Vitamin D Supplementation for Bone Mass gains in Infants with lower Vitamin D levels

The dose of supplemental vitamin D needed in infants born with 25-hydroxyvitamin D (25[OH]D) serum concentrations less than 50 nmol/L (i.e., 20 ng/mL) remains unclear. The present study determined if a higher dose (1000 IU vs. 400 IU/day) is needed in infants born with 25(OH)D concentrations <50 nmol/L for bone mineral accumulation across infancy.

The study enrolled 139 healthy term singletons from 866 infants evaluated for vitamin D status at birth. It collected capillary Blood 24 to 36 hours after birth to assess serum total 25(OH)D concentrations and randomized infants with 25(OH)D concentrations <50 nmol/L to receive oral vitamin D3 supplementation, either 1000 IU or 400 IU/day, from age 1 to 12 months. It considered infants with 25(OH)D concentrations of 50 nmol/L or greater as a reference group.

The study undertook measurements at ages 1, 3, 6, and 12 months including whole-body bone mineral content, lumbar spine bone mineral content, bone mineral density, and serum 25(OH)D3.

The study observed-

• Inclusion of 139 infants, 58.3% of which were male, with the median (IQR) gestational age at birth of 39.6 (38.9-40.6) weeks. 
• Inclusion of 49 infants in the 1000 IU/day group, 49 in the 400 IU/day group, and 41 in the reference group. 
• Similar mean (SD) whole-body bone mineral content between trial groups over time. 
• Similar lumbar spine bone mineral content or density. 
• Significantly higher mean (SD) serum 25(OH)D3 concentrations in the 1000 IU/day group from age 3 to 12 months compared with the 400 IU per day trial group.

This study shows an increased dose of vitamin D supplementation in infants born with 25(OH)D concentrations <50 nmol/L does not render advantages to bone mass in infancy. It also supports a standard dose of 400 IU/day of vitamin D supplementation for breastfed infants.

Gharibeh N, Razaghi M, Vanstone CA, et al. Effect of Vitamin D Supplementation on Bone Mass in Infants With 25-Hydroxyvitamin D Concentrations Less Than 50 nmol/L: A Prespecified Secondary Analysis of a Randomized Clinical Trial. JAMA Pediatr. 2023. doi:10.1001/jamapediatrics.2022.5837