The relationship between vitamin K levels and short stature in children with idiopathic short stature

Aim: Short stature is an important issue both socially and medically. Vitamin K serves as a coenzyme for the enzyme gamma-glutamyl carboxylase and plays a role in adding a carboxyl group to the gamma-carbon of glutamic acid residues in 17 vitamin K-dependent proteins. Some of these vitamin K-dependent proteins also affect bone metabolism. This project aims to investigate the role of vitamin K deficiency during childhood in the development of idiopathic short stature (ISS) and to explore the potential mechanisms mediating this effect, based on the relationship between vitamin K and bone tissue growth/development. Materials and Methods: Our study included 44 children diagnosed with ISS (22 girls and 22 boys, age: 10,70±3,40) and 44 age- and sex-matched children of normal height (22 girls and 22 boys, age: 10,60±3,50). In both the ISS and control groups, tests were performed to measure levels of IGF-I, IGF-BP3, total alkaline phosphatase, intact PTH, total 25-hydroxy vitamin D, vitamin K (in the forms of phylloquinone, menaquinone-4, and menaquinone-7), N-mid osteocalcin, matrix gla protein, and uncarboxylated osteocalcin. Results: In the ISS group, levels of phylloquinone, MK-4, MK-7, IGF-I, IGF-BP3, and total 25(OH)D3 were significantly lower compared to the control group. Additionally, significant positive correlations were found between phylloquinone, MK-4, MK-7, and height, body weight, and height SDS. The strongest correlation was observed between MK-7 and height SDS (p<0.0001, r=0.665). Discussion: This project identified reduced vitamin K levels in children with ISS. Moreover, forms of vitamin K were found to show a positive correlation, particularly with height SDS and height. These findings support the significant role of vitamin K in bone growth and development and suggest that vitamin K may provide a novel therapeutic approach for the prevention and/or treatment of ISS. Keywords: Idiopathic short stature, vitamin K, osteocalcin, MGP