Magnesium intake and dietary sources among Koreans: findings from the Korea National Health and Nutrition Examination Survey 2016-2019

Abstract

Background/objectives: Magnesium is an essential nutrient for human health. However, inadequate intake is commonly reported worldwide. Along with reduced consumption of vegetables and fruits and increased consumption of refined or processed foods, inadequate magnesium intake is increasingly reported as a serious problem. This study aimed to assess magnesium intake, its dietary sources, and the adequacy of magnesium intake in Korean populations.

Subjects/methods: Data was obtained from the Korea National Health and Nutrition Examination Survey 2016-2019 and included individuals aged ≥1 yr who had participated in a nutrition survey (n=28,418). Dietary intake was assessed by 24-h recall, and dietary magnesium intake was estimated using a newly established magnesium database. Diet adequacy was evaluated by comparing dietary intake with the estimated average requirement (EAR) suggested in the Korean Dietary Reference Intakes 2020.

Results: The mean dietary magnesium intake of Koreans aged ≥1 yr was 300.4 mg/d, which was equivalent to 119.8% of the EAR. The prevalence of individuals whose magnesium intake met the EAR was 56.8%. Inadequate intake was observed more in females, adolescents and young adults aged 12-29 yrs, elders aged ≥65 yrs, and individuals with low income. About four-fifths of the daily magnesium came from plant-based foods, and the major food groups contributing to magnesium intake were grains (28.3%), vegetables (17.6%), and meats (8.4%). The top 5 individual foods that contributed to magnesium intake were rice, Baechu (Korean cabbage) kimchi, tofu, pork, and milk. However, the contribution of plant foods and individual contributing food items differed slightly by sex and age groups.

Conclusions: This study found that the mean dietary magnesium intake among Koreans was above the recommended intake, whereas nearly one in 2 Koreans had inadequate magnesium intake. To better understand the status of magnesium intake, further research is required, which includes the intake of dietary supplements.

Keywords: Magnesium; NHANES; Republic of Korea; dietary intake.

Fig. 1. Percentage contribution of various food groups to dietary magnesium intake of Koreans, KNHANES 2016–2019. In this analysis, food groups were classified into 20 groups as presented in Table 2. In each pie graph, the category ‘others’ means the rest of the 20 food groups, other than the top 10.

KNHANES, Korea National Health and Nutrition Examination Survey.

Fig. 2. Percentage contribution of various food groups to dietary magnesium intake of Koreans by age groups, KNHANES 2016–2019. In this analysis, food groups were classified into 20 groups as presented in Table 2. In each pie graph, the category ‘others’ means the rest of the 20 food groups, other than the top 10.

KNHANES, Korea National Health and Nutrition Examination Survey.