Calcium Intake in the United States from Dietary and Supplemental Sources across Adult Age Groups: New Estimates from the National Health and Nutrition Examination Survey 2003–2006

Background Adequate lifelong calcium intake is essential in optimizing bone health. Recent National Health and Nutrition Examination Survey data were used to quantify variation in calcium intake across adult age groups and to relate age-associated changes in calcium intake with energy intake. Additional goals were to assess differences in dietary calcium intake between supplemental calcium users and nonusers and to evaluate associations between age and calcium density in the diet. Design This cross-sectional analysis determined calcium and energy intake for National Health and Nutrition Examination Survey respondents during 2003–2006. Diet was assessed with 24-hour recall and supplement use via questionnaire. Trends in median intakes for dietary calcium, total calcium, and energy across age categories were assessed using survey analysis methods. Nutrient density was represented using calcium to energy intake ratios. Results The analyses included data from 9,475 adults. When compared to the 19- to 30-year age group, median dietary calcium intake was lower in the ≥81-year age group by 23% in men (P\u3c0.001) and by 14% in women (P=0.003). These reductions coincided with 35% and 28% decreases, respectively, in median energy intake (P\u3c0.001 for each sex). In contrast, the frequency of calcium supplement use increased (P\u3c0.001) with age in both men and women. Yet, among female supplement users, the decline in median dietary calcium intake was greater than in nonusers (P=0.02). Calcium density in the diet significantly increased relative to age in men and women (P\u3c0.001 for each sex); however, dietary and total calcium to energy ratios were insufficient to meet target ratios inferred by adequate intake standards after age 50 years. Conclusions Although supplemental calcium use and calcium density were highest in older age groups, they were not sufficient in meeting recommended levels. New approaches to increasing the frequency and level of calcium supplement use to enhance calcium density in diets may be necessary to reduce osteoporosis risk among older Americans