What is the recommended dose of vitamin D3 (cholecalciferol) for a newborn?

Newborn Vitamin D3 Dosing

All newborns should receive 400 IU of oral vitamin D3 (cholecalciferol) daily starting at hospital discharge, regardless of feeding method. 1

Standard Dosing by Feeding Method

Breastfed Infants

• Begin 400 IU/day at hospital discharge and continue throughout the entire breastfeeding period 1, 2
• There is no upper age limit for discontinuation—the key determinant is continuation of breastfeeding, not the infant's age 2
• Breast milk contains insufficient vitamin D to meet infant requirements, making supplementation essential 2

Formula-Fed Infants

• Provide 400 IU/day until the infant consistently consumes at least 28 ounces (approximately 840 mL) of vitamin D-fortified formula daily 1, 2
• Most infants reach approximately 400 IU daily from formula within the first 2 months if consuming routine cow milk-based formula 3
• Once the 28-ounce threshold is reliably met, supplementation can be discontinued 2

Mixed-Fed Infants

• Continue 400 IU/day supplementation until the infant reliably consumes at least 28 ounces of formula daily 1

Special Populations

Preterm Infants

• Initially require 200-400 IU/day, with some guidelines suggesting up to 800-1,000 IU/day for extremely preterm infants 1
• For preterm infants on parenteral nutrition, provide 200-1,000 IU/day (or 80-400 IU/kg/day) 1, 2
• Continue supplementation until consuming a completely mixed diet with normalized growth 2

Alternative Supplementation Strategy

Maternal supplementation: Lactating mothers can take 6,400 IU/day of vitamin D, which provides adequate vitamin D to the breastfed infant through breast milk 1, 2

Formulation and Safety

Preferred Formulation

• Cholecalciferol (vitamin D3) is preferred over ergocalciferol (vitamin D2) due to higher bioavailability and efficacy 1

Safety Thresholds

• Maximum safe daily dose is 1,000 IU/day for infants 0-6 months 1
• Maximum safe daily dose is 1,500 IU/day for infants 7-12 months 1
• Vitamin D toxicity is very uncommon, but caution should be used to avoid extremely concentrated high doses found in some commercially available drops 3

Monitoring

Target Levels

• Target serum 25-OH vitamin D level is >20 ng/mL (50 nmol/L) for bone health 1

When to Monitor

• Routine testing of serum 25-OH vitamin D levels is not recommended for healthy term or preterm infants receiving standard supplementation 1
• Reserve testing for infants with malabsorption conditions, chronic kidney disease, or those on long-term parenteral nutrition 1

Critical Pitfalls to Avoid

• 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 1
• Do not discontinue at an arbitrary age—base discontinuation on feeding method and volume, not age alone 2

Evidence Considerations

While research from low-middle-income countries suggests 800 IU/day may be more effective than 400 IU/day in preventing vitamin D insufficiency 4, and some studies show 21.3% of infants on 200 IU/day had levels below 30 mcg/L at 4 months 5, the American Academy of Pediatrics maintains 400 IU/day as the standard recommendation for healthy term infants 1. Higher doses have not been consistently shown to have specific clinical benefits for healthy infants in most populations 3.