Mineral intakes of elderly adult supplement and non-supplement users in the Third National Health and Nutrition Examination Survey

Abstract

Calcium, iron and zinc are important in many of the body's functions. We report dietary and combined (diet + supplements) intakes for these minerals for elderly supplement and non-supplement users in the United States and the prevalence of inadequate intakes. We calculated usual dietary intakes for adults 60 y and older from third National Health and Nutrition Examination Survey, 1988-94; mineral intakes from supplements and calcium-containing antacids were added to usual dietary intakes. We evaluated iron and zinc intakes using the dietary reference intakes, recommended dietary allowances and estimated average requirements for elderly adults, as well as calcium intakes using the Adequate Intake and the Healthy People 2010 objective. The highest prevalences of inadequate dietary intakes was for calcium (males, 70-75%; females, 87%) and zinc (males, 35-41%; females, 36-45%). Dietary supplements improved intakes, but nearly two-thirds of elderly adults had combined intakes below the calcium objective. Non-Hispanic blacks usually had lower intakes than non-Hispanic whites and higher prevalences of intakes below the standards. Supplement users had significantly higher mean dietary intakes than non-supplement users for all three minerals for total females and non-Hispanic white females (P < 0.05 for each mineral). Many elderly adults had inadequate dietary zinc intakes, and calcium intakes fell below the Healthy People 2010 objective; dietary supplements improved intakes. Even with supplements most older adults still had intakes below the calcium objective, partly because the supplements they took usually contained low doses of calcium. Total female and non-Hispanic white female supplement users were the only groups that had higher dietary intakes than non-supplement users for all three minerals.