Nearly One in Six Children on Weight-Loss and Diabetes Drugs Developed a Nutritional Deficiency Within a Year

A new study published in Childhood Obesity has found that nearly one in six children and teenagers prescribed GLP-1 receptor agonists for weight loss, prediabetes or type 2 diabetes developed a diagnosed nutritional deficiency within their first year of treatment, most commonly a lack of vitamin D. ScienceDaily's summary of the paper and a report in The Pharmaceutical Journal both describe the analysis, which drew on medical records for 2,031 US patients aged 10 to 17 with no prior history of nutritional deficiency before starting the medication.

What the numbers show

Vitamin D deficiency was diagnosed in 12.4 per cent of the children within a year, making it by far the most common problem, followed by nutritional anaemia at 1.55 per cent and iron-deficiency anaemia specifically at 1.44 per cent. HealthDay's coverage notes that liraglutide was the most commonly prescribed GLP-1 drug in the sample, used by 78.6 per cent of the children, followed by dulaglutide at 10.4 per cent and semaglutide, the compound behind Ozempic and Wegovy, at 9.1 per cent. The average age of the patients studied was 15, and just under two-thirds were girls.

The gap the researchers are most concerned about

Only 23.3 per cent of the children in the study had a nutrition therapy or counselling visit within 180 days of starting their medication, and among those who did, the average time to that first visit was 149 days, nearly five months into treatment. GLP-1 drugs work partly by sharply reducing appetite and food intake, which is the intended mechanism for weight loss but which also reduces the volume of food, and therefore the range of vitamins and minerals, a growing child or teenager is consuming, a side effect that reduced calorie counts alone do not capture.

Why the researchers call this under-recognised

The study's authors describe nutritional deficiency in paediatric GLP-1 patients as a meaningful and under-recognised risk, language chosen deliberately given how routine these medications have become in adolescent obesity treatment over the past two years. Their recommendation is not to change how the drugs are prescribed but to build nutrition therapy and counselling into the standard treatment pathway from the start, rather than as an afterthought triggered only once a deficiency has already been picked up on a lab test months into treatment.

What parents are being told to watch for

Vitamin D deficiency in growing children can affect bone development over a longer timescale than a single year captures, which is part of why the researchers are flagging it now rather than waiting for longer-term outcome data. None of the coverage of the study suggests GLP-1 drugs should be avoided in adolescents who have a genuine clinical need for them; the consistent message across the reporting is that a nutrition check should happen at the same appointment where the prescription is written, not five months and one deficiency diagnosis later.