Introduction: Scarcity of data found in regard to association of vitamin D level with bone mineral density (BMD). Our study aimed to determine the correlation of vitamin D with BMD and intact parathyroid hormone (iPTH) among healthy Malay adult. Methods: This cross-sectional study recruited 126 healthy Malay volunteers (aged 21–45 years old) from Kota Bharu, Malaysia. Serum total calcium, albumin, phosphorus, 25-hydroxyvitamin D (25(OH)D), and iPTH were measured. BMD was assessed with dual energy X-ray absorptiometry (DXA) scan over left hip (right hip in case of problem with left hip) and lumbar spine (L1 – L4 vertebrae). Results: The mean serum 25(OH)D was 38.91 ± 14.07 nmol/L. Out of 126 study subjects, 104 subjects (82.5%) had insufficient level of vitamin D (< 50 nmol/L). Mean hip and lumbar BMD were 0.952 ± 0.145 g/cm2 and 1.006 ± 0.133 g/cm2 respectively. According to T-score, 93 subjects (73.8%) had normal T-score of ≥ -1, 33 subjects (26.2%) had osteopenia (T-score -2.5 to -1) and none had osteoporosis (T-score ≤ -2.5). Significant positive correlation between serum 25(OH)D and hip BMD (r = 0.234, p = 0.009) was observed, but no correlation was found between serum 25(OH)D and lumbar BMD. Meanwhile, significant inverse correlation between serum 25(OH)D and iPTH was observed (r = -0.324, p < 0.001). Conclusion: High prevalence of vitamin D insufficiency was observed among healthy Malay population, but majority had normal bone density. Nonetheless, serum 25(OH)D was positively correlated with BMD and inversely correlated with iPTH. Our findings support the role of vitamin D for maintaining bone health.

Blood collection tubes containing separator gel are widely used in many clinical laboratories because of easy to use, convenience and several other advantages. However, they are not void of limitation. We describe an unusual case with a floating separator gel in the primary blood collection tube. The blood sample was collected into a BD Vacutainer SST II Advance tube, from a 51 years old man admitted for community acquired pneumonia and had history of hyperproteinaemia. Inappropriate positioning of the separator gel was observed after centrifugation, whereby the separator gel floated above the serum. Detection of abnormal separator gel floatation pattern in this patient’s sample before analysis had prevented potential technical problem and production of erroneous result caused by aspiration of separator gel. The limitation of blood collection tube with separator gel especially in patients with hyperproteinaemia should be made aware among laboratory personnel and physicians.