Low Blood Zinc Levels Seen in 32% of Infants, Toddlers in Small Study

Teresa Carvalho, MS avatar

by Teresa Carvalho, MS |

Share this article:

Share article via email
azithromycin for infants | Cystic Fibrosis News Today | illustration of infant sleeping

Nearly one-third of infants and toddlers with cystic fibrosis (CF) evaluated in a small study had low blood levels of zinc — a mineral whose insufficiency is associated with poor growth in otherwise healthy children.

Still, the role of blood zinc levels “in growth and nutrition outcomes” for CF children up to age 3 remains unclear, its researchers wrote, and further investigation is necessary.

The study, “Zinc Status and Growth in Infants and Young Children with Cystic Fibrosis,” was led by scientists at Indiana University School of Medicine, and published in the journal Pediatric Pulmonology.

Zinc, an essential mineral, plays a crucial role in human metabolism, and is known to affect growth in the early years of life.

Recommended Reading
preterm births

CF Babies More Likely to be Born Preterm, Weigh Less, Study Finds

“Zinc deficiency is associated with poor growth in children without cystic fibrosis (CF), but its impact on growth in children with CF is unknown,” the researchers wrote.

Because babies with CF are less able to regulate zinc levels in the body, they are at an increased risk of zinc deficiency. As such, the growth of these children may be affected, which can have an impact on lung health over the long term.

However, few studies have looked a blood zinc concentrations and age-relevant growth in children with CF, and particularly in those 3 years old or younger. Growth and nutrition in the early years of life have a determining role on health over time.

The research team studied the prevalence of low blood levels of zinc, investigated factors that contributed to those levels, and evaluated the relationship between zinc levels in the blood and growth in children with CF up to age 3.

In total, data was collected from 53 children enrolled in an observational CF study called FIRST (Feeding Infants Right … from the Start). The FIRST study aimed to identify the best diet for young children with CF, and to raise awareness of malnutrition in the earliest years of life and how it can affect the lungs.

Zinc deficiency was established when blood concentrations were less than 70 micrograms per deciliter (µg/dL). Growth was measured according to the Anthropometry Procedures Manual used in the 2009-10 National Nutrition and Health Examination Survey in the U.S.

To identify possible contributors to low zinc levels, the team also assessed these children for pancreatic insufficiency, a common gastrointestinal complication of CF marked by malabsorption of certain nutrients in the intestines. One sign of this insufficiency is meconium ileus, a condition in which the contents of a baby’s bowel (the meconium) are abnormally thick and sticky, causing an obstructed or blocked bowel.

Children’s age, birth weight, body length, and CF-causing mutations were among data collected. Zinc deficiency was found in 17 of the 53 children (32%); blood levels of zinc in the remaining 36 (68%) were considered sufficient.Boys were much more likely to be zinc deficient than girls — “a significant gender difference was observed,” the researchers wrote — and blood levels of this mineral tended to drop with increasing age. Zinc deficiency was also more common in children with two copies of F508del, the most common CF-causing mutation.
Children in the zinc-deficient group were more likely to have meconium ileus (29% vs. 14% in those without zinc deficiency), and more likely to have had a shorter body length at birth. Overall, researchers did not observe a significant relationship between blood levels of zinc and growth parameters. However, a lower weight-for-height was seen at age 3 in children with zinc deficiency.

Factors other than blood zinc levels may have greater contribution to overall growth and nutrition during the first years of life in children with CF, the study noted.

“These results suggest that the association between Zn [zinc] and growth requires further investigation … and that factors other than Zn may play a greater role in growth in infant and young” CF patients, the researchers wrote.

More studies “are needed to further our understanding of the role of Zn in growth,” the team concluded.