Ten-year trends in dietary vitamin D intake and its food sources among Koreans: based on the 2013-2022 Korea National Health and Nutrition Examination Survey data.

Background/objectives: This study analyzed 10-yrs trends in dietary vitamin D intake and its food sources among Koreans.

Subjects/methods: This study included 61,734 individuals (≥ 3 yrs) from the 2013-2022 Korea National Health and Nutrition Examination Surveys. Daily vitamin D intake was assessed based on 24-h recall data. 10-yrs trends in 1) vitamin D intake, 2) vitamin D intake relative to the adequate intake (AI) of 2020 Dietary Reference Intakes for Koreans, and 3) proportions of individuals whose vitamin D intake below and above AI were analyzed using a complex sampling general linear model. Changes in food sources of vitamin D was also determined.

Results: Vitamin D intake significantly decreased over 10 yrs with 3.2 μg/d in 2013 and 2.9 μg/d in 2022 (P-trend = 0.003) among Koreans. A significant decreasing trend was observed in males (3.6 μg/d in 2013 to 3.1 μg/d in 2022; P-trend = 0.002) but not in females. The average percentage of vitamin D intake relative to the AI decreased from 34.1% in 2013 to 30.9% in 2022 (P-trend = 0.003). The proportion of individuals whose vitamin D intake was below the AI increased from 93% in 2013 to 95% in 2022 (P-trend < 0.001). In 2022, the main food sources were eggs, squid, soy milk, salmon, mackerel, and pork, with increased contributions from eggs, soy milk, and pork than that in 2013.

Conclusion: Vitamin D intake among Koreans has declined significantly over the past decade. Developing effective dietary guidelines considering sex and age is essential to improve vitamin D intake in this population.