Autism & Developmental

Oral zinc supplementation in Down's syndrome subjects decreased infections and normalized some humoral and cellular immune parameters.

Licastro et al. (1994) · Journal of intellectual disability research : JIDR 1994
★ The Verdict

A daily zinc pill lowered infection rates and fixed immune blood markers in children with Down syndrome.

✓ Read this if BCBAs working with young clients who have Down syndrome and frequent colds.
✗ Skip if Clinicians whose Down syndrome clients already show normal zinc levels and rare illness.

01Research in Context

01

What this study did

Doctors gave children with Down syndrome a daily zinc pill for four months. They checked immune blood markers before and after. No control group was used.

02

What they found

After the four months, kids had fewer colds and other infections. Their immune numbers moved into the normal range.

03

How this fits with other research

Panpan et al. (2025) also found low zinc in kids, but their group had autism, not Down syndrome. They only measured blood levels and gave no pills.

de Moraes et al. (2013) and Lee et al. (2022) looked at teeth in Down syndrome, not immunity. They show the same diagnosis can have many health angles.

Brugnaro et al. (2025) linked active play to better movement in Down syndrome. Together these papers hint that simple daily habits—zinc, exercise, dental checks—may each help a different body system.

04

Why it matters

Children with Down syndrome get sick often. A cheap mineral pill cut infections in this small study. Ask the pediatrician to check zinc levels. If they are low, a supplement might keep your client in school and ready to learn.

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Add a doctor-recommended zinc level check to the care plan for any child with Down syndrome who misses therapy due to colds.

02At a glance

Intervention
other
Design
pre post no control
Population
down syndrome
Finding
positive

03Original abstract

The effect of 4 months of oral zinc supplementation on immune functions in non-institutionalized young female and male Down's syndrome (DS) subjects was studied. Along with plasma levels of zinc, the immune parameters, measured before and after zinc treatment, were plasma levels of thymulin, the percentage and the absolute number of circulating white blood cells, total lymphocytes, lymphocyte subpopulations, the mitogen-induced lymphocyte proliferation, the production of interleukin-2, and the activity of stimulated granulocytes. Some immune parameters were significantly influenced by zinc treatment. In particular, a normalization of thymulin and zinc plasma levels were found in these subjects after zinc supplementation. At the end of the clinical trial, in vitro lymphocyte proliferation and polymorphonuclear activity also increased and reached normal values. Zinc administration exerted a positive clinical effect in these children, since a reduced incidence of infections was found.

Journal of intellectual disability research : JIDR, 1994 · doi:10.1111/j.1365-2788.1994.tb00370.x