Nearly one in six children prescribed GLP-1 weight-loss drugs was diagnosed with a nutritional deficiency within a year, a new US study has found. The study of 2,031 children aged 10 to 17 found that 16.8 per cent developed a deficiency or related complication within 365 days.

Vitamin D deficiency was the most common, affecting 12.4 per cent within a year, while nutritional anaemia was found in 1.55 per cent and iron-deficiency anaemia in 1.44 per cent. About 10.2 per cent were diagnosed within 180 days. The children had a mean age of 15, and most had obesity or type 2 diabetes.

Liraglutide was the most prescribed GLP-1 at 78.6 per cent, followed by dulaglutide and semaglutide. Only 5 per cent of patients received nutritional counselling within 30 days of starting a GLP-1, and fewer than 25 per cent received it within six months.

The researchers stress the analysis was descriptive and does not establish that the drugs directly caused the deficiencies. Senior author Justin Ryder said the findings should bring recognition to proactive nutritional management when GLP-1s are prescribed to children. The study was published in Childhood Obesity on September 17, 2026.