Dietary Intake and Urinary Excretion of Manganese in Korean Healthy Adults

Manganese (Mn) is an essential element for the body’s composition and is required for various functions, including nutrient metabolism, immune system function, and antioxidant ability. However, there are insufficient data on the nutritional status of Mn. In this study, we aimed to analyze the relationship between Mn intake and urinary excretion in Korean adults. A twice dietary intake survey using a 24-h recall method was conducted on 640 adults (320 men and 320 women), aged 20 to 69 years. Eighty 24-h urine samples were also twice collected and urinary Mn excretions were analyzed. Results indicated that total Mn intake per day was 4.1 mg for men and 3.9 mg for women (p < 0.05). Mn intake per 1000 kcal of energy consumption was significantly higher in women than in men (2.0 mg/1,000 kcal vs. 2.2 mg/1000 kcal, p < 0.01). Additionally, Mn intake as a percentage of Adequate Intake was 103.0% for men and 110.3% for women (p < 0.05). Mn was mostly consumed from cereals (1.78 mg/day for men and 1.53 mg/day for women), followed by vegetables, seasonings, fruits, and pulses. The main food sources of Mn were rice (27.8% for men, 22.0% for women), kimchi (3.5% for men, 1.4% for women), and tofu (2.8% for men, 2.3% for women); the percentage of Mn consumed from 20 types of foods was 55.6% (women) to 60.4% (men). Urinary Mn excretion was negatively correlated with Mn intake from cereals and positively with mushrooms only for women after adjusting for confounding factors (p < 0.05). In conclusion, dietary Mn intake by Korean adults was adequate to meet the Dietary Reference Intake, but the relationship between Mn intake and urinary excretion was not clear.