Vitamin D and its relationship with markers of bone metabolism in healthy Asian women.
BACKGROUND
In this study, we aimed to determine the normal ranges of 25-hydroxy-vitamin D(3) (25-OHD(3)), parathyroid hormone (PTH), and the markers of bone turnover, procollagen type 1 N propeptide (P1NP) and C-terminal cross-linked telopeptide of type 1 collagen (CTX), in normal healthy women in Singapore, and to explore the relationship between vitamin D, PTH, and these markers of bone turnover in the women.


METHODS
One hundred and ninety-seven healthy women, aged 25 to 60, were selected from a hospital staff health screening program; 68% were Chinese, 18% Malay, and 14% Indian. P1NP, CTX, and 25-OHD(3) were measured using the Roche Cobas® electrochemiluminescence immunoassay. Serum PTH was measured using the Siemens ADVIA Centaur® immunoassay.


RESULTS
Sixty-five percent had 25-OHD(3) concentrations <50 nmol/l. Vitamin D insufficiency (25-OHD(3) < 50 nmol/l) was more prevalent in Malays (89%) and Indians (82%) compared to Chinese (56%). There was no correlation between vitamin D and age. PTH positively correlated with age, and Malays and Indians had higher PTH concentrations than Chinese. There was an inverse correlation between PTH and 25-OHD(3), but no threshold of 25-OHD(3) concentrations at which PTH plateaued. The bone turnover markers P1NP and CTX inversely correlated with age but were not different between ethnic groups. CTX and P1NP exhibited good correlation, however, there was no significant correlation between 25-OHD(3) or PTH concentrations and the bone turnover markers P1NP and CTX.


CONCLUSIONS
Healthy women in Singapore have a high prevalence of vitamin D insufficiency. Vitamin D insufficiency was more prevalent in Malays and Indians compared to Chinese.
['Tan|Karen M L|KM|', 'Saw|Sharon|S|', 'Sethi|Sunil K|SK|']
D000328:Adult D044466:Asians D015415:Biomarkers D001842:Bone and Bones D002112:Calcifediol D002681:China D024042:Collagen Type I D005260:Female D006801:Humans D007194:India D008296:Malaysia D008875:Middle Aged D010281:Parathyroid Hormone D010446:Peptide Fragments D010455:Peptides D011347:Procollagen D012016:Reference Values D012846:Singapore D014808:Vitamin D Deficiency D044465:Whites
healthy Asian women PTH P1NP CTX 25-OHD3 association