Usual Intake of Micronutrients and Prevalence of Inadequate Intake among Chinese Adults: Data from CNHS 2015-2017

Previous studies have used the traditional average-value method to calculate the usual dietary intake of a population, but the results may be biased due to the measurement errors. The aim of this study was to provide an assessment of the usual micronutrient intake and estimate the prevalence of inadequate intake among Chinese adults. Data from the Chinese Nutrition and Health Surveillance 2015-2017 as well as a total of 72,231 subjects aged 18 years and older were included in the analysis. The 24 h recall method combined with the condiment weighing method were used for three consecutive days to collect daily food and condiments intake. The daily intake of 16 micronutrients was calculated based on the Chinese Food Component Tables. The National Cancer Institute (NCI) method was used to estimate the usual intake of micronutrients, and the prevalence of inadequate intake was estimated using the estimated average requirement (EAR) cut-point method. The results showed that, except for sodium, copper, iron (only for males), vitamin E, and phosphorus, the usual intake of micronutrients in Chinese adults was low, and the prevalence of inadequate intake ranged from 38.67 to 97.63%. The prevalence of inadequate calcium and riboflavin intake was more than 90%, and the proportion of individuals with a usual intake of thiamine, vitamin A, potassium, and selenium below EAR also reached 80%. Manganese, magnesium, vitamin C, and zinc were potentially deficient micronutrients, with the prevalence of inadequate intake ranging from 38.67% to 77.09%. However, usual sodium intake was extremely high with an average of 5139.61 mg/day, and only a quarter of Chinese adults were below the World Health Organization (WHO) recommended value. For most micronutrients, the usual dietary intake declined with age and the prevalence of inadequate intake increased with age. Except for zinc, vitamin A, and B-vitamins, the prevalence of micronutrient deficiencies was higher in females than in males in the same age group (p < 0.05). Therefore, Chinese adults do not receive enough micronutrients. Effective nutrition supplementary strategies and measures are needed to address these problems.