There are several circulating bone markers that are useful for physicians in determining the bone quality. The
markers are composed of N-terminal propeptide of type I collagen (P1NP) which determines the bone formation,
undercarboxylated osteocalcin (UcOC) and N-mid fragment of osteocalcin (N-MID) which determines the bone remodeling,
C-telopeptide of type I collagen (βCTx) or betacrosslap (βCTx), pyridinoline (PYD) and deoxypyridinoline (DPD) which
determines the bone resorption. The vitamin named vitamin D (Vit D) also affects the bone property. However, there is little
information about the relationship of these biomarkers. In this experiment, the researchers investigated the correlation of the
circulating biomarkers and found the correlations between UcOC and βCTx (r = 0.471, p = 0.011), between UcOC and Vit
D (r = 0.39, p = 0.04), between N-MID and P1NP (r = 0.833, p = 0.000), between N-MID and βCTx (r = 0.641, p = 0.000)
and lastly between P1NP and βCTx (r = 0.657, p = 0.000) in the male group whereas the correlations between UcOC and
PYD (r = 0.318, p = 0.043), between UcOC and DPD (r = 0.551, p = 0.008), between N-MID and P1NP (r = 0.721, p =
0.000), between N-MID and βCTx (r = 0.719, p = 0.000), between N-MID and PYD (r = 0.485, p = 0.001), between N-MID
and Vit D (r = 0.347, p = 0.026), between P1NP and βCTx (r = 0.632, p = 0.000), between P1NP and PYD (r = 0.312, p =
0.047), between bCTx and PYD (r = 0.365, p = 0.019), between PYD and DPD (r = 0.567, p = 0.006) and lastly between PYD
and Vit D (r = 0.409, p = 0.008) were found in the females. In addition, the new biomolecule named matrix Gla protein (MGP),
a small protein produced by bone tissues was also investigated. The authors found the correlation between MGP and PYD (r
= 0.468, p = 0.012) in the males and found the correlations between UcOC and MGP (r = 0.421, p = 0.006), between N-MID
and MGP (r = 0.333, p = 0.033), between MGP and PYD (r = 0.471, p = 0.002), between MGP and DPD (r = 0.472, p =
0.026) in the female group.

Keywords: Correlation of bone biomarkers, Vitamin D, Matrix Gla protein, Betacrosslap (βCTx)