  • Immune development

Practical Recommendations

Dietary Sources of Selenium

• Selenium content in foods varies widely based on soil selenium content where foods are grown
• Good dietary sources include:
  • Brazil nuts
  • Seafood
  • Organ meats
  • Whole grains
  • Eggs

Supplementation Considerations

• Organic selenium (yeast-Se) appears more effective than inorganic forms (selenite) in increasing:
  • Maternal serum selenium
  • Breast milk selenium
  • Infant serum selenium 6
• A daily intake of 100 μg of yeast-selenium has been shown to be safe and effective in improving selenium status during lactation 6

Monitoring and Assessment

• Selenium status can be assessed through:
  • Maternal plasma/serum selenium levels
  • Urinary selenium excretion
  • Breast milk selenium concentration

Special Considerations

• Selenium requirements may be higher in regions with low soil selenium content
• Women following restrictive diets (vegan, vegetarian) may need particular attention to selenium intake
• Excessive selenium intake should be avoided as toxicity can occur at high levels