Vitamin D - No weak bones for baby!
Vitamin D3 is important to the development of strong, healthy bones. Its deficiency can lead to osteomalacia, also known as rickets, which is the impaired calcification of bones leading to bone softening and distortion. Vitamin D deficiency or insufficiency has increased due to decreased sunlight exposure (being mostly inside), clothing coverage, and sunscreen usage. A mother who is vitamin D deficient will not be able to provide adequate vitamin D to her breast milk fed infant through her breast milk. Of note, it is Vitamin D3 that readily transfers through breast milk. For this reason, the American Academy of Pediatrics recommends all breastfed infants be supplemented with vitamin D3.
A 2015 randomized controlled trial compared the efficacy of maternal vitamin D3 intake to that of infant vitamin D3 supplementation. Infant serum calcium, creatinine, phosphorus, and urinary calcium/creatinine ratios were measured at baseline (4-6 weeks post-partum), 4 months, and 7 months.
Infants whose only source of vitamin D was maternal intake of 6400 IU did not differ from those infants who received 400 IU on any of the lab parameters measured. There were no differences in infant serum calcium, creatinine, phosphorus, or urinary calcium/creatinine ratios. This study suggested that with oral vitamin D3 supplement of 6400 IU daily, the lactating mother could transfer enough vitamin D to her breast milk fed baby to meet the infant’s needs.
A study published in the June 2022 issue of Breastfeeding Medicine compared the bone mineral content and bone mineral density of infants directly supplemented with vitamin D to those whose mothers were supplemented instead. This study showed a non-statistically significant difference in bone mineral content and bone mineral density in infants directly given 400 IU of vitamin D3 and infants whose mothers were given 6400 IU vitamin D3 at 1, 4, and 7 months of age. This study further supports that daily maternal vitamin D3 supplementation with 6400 IU/day is an appropriate alternative to direct infant supplementation.
It is hard to remember to take medication daily! As with anything, taking medication daily means incorporating it into your routine. A newborn cannot tell time. A newborn cannot read a clock. A newborn does not have a schedule or a routine. So, the question becomes— what is easier for a family to incorporate into their routine? Giving the baby vitamin D directly? Or having mom take it herself? These studies support that either is a reasonable option to choose for infant bone health.
