Vitamin D Supplementation in Infants

Standard Dosing

The American Academy of Pediatrics recommends that all infants receive 400 IU of oral vitamin D daily starting at hospital discharge, regardless of whether they are breastfed or formula-fed, to prevent vitamin D deficiency and rickets 1, 2
Breastfed infants should begin 400 IU/day at hospital discharge and continue throughout the breastfeeding period 1, 2
Formula-fed infants should receive 400 IU/day until the infant consistently consumes at least 28 ounces (approximately 840 mL) of vitamin D-fortified formula daily 1
Mixed-fed infants should continue 400 IU/day supplementation until the infant reliably consumes at least 28 ounces of formula daily 1

Preterm infants require 200-400 IU/day initially, with some guidelines suggesting up to 800-1,000 IU/day for extremely preterm infants 1, 2
For preterm infants on parenteral nutrition, provide 200-1,000 IU/day (or 80-400 IU/kg/day) 3, 2

Lactating mothers can take 6,400 IU/day of vitamin D, which provides adequate vitamin D to the breastfed infant through breast milk 1

The maximum safe daily dose is 1,000 IU/day for infants 0-6 months and 1,500 IU/day for infants 7-12 months 4, 2

Cholecalciferol (vitamin D3) is preferred over ergocalciferol (vitamin D2) due to higher bioavailability and efficacy 4, 2

The target serum 25-OH vitamin D level is >20 ng/mL (50 nmol/L) for bone health 4, 2
Routine testing of serum 25-OH vitamin D levels is not recommended for healthy term or preterm infants receiving standard supplementation, but should be reserved for infants with malabsorption conditions, chronic kidney disease, or those on long-term parenteral nutrition 4, 2

Do not delay supplementation until the first outpatient visit—begin at hospital discharge 1
Do not assume formula-fed infants receive adequate vitamin D until they consistently consume ≥28 ounces daily 1
Ensure adherence to the supplementation regimen, as inconsistent supplementation is a common cause of treatment failure 4