Bioavailable zinc intake of Korean adults in relation to the phytate content of Korean foods

Abstract

This study was conducted to create a phytate database for food items and to evaluate the bioavailability of zinc in Korean adults. Eighty-seven food items were analysed. Phytate content was determined by ion exchange method and zinc bioavailability was assessed through a dietary survey of 841 adults. Measured phytate values in various groups were as follows: 191.7–973.3 mg in cereals, 508.5–1371.8 mg in legumes, 0.4–319.9 mg in vegetables, and 1–50 mg in fruits. Mean zinc intakes of Korean adults (9.5 mg for male and 7.5 mg for female subjects) were less than the Korean recommended dietary allowance. Cereals (68.6%) and legumes (19.3%) supplied the most dietary phytate. Mean phytate:zinc ratios were 9.5 for males and 10.5 for females. High zinc bioavailability (phytate:zinc molar ratio below 5) occurred in 9.6% of subjects, whereas 13.2% had low bioavailability (molar ratio over 15). Below-normative zinc intake levels occurred in 54.3% of subjects (61.8% for male and 49.5% for female). Further studies should be directed towards increasing zinc intake and enhancing bioavailability to improve zinc status in Korea.