RT Journal Article SR Electronic T1 Measurement of vitamin D3 metabolites in smelter workers exposed to lead and cadmium. JF Occupational and Environmental Medicine JO Occup Environ Med FD BMJ Publishing Group Ltd SP 788 OP 788 DO 10.1136/oem.56.11.788a VO 56 IS 11 A1 H Mason A1 D Chettle YR 1999 UL http://oem.bmj.com/content/56/11/788.1.abstract AB