Associations of Dietary Calcium Intake and Serum Calcium Level with Blood Lead Levels in Korean Male Lead Workers

A cross-sectional study was performed to estimate the nutritional status of Korean male lead workers and to assess the relationship between calcium nutritional status and blood lead levels. A flood consumption survey was conducted by the 24-hr recall method with 118 lead workers and 63 non-lead exposed controls. Blood lead levels were analyzed from whole blood and serum calcium concentrations were also assessed. Results of dietary analysis showed Korean lead workers consumed relatively sufficient nutrients (more than 75% of RDA) except, calcium. Mean dietary calcium intake of lead workers was 502.2mg(72% of RDA) while that of the non-lead workers was estimated as 600.8mg(86% of RDA). Intakes of protein, iron, niacin and vitamin C of lead workers were significantly lower than those of non-lead workers. There was a wide range of blood lead levels(5.5 to 73.5$\mu\textrm{g}$/㎗) observed while mean blood lead level of lead workers was 30.9$\mu\textrm{g}$/㎗. However, 98% of lead workers showed normal serum ca1cium concentrations (range ; 8.9 to 10.7mg/㎗, mean ; 9.77mg/㎗) while 66% of lead workers were estimated to intake a dietary calcium lower than 75% of RDA. Mean blood lead levels of non-1ead workers were significantly lower(mean ; 5.1$\mu\textrm{g}$/㎗, p ＜ 0.001) and the serum calcium concentration was significantly higher(mean ; 10.20mg/㎗, p ＜ 0.001) than lead workers. Results of unadjusted correlation showed that serum calcium level and dietary calcium intake were negatively correlated with blood lead concentration. In a multiple regression of blood lead levels with variables known as affecting blood lead 1eve1 such as age, body mass index and occupational lead exposure, serum calcium was insignificant while dietary calcium intake showed statistically significant(p ＜ 0.05) relation. Since calcium is a very important nutrient to reduce hazardous effects of lead, it should be strongly recommended that lead workers need to increase dietary calcium intake.