Recent research regarding vitamin B₆ status including biochemical index is limited. Thus, this study estimated intakes and major food sources of vitamin B₆; determined plasma pyridoxal 5'-phosphate (PLP); and assessed vitamin B₆ status of Korean adults.

Three consecutive 24-h diet recalls and fasting blood samples were collected from healthy 20- to 64-year-old adults (n = 254) living in the Seoul metropolitan area, cities of Kwangju and Gumi, Korea. Vitamin B₆ intake and plasma PLP were analyzed by gender and by vitamin B₆ supplementation. Pearson's correlation coefficient was used to determine associations of vitamin B₆ intake and plasma PLP.

The mean dietary and total (dietary plus supplemental) vitamin B₆ intake was 1.94 ± 0.64 and 2.41 ± 1.45 mg/day, respectively. Median (50th percentile) dietary intake of men and women was 2.062 and 1.706 mg/day. Foods from plant sources provided 70.61% of dietary vitamin B₆ intake. Only 6.3% of subjects consumed total vitamin B₆ less than Estimated Average Requirements. Plasma PLP concentration of all subjects was 40.03 ± 23.71 nmol/L. The concentration of users of vitamin B₆ supplements was significantly higher than that of nonusers ( P < 0.001). Approximately 16% of Korean adults had PLP levels < 20 nmol/L, indicating a biochemical deficiency of vitamin B₆, while 19.7% had marginal vitamin B₆ status. Plasma PLP concentration showed positive correlation with total vitamin B₆ intake (r = 0.40984, P < 0.0001).

In this study, vitamin B₆ intake of Korean adults was generally adequate. However, one-third of subjects had vitamin B₆ deficiency or marginal status. Therefore, in some adults in Korea, consumption of vitamin B₆-rich food sources should be encouraged.