Puberty normally begins at the age of 10 years to 14 years in girls while a little later in boys, usually at the age of 12 years to 16 years. In girls, early onset of puberty is diagnosed when sexual growth and development occurs before the age of 8 years whereas in boys it is diagnosed when puberty changes appear before the age of 9 years.
The researchers have established links between deficiencies of vitamin D to a variety of diseases such as, obesity, cancer and autoimmune diseases.
Precocious puberty in girls has been attributed to insufficient levels of vitamin D. The scientists said that the exact association between vitamin D and early onset of puberty is yet unclear.
In order to assess the mechanism, the experts compared the blood levels of vitamin D in girls with normal and early development.
The scientists noted girls with early onset of puberty had severe vitamin D deficiency as compared to girls having age-appropriate development.
About 44 percent of girls with precocious development had severe deficiency of vitamin D and 21 percent of girls with normal development reported of vitamin D deficiency.
The scientist also analyzed the role of neurons in stimulating the release of hormones responsible for the ovulation process.
The experts used the neuron-stimulating compound called N-methyl-D-aspartate, or NMDA for triggering the neurons that is responsible for liberating gonadotropin-releasing hormone or GnRH.
It was found that vitamin D was related with the inhibition of the NMDA-mediated neuron activities on GnRH neurons.
The lead author Min Sun Kim, MD, PhD, assistant professor at Chonbuk National University Medical School in Jeonju, South Korea mentioned, "If we understand more about the action mechanism of vitamin D on GnRH neuronal activities, we can find a clue to control of precocious puberty using vitamin D or related molecules."
Prof. Min Sun Kim further added, "Our results suggest that vitamin D may inhibit early pubertal onset and/or the rapid progression of puberty, at least in part, through the suppression of NMDA-mediated GnRH neuronal excitation in humans."
Around 110 girls in the age group of 7 to 10 years were enrolled for the study.
Normal age-appropriate development was noted in about seventy five girls while precocious puberty was seen in thirty five girls.
Tanner scale was used for assessing physical development to differentiate precocious development versus normal growth and development.
Kim said that further research was required to find out the actual relationship between vitamin D deficiency and early puberty in girls.
Source-Medindia
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