Calcium Intake, Vitamin D and Bone Health Status of Post-menopausal Chinese Women in Kuala Lumpur

ABSTRACT

Bone health status was investigated in 178 free-living Chinese post-menopausal women in Kuala Lumpur. Body mass index (BMI), body composition (using whole body DXA), calcium intake and serum 25-OH vitamin D status were measured along with biochemical markers of bone turnover, that is, pro-collagen Type 1 N-terminal peptide (P1NP), osteocalcin (OC) and C-telopeptide ß cross link of Type 1 collagen (CTX- β). Bone mineral density (BMD) was measured using DXA (Hologic, USA) at the lumbar spine, femoral neck and total hip. Results showed that osteopenia was present in 50% of the subjects at the spine and 57.9% at the femoral neck. Osteoporosis was diagnosed in 10% of the subjects at both the femoral neck and spine. A total of 29.3% of the subjects had high levels of CTX- ß. Mean serum level of 25-OH vitamin D was 60.4+15.6 nmol/L and 50.6% of the subjects had hypovitaminosis D (defined as <50 nmol/l). Mean total calcium intake of the subjects was 497 + 233 mg, of which only 14% met the RNI for calcium with the additional intake of calcium supplements. Body fat was also significantly correlated (r=0.181, p<0.05) with BMD at the spine but not BMD at the femoral neck. Lean body mass was positively correlated with BMD at the spine (r=0.289, p<0.001) and femoral neck (r=0.295, p<0.001). CTX-β was negatively correlated with BMD at the spine (r= -0.235, p<0.001), whereas P1NP (r=-0.215, p<0.001) and osteocalcin (r=-0.265, p<0.001) were both negatively correlated with BMD at the femoral neck. Generally, the study found that women with osteopenia had higher levels of bone turnover markers, less lean body mass and lower calcium intake than women with normal BMD. In conclusion, this study demonstrated that the majority of free living Chinese post-menopausal women in Kuala Lumpur have low calcium intake, low 25-OH vitamin D status and low bone mass and elevated biochemical markers of bone turnover.