New research published in Annals of Pediatric Endocrinology & Metabolism has found that girls with early onset of puberty have lower vitamin D levels compared to girls with normal development.
The early onset of puberty is referred to as precocious puberty. The condition is about 10-20 fold higher in girls than boys. Girls normally begin puberty between the ages of 9 and 14 years. Precocious puberty in girls is defined as puberty that begins at age eight or younger.
Children who start puberty at an early age are likely to stop growing early, resulting in them having a shorter stature. It can also cause children to be self-conscious, which can result in emotional and psychological damage.
Studies have suggested a relationship between vitamin D levels and precocious puberty. A study from 2013 found that girls with precocious puberty were significantly more likely to have low vitamin D levels. However, beyond studies looking at the prevalence of vitamin D deficiency there hasn’t been much additional research.
Researchers from Korea recently enrolled 60 girls with precocious puberty and 30 girls with normal development into a study to further investigate the association between vitamin D status and precocious puberty.
The researchers measured the vitamin D levels of girls with precocious puberty to girls with normal maturation and obtained the following results:
- Girls with precocious puberty had about three times the odds of having vitamin D deficiency.
- Vitamin D deficiency was present in 70% of girls with precocious puberty, with deficiency defined as levels lower than 20 ng/ml.
- Vitamin D deficiency was present in 43.3% of girls with regular development.
- Only two girls with normal maturation were considered vitamin D sufficient, whereas none of the 60 girls with precocious puberty had sufficient vitamin D levels.
The researchers summarized their findings,
“In conclusion, our study indicated that vitamin D deficiency was more common in girls with precocious puberty than girls with normal patterns of sexual maturation.”
The researchers acknowledged that the small sample size and the inclusion of mostly vitamin D deficient and insufficient girls limits the study’s ability to generalize the findings.
The role of vitamin D in puberty remains somewhat unclear. The researchers proposed explanations for the high prevalence of vitamin D deficiency in girls with precocious puberty. First, vitamin D is inversely associated with obesity. In this study, they found that girls with precocious puberty weighed more than those with normal development. Although the BMI did not significantly differ between the two groups.
Another proposed mechanism for vitamin D’s role in precocious puberty is its inverse relationship with insulin-like growth factor 1 (IGF-1). IGF-1 has been shown to modulate the onset of puberty.
Future research is needed to determine how vitamin D deficiency affects the development of precocious puberty and whether correcting for deficiency reduces the risk or helps manage aspects of precocious puberty.