Background: Calcium is one of the essential micronutrients in the human body and is well-known for its important role in keeping bones and teeth healthy. However, calcium deficiency is a very common nutritional problem in the world and especially in China. The aim of this research was to determine the dietary calcium intake of Chinese adults and the corresponding food sources based on data from the 2015 China Nutritional Transition Cohort Study.
Methods: We obtained dietary data from Chinese adults ages 18 to 64 years in 15 provinces, autonomous regions, and municipalities using 3 consecutive days combined with the household weighing method. We used the China Food Composition (book 1, 2nd edition) to calculate the calcium intake from each food category. We regarded the percentage of participants with a calcium intake median below the estimated average requirement as the level of calcium inadequacy in the overall population.
Results: We divided the participants into 2 age groups, 18-49 years and 50-64 years, which included 6,630 and 5,307 participants, respectively. The groups' dietary calcium intake medians were 324.8 milligrams per day (mg/d) and 332.7 mg/d, respectively, and the calcium inadequacies were 92.9% and 96.0%, correspondingly. The median calcium intake for the whole study population was 328.3 mg/d, and the inadequacy was 94.3%, which improved with higher education, income, and urbanization levels. The main food sources of dietary calcium among the study population were vegetables, legumes, and cereals, which contributed 30.2%, 16.7%, and 14.6%, respectively. Milk and dairy products contributed 6.7% to the study population but varied with the urbanization level to 15.0%, 6.1%, 6.3%, and 2.0% in urban, suburban, county, and rural areas, respectively.
Conclusion: These findings highlight the importance of nutrition education and intervention for Chinese adults to improve their dietary structures and increase milk and dairy products intake to consume adequate calcium.