Associations between Plasma Folate and Vitamin B12, Blood Lead, and Bone Mineral Density among Adults and Elderly Who Received a Health Examination

This study hypothesized that plasma folate and vitamin B-12 levels modified the association between blood lead and cadmium and total urinary arsenic levels and bone loss. A total of 447 study subjects who received a physical examination at the Wanfang Hospital Medical Center were recruited. Bone loss was defined as a calcaneus bone mineral density T-score less than -1. Blood cadmium and lead concentrations were measured by ICP-MS. Urinary arsenic species were determined using HPLC-HG-AAS. A SimulTRAC-SNB radioassay was used to measure plasma folate, vitamin B-12, and homocysteine levels. Total urinary arsenic and blood lead concentration were positively correlated with the odds ratio (OR) for bone loss in a dose-response manner. The OR and 95% confidence interval (CI) for bone loss in participants with blood lead concentrations > 56.14 versus <= 33.82 mu g/dL were 1.82 and 1.10-3.01. No correlation between plasma folate and vitamin B-12 levels alone and bone loss was observed. However, this study is the first observational study to find that blood lead concentrations tend to increase the OR of bone loss in a low plasma folate and plasma vitamin B-12 group with multivariate ORs (95% CI) of 2.44 (0.85-6.96).

Automated summary

This study investigated the modifying effect of plasma folate and vitamin B-12 levels on the association between blood lead, cadmium, total urinary arsenic levels, and bone loss. The findings suggest that high blood lead and total urinary arsenic levels are positively correlated with bone loss, while plasma folate and vitamin B-12 levels alone do not show a direct correlation with bone loss. However, in individuals with low plasma folate and vitamin B-12 levels, high blood lead concentrations may increase the risk of bone loss.