One in Six Children on GLP-1 Drugs Develops Nutritional Deficiencies, Study Finds

What Happened

Children prescribed a GLP-1 receptor agonist developed a new nutritional deficiency within their first year of treatment in 16.8% of cases, according to a national claims analysis published in the journal Childhood Obesity.

The study, led by researchers at Ann & Robert H. Lurie Children's Hospital of Chicago and Northwestern University, drew on administrative claims data covering more than 100 million patients between 2017 and 2022. It identified 2,031 GLP-1 users aged 10 to 17 who had continuous insurance enrollment and no prior diagnosis of a nutritional deficiency.

Vitamin D deficiency was the most common finding, diagnosed in 12.4% of pediatric patients within a year of starting therapy. Iron and calcium — nutrients the authors single out as critical during adolescence — were also flagged as areas of concern.

Liraglutide was the most prescribed agent in the cohort at 78.6%, followed by dulaglutide (10.4%) and semaglutide (9.1%).

Who Is Affected

• Adolescents on GLP-1 therapy for obesity, prediabetes, or type 2 diabetes — a population still building bone mass and passing through puberty, when micronutrient reserves are already drawn on for growth
• Prescribers and pediatricians, who the study shows are rarely delivering nutritional support: only 5% of patients received nutritional counseling within 30 days of starting a GLP-1, and fewer than 25% received it within six months
• Clinical researchers, for whom the data adds a nutritional dimension to the known gastrointestinal side-effect profile of this drug class

Timeline

• 2017–2022 — Claims window analyzed in the study
• September 2026 — Study published in Childhood Obesity and announced by the research team
• Ongoing — Liraglutide and semaglutide are FDA-approved for adolescents 12 and older with obesity, with clinical trials now underway in children aged 6 to 12

What This Means for Researchers

The deficiency rate matters because of who these patients are. Weight loss on GLP-1 therapy tends to include both fat and lean mass, and during adolescence rapid loss can affect muscle strength or bone density if protein and micronutrient intake are not maintained. Vitamin D, iron, and calcium are of particular concern for skeletal health and overall development during pubertal years.

The senior author frames the goal as acting proactively with nutritional support, rather than waiting until a deficiency is already diagnosed.

The analysis carries honest limitations: it captures diagnosis codes rather than lab-confirmed deficiency in every case, covers only continuously insured patients, and cannot fully isolate how much risk stems from the medication itself versus the underlying obesity or diabetes. Whether deficiencies persist beyond the first year, and whether they affect growth outcomes, remains an open question.

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Sources

Peer-reviewed clinical research published in Childhood Obesity, September 2026; university research announcements.