Daily intakes of alkaline earth metals in Japanese males.

Diet samples were collected for two duplicate portion studies and one market basket study. 226Ra in the diet samples was determined by alpha spectrometry and daily intake was estimated as 23 mBq (0.62 pCi) per person. Other alkaline earth metals were determined by inductively coupled plasma atomic-emission spectrometry. Average mineral intakes of calcium, magnesium, strontium, and barium were 0.55 g, 0.21 g, 2.3 mg, and 0.39 mg, respectively. Element ratios magnesium:calcium 0.38, strontium:calcium 4.2 x 10(-3), barium:calcium 7.1 x 10(-4), and 226Ra:calcium 1.1 x 10(-12) were found in the diet; these compared with element ratios in Japanese vertebrae of magnesium:calcium 0.1:1, strontium:calcium 3.1 x 10(-4), barium:calcium 2.7 x 10(-5), and radium:calcium 2.6 x 10(-14). Observed ratios, defined as the element ratio in bone divided by the respective element intake ratio in Japanese males, were as follows: 226Ra 0.02, magnesium 0.03, strontium 0.07, and barium 0.04.