How long should breastfed infants be supplemented with vitamin D (Vitamin D)?

Vitamin D Supplementation Duration for Breastfed Infants

All breastfed infants should receive 400 IU of vitamin D daily starting at hospital discharge and continuing throughout the entire breastfeeding period, regardless of duration. 1

When to Start and Stop Supplementation

• Begin vitamin D supplementation at hospital discharge, not at the first outpatient visit—this is a critical timing issue that should not be delayed. 1, 2

• Continue supplementation throughout the entire breastfeeding period for any infant consuming less than 28 ounces (approximately 840 mL) of commercial infant formula per day. 1, 2

• Discontinue supplementation only when the infant consistently consumes at least 28 ounces of vitamin D-fortified formula daily, as formula provides adequate vitamin D at this volume. 1, 3

Rationale for Continuous Supplementation

• Breast milk contains insufficient vitamin D to meet infant requirements, placing exclusively and partially breastfed infants at risk for vitamin D deficiency and rickets. 1, 4

• Modern lifestyle changes with decreased sunlight exposure have increased the risk of vitamin D deficiency in all infants, making supplementation necessary rather than relying on sun exposure. 1, 4

• The 400 IU/day dose is based on preventing vitamin D deficiency and insufficiency, which are associated with increased risk of rickets and poor bone mineralization. 2, 5

Alternative Strategy: Maternal Supplementation

• Maternal supplementation with 6,000-6,400 IU of vitamin D daily can serve as an alternative to direct infant supplementation, providing adequate vitamin D through breast milk. 1, 2

• This approach may be preferred when:

  • Direct infant supplementation compliance is challenging 1
  • The mother prefers to be the sole source of infant vitamin D 1
  • Exclusive breastfeeding is planned for ≥6 months 1
  • Baseline maternal vitamin D deficiency exists 1

• However, maternal supplementation requires higher doses (≥4,000 IU/day) to achieve similar infant 25-OH vitamin D levels as direct infant supplementation of 400 IU/day. 6

Special Populations Requiring Extended Supplementation

• Preterm infants require 200-1,000 IU/day (or 80-400 IU/kg/day) and should continue supplementation along with multivitamin preparations until consuming a completely mixed diet with normalized growth and hematologic status. 7, 1, 3

• Infants on long-term parenteral nutrition should be monitored periodically for vitamin D deficiency, with additional supplementation provided if 25(OH) vitamin D concentrations fall below 50 nmol/L (20 ng/mL). 7, 3

Critical Pitfalls to Avoid

• Do not delay supplementation until the 2-month visit—it must begin at hospital discharge to prevent early deficiency. 1, 2

• Do not assume mixed-fed infants don't need supplementation—they require vitamin D until consistently consuming at least 28 ounces of formula daily. 1, 2

• Do not rely on sunlight exposure alone—modern recommendations prioritize supplementation over sun exposure due to skin cancer risk and difficulty determining adequate exposure. 1

• Do not stop supplementation arbitrarily at 6 or 12 months—continue as long as breastfeeding continues and formula intake remains below 28 ounces daily. 1, 3

Practical Implementation

• The American Academy of Pediatrics recommends 400 IU/day for all infants 0-12 months from all sources (diet plus supplements), regardless of feeding method. 3

• After 12 months of age, if the child continues breastfeeding without adequate dietary vitamin D sources, increase supplementation to 600 IU/day per AAP guidelines for children 1-18 years. 3

• Compliance with vitamin D supplementation remains low in practice (only 5-13% of exclusively breastfed infants meet recommendations), making clear communication about duration essential. 8