Children who start GLP-1 medications for weight loss, prediabetes or type 2 diabetes may face a real risk of nutritional shortfalls in the first year.
That is the finding from a large new analysis of US pediatric prescribing data.
Researchers at Ann & Robert H. Lurie Children's Hospital of Chicago followed 2,031 children aged 10 to 17 who had been prescribed a GLP-1 drug.
Within twelve months, 16.8 percent were diagnosed with at least one nutritional deficiency.
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Vitamin D deficiency was by far the most common, showing up in 12.4 percent of the young patients. The findings were published September 17, 2026, in the journal Childhood Obesity.
What the study looked at
The team drew on national claims data covering more than 100 million patients between 2017 and 2022.
None of the 2,031 children had a nutritional deficiency diagnosis before starting a GLP-1. That baseline is what makes the 16.8 percent figure so striking.
Liraglutide (sold as Saxenda by Novo Nordisk) was by far the most prescribed drug at 78.6 percent. Dulaglutide (Trulicity, from Eli Lilly) accounted for 10.4 percent, and semaglutide (the active ingredient in Novo Nordisk's Ozempic and Wegovy) 9.1 percent.
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GLP-1 drugs mimic a gut hormone that slows stomach emptying and blunts appetite. That is also why they can quietly reduce the intake of key nutrients over time.
The counseling gap
The other headline finding is what did not happen. Only 5 percent of these children received nutritional counseling within the first 30 days of starting a GLP-1. Fewer than 25 percent got any counseling within six months.
Senior author Justin Ryder, vice chair of research in the Department of Surgery at Lurie Children's, said in a statement that "nutritional support needs to play a critical role once treatment with a GLP-1 medication is initiated."
He added that the team hopes the findings "bring much needed recognition to the importance of proactive nutritional management when GLP-1s are prescribed to children."
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Why kids are more vulnerable
Adolescence is a period of rapid growth and skeletal development. Vitamin D, iron and calcium are particularly critical during these years, when a shortfall can leave lasting marks on bone strength.
Vitamin D helps the body absorb calcium and build bone. Low vitamin D has also been linked in other research to weaker muscles even before bones show damage. That is one reason the 12.4 percent figure sits at the top of the concern list.
What parents can do now
The study does not tell parents to stop treatment. GLP-1 medications remain FDA approved for adolescents aged 12 and older with obesity, and pediatric guidelines now include them as part of a broader obesity plan.
What the data do suggest is that a conversation with the prescribing clinician about diet, blood tests and a referral to a dietitian should happen at the start of treatment, not months in.
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Parents whose child is starting or is already on a GLP-1 can ask the pediatrician about baseline vitamin D, iron and calcium checks, and about follow-up testing during the first year.
If symptoms such as unusual fatigue, muscle weakness or bone pain appear, they should be flagged to the doctor without delay.
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This article is made and published by Mie Hermansen, who may have used AI in the preparation.