[Status and trends in dietary vitamin intakes of adults aged 18 to 35 in 15 provinces (autonomous regions, municipalities) of China during 1989-2015].

Objective: To analyze the status and long-term trends in dietary vitamin intakes from 1989 to 2015 in adults aged 18 to 35 in 15 provinces(autonomous regions, municipalities) of China.

Methods: Based on the data of "China Health and Nutrition Surveys" from 1989 to 2015 and "cohort study on the changes of nutritional status of Chinese residents" in 2015, covering 15 provinces(autonomous regions, municipalities) in China. Adults aged 18 to 35 were selected as study subjects. Nonparametric statistical method was used to analyze the trend of dietary vitamin intake with years. Comparing the dietary vitamin intake with the dietary reference intakes, the trend of the proportion of people at risk of insufficient dietary vitamin intake was analyzed by Cochran Armitage trend test. According to the different demographic characteristics in 2015, the vitamin intake status and the proportion of people with insufficient dietary vitamin intake were analyzed.

Results: From 1989 to 2015, the overall dietary vitamin intake of adults aged 18-35 in 15 provinces(autonomous regions, municipalities) of China showed a downward trend. The median vitamin intake of adults in 2015 were vitamin A 361. 28 μg RAE/d(based on vitamin A activity equivalent), vitamin B_1 0. 75 mg/d, vitamin B_2 0. 67 mg/d, nicotinic acid 13. 61 mg/d, vitamin C 56. 41 mg/d and vitamin E 21. 04 mg α-TE/d. In 2015, there were significant differences in dietary vitamin A, vitamin B_2, niacin and vitamin C intakes between the North and the South and the distribution of education level, in which the intakes of vitamin A, vitamin B_2, niacin and vitamin C in the South were significantly higher than those in the North; the intakes of dietary vitamin B_1 in the low education level group were significantly lower than those in the middle and high education level; the intakes of dietary vitamin B_1 in urban areas were significantly higher than those in the North. The intakes of vitamin A, vitamin B_2, niacin and vitamin E were significantly higher than those in rural areas. From 1989 to 2015, the proportion of people with insufficient intake of vitamin B_2 remained above 80%, and the proportion of adults with the risk of insufficient intake of dietary vitamin A, vitamin B_1 and vitamin C showed an increasing trend year by year. In 2015, the proportion of people at risk of insufficient intake of dietary vitamin A, vitamin B_2 and vitamin C in northern China was significantly higher than that in southern China.

Conclusion: From 1989 to 2015, there was a risk of insufficient intake of micronutrients in adults aged 18-35 in 15 provinces(autonomous regions, municipalities) in China, and the problem of insufficient calcium intake was serious.