Calcium intake: Covariates and confounders

Abstract

One common nutrient postulated to be protective against osteoporosis, hypertension, and colon cancer is dietary calcium. We report here nutrient patterns by calcium intake in older adult residents of a geographically defined community in Southern California. The analysis included all 426 men and 531 women aged 50-79 y with complete 24-h diet data. Nutrient-density-adjusted calcium intake was divided into tertiles: low intake (< 284 mg/1000 kcal), mid intake (284-440 mg/1000 kcal), and high intake (> 440 mg/1000 kcal). The distribution of the reported 24-h nutrient density of protein, fat, fiber, caffeine, trace minerals, vitamin D, and vitamin C was examined in relation to the calcium-intake tertiles. In both men and women, the adjusted intakes of protein, saturated fatty acids, vitamin D, magnesium, and phosphorus were significantly higher in the high-calcium-intake group than in the low- and mid-calcium-intake groups. In both men and women, alcohol intake was significantly lower in the high-calcium-intake group. Studies postulating a protective role for calcium will need to consider the multicolinearity in the Western diet.