Does vitamin D have a potential role in precocious puberty? A meta-analysis

Background: Precocious puberty, one of the common pediatric endocrine system diseases, has been related to reduced adult height, adverse psychological outcomes and long-term health consequences. Previous findings have found that low levels of vitamin D appear to be associated with the characteristics of precocious puberty such as early menarche. However, the effect of vitamin D on precocious puberty remains controversial. Methods: The published literature was searched from PubMed, Web of Science, Cochrane Library, MEDLINE, EMBASE, CNKI, Wan Fang and VIP databases up to October 2022. A randomized effect model was used to perform a meta-analysis to evaluate differences in vitamin D concentration between precocious puberty subjects and normal subjects, the risk of precocious puberty in subjects with low vitamin D levels, and the effect of supplementation of vitamin D on subjects with precocious puberty on medication. Results: Our study found that precocious puberty subjects had lower serum vitamin D levels than the normal population (standardized mean difference (SMD) = -1.16 ng ml^-1 and 95% confidence interval (CI) = -1.41 and -0.91 ng ml^-1). Meanwhile, the lower level of vitamin D was associated with the risk of precocious puberty (odd ratio (OR) = 2.25 and 95% CI = 1.66 and 3.04). Moreover, compared with gonadotropin-releasing hormone analogue (GnRHa) intervention alone, subjects receiving GnRHa + vitamin D intervention had significantly lower luteinizing hormone (LH), follicle-stimulating hormone (FSH), and estradiol levels and bone age, and higher predicted adult height (PAH). Conclusions: Vitamin D may have a potential role in precocious puberty and more data from large clinical trials are needed to confirm the findings.