Estimated dietary calcium intake and food sources for adolescent females: 1980-92

Purpose: To estimate dietary calcium intake of three groups of adolescent females ages 11-12 years, 13-14 years, and 15-18 years during four separate 2-year time periods from the years 1980-92; and to identify their food sources of calcium. Methods: Nutrient intake survey based on 14-day food consumption records collected from four national representative samples of 4,000 United States households. Results: Dietary calcium consumption declined significantly (p < .01) over the 10-year period for the 15-18 year olds. Calcium intake was significantly lower for 13-14 year olds compared to the youngest age group, and for 15-18 year olds when compared to the two younger age groups for all four study periods (p < .01). Over 90% of all adolescent females consumed < 100% of the RDA for calcium during all data collection periods. The percentage of adolescent females who consumed less than two- thirds of the RDA increased with age. Seventy-seven percent of 15-18 year olds consumed below this level from 1990-92. Milk and milk products were the best food sources of calcium contributing over one-half of the calcium to the diet. This percentage declined over time and with age to 44% for the 15-18 year old females in 1990. This drop can be attributed to a 7-12% decline in fluid milk consumption for the 11-12 year olds and 15-18 year olds, respectively. Conclusions: Estimates indicate that dietary calcium intakes fall far short of both the Recommended Dietary Allowance (RDA) and National Institutes of Health (NIH) recommendations. Intakes have declined over time, with age, and appear to be related to a decline in fluid milk consumption. Efforts to increase calcium consumption among adolescent females appear critical. Clear recommendations to consume a minimum of three servings everyday of lowfat or nonfat dairy products such as milk and yogurt are needed to help this population meet daily calcium requirements.