For clarification of the effects of smoking on mineral absorption in red blood cells (RBC) and serum, their concentrations at these sites were examined in ten male smokers and 12 male and 10 female non-smokers by fluoro-X-ray analysis. K in serum was high, and P, Ca and Fe low, compared to RBC. Mg and S in serum and RBC were essentially the same. S, Mg, P and K in RBC of smokers were higher than in male non-smokers, and Ca was lower. S and Ca in serum of smokers were significantly lower than in male non-smokers. P in smokers was higher than in non-smokers. P in RBC may possibly activate the reflux of Mg into RBC and may suppress that of Ca. In smokers, the correlation coefficient (g) between Fe and Ca was r = -0.68 in RBC, and r = 0.76 in serum. Also g between P and Mg was r = 0.4 in RBC and r = -0.48 in serum. Thus Fe in RBC may suppress the reflux of Ca. Mg and Ca in serum of females were significantly higher than in male non-smokers. Ca in RBC of females was significantly higher than in male non-smokers, and P, K and Fe were significantly lower. The product of Ca and P in RBC of females was lower than in male non-smokers, while in serum it was higher. g between P and Ca, and between Fe and Ca in RBC of females were negative, while they were positive in male non-smokers. The correlations in female RBC had the same pattern as in male smokers.

        Key words: smoking, minerals, red cell, serum, fluoro-X-ray