A systematic review finds supplements can correct vitamin D deficiency in children and teenagers with excess weight, but offer no consistent improvement in insulin sensitivity, cholesterol or blood pressure.
Vitamin D supplements can raise blood levels in children and teenagers with obesity or overweight, but they do not appear to fix the metabolic problems that often travel with excess weight, according to a new systematic review and meta-analysis published in the International Journal of Obesity. The review, led by Alia Iftikhar of King Edward Medical University in Lahore, pulled together randomised trial evidence on cholecalciferol, the form of vitamin D commonly used in supplements, and found that correcting low vitamin D status was achievable, while broader gains in cardiometabolic health were not.
The analysis looked at 24 studies in total, with 11 trials providing data robust enough for pooled statistical analysis. Follow-up periods ranged from eight weeks to 12 months, and the researchers assessed the quality of the evidence using the Cochrane Risk of Bias tool. Earlier reviews have reached similar conclusions: a 2022 meta-analysis indexed by PubMed found that vitamin D supplementation reliably increased blood vitamin D levels in children and adolescents with excess weight, but did not significantly change body mass index, fat mass or lean body mass, while another review in 2023 reported only a modest rise in 25-hydroxyvitamin D levels and described the effects on metabolic and cardiovascular outcomes as uncertain.
The new review’s clearest result was biochemical rather than clinical. Children given vitamin D had higher 25-hydroxyvitamin D concentrations than those on placebo, confirming that supplementation can overcome the lower circulating levels often seen in obesity. That pattern is biologically plausible, because vitamin D is fat-soluble and can be distributed differently in people with larger fat stores. The authors also reported no adverse events in the trials they reviewed, which is reassuring given that some studies used relatively high doses. Still, safety in these trials should not be confused with proof that vitamin D changes the course of obesity-related illness.
Where parents and clinicians may have hoped for more dramatic results, the evidence was less encouraging. The review found some positive signals, including possible reductions in body mass index, triglycerides and inflammatory markers, but these were not strong enough to translate into a consistent improvement in overall metabolic health. In line with earlier pooled analyses, the new findings did not show convincing benefits for insulin sensitivity, lipid profiles or blood pressure. A separate meta-analysis of nine studies with 440 participants, published this year and indexed by PubMed, likewise found no meaningful improvement in BMI, insulin sensitivity or most lipid measures, though it did note a fall in HDL cholesterol.
Taken together, the research suggests a narrow but important role for vitamin D in this group. Children and adolescents with obesity are at higher risk of deficiency, and supplementation remains a sensible way to restore adequate blood levels, particularly because low vitamin D can affect bone mineralisation during growth. But the evidence does not support vitamin D as a stand-alone treatment for the metabolic consequences of excess weight. The deeper drivers of cardiometabolic risk in childhood obesity, including diet, activity and sustained weight management, still appear to require interventions far beyond a daily supplement.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
