A recent case-control study published by the journal Science Direct found that low vitamin D levels were associated with jaundice among newborns.
Newborns develop jaundice when excessive bilirubin is present in the blood. Bilirubin is a yellow compound that is formed in the liver due to the destruction of aged red blood cells. Approximately 50% of full-term newborns and about 80% of preterm infants develop jaundice within the first 10 days of life.
When jaundice occurs, the infant’s skin and eyes develop a yellowish appearance. Infants may become lethargic, potentially interfering with feeding. Because bilirubin can penetrate the blood-brain barrier, severe cases may cause permanent brain damage.
Neonatal jaundice is typically treated by the use of a medication that increases liver metabolism, thus lowering bilirubin levels. Another effective treatment for jaundice is phototherapy. Researchers discovered that exposing infants to UV, green and blue light results in a conformational change of the bilirubin, enabling the compound to be excreted.
Although UV light has shown to improve jaundice in infants, the fear of skin cancer has resulted in the many physicians opting to use narrow band blue light therapy. However, blue light does not result in the production of vitamin D.
Vitamin D has been proven to play a crucial role in maternal and fetal development. Since liver tissue is responsible for the first step of vitamin D activation in the body and the creation and conversion of bilirubin, researchers have hypothesized that vitamin D status may be associated with the development of jaundice in newborns.
Only one study to date has evaluated the relationship between vitamin D status and jaundice among healthy full-term infants, suggesting a correlation exists between infantile vitamin D levels and jaundice.
In an effort to further validate these findings, researchers recently conducted a case-control study. Infants were excluded from the study if they developed jaundice as a result of pathological causes (such as infection), if they had a history of asphyxia or if they were born with congenital abnormalities. If the mothers presented a history of liver or kidney disorders, gestational diabetes or hypertension and used anticonvulsant medication, they were also excluded from the study.
A total of 30 newborns between 2 – 10 days old with jaundice and 30 healthy non jaundiced newborns and their mothers from a teaching children’s hospital in southwestern Iran were included in the study. The researchers obtained maternal and neonatal blood samples to measure serum bilirubin levels, liver and kidney function, parathyroid hormone levels and 25(OH)D status.
Here is what the researchers found:
- The average 25(OH)D levels of newborns and their mothers were not significantly associated with bilirubin status.
- The body mass index (BMI) of mothers of jaundiced infants was significantly higher than mothers of healthy neonates (p = 0.041).
- The average vitamin D status among jaundiced newborns was 10 ng/ml lower compared to controls (p < 0.05).
The researchers concluded,
“Newborn vitamin D levels were significantly lower in jaundiced cases compared with those in the nonjaundiced healthy groups, which may reveal an association between indirect hyperbilirubinemia and serum vitamin D levels.”
As always, it is important to state the study’s limitations. Due to the observational design of the study, researchers were unable to prove a causal relationship between vitamin D status and jaundice among newborns. Furthermore, the small sample size and short study duration decreased the strength of the findings.
The researchers stated,
“The findings of this study need to be confirmed by future research, including studies with larger sample size and repetition of vitamin D measurements with a follow-up until the age of 15 days, when jaundice is resolved, and before starting vitamin D supplementation.”
Sturges, M. & Cannell, JJ. Vitamin D status associated with jaundice in newborns. The Vitamin D Council Blog & Newsletter, 2017.