ERYTHROCYTE AND PLASMA B-6 VITAMER CONCENTRATIONS OF LONG-TERM TOBACCO SMOKERS, CHEWERS, AND NONUSERS

Erythrocyte and plasma B-6 vitamer concentrations were determined in m ales aged 25-55 y who were long-term smokers, chewers, or nonusers. To bacco users had either smoked (n = 23) or chewed (n = 11) for > 15 y; nonusers (n = 11) had never smoked or chewed. All subjects had normal hematocrit values. Food energy, protein, and vitamin B-6 intakes of th e three groups of subjects were not significantly different. All subje cts had fasting plasma pyridoxal-5'-phosphate (PLP) concentrations ind icative of adequacy. Erythrocyte B-6 vitamer and 4-pyridoxic acid (4-P A) concentrations of all three groups were not significantly different . Nonusers had significantly higher plasma PLP concentrations than did smokers, whereas PLP concentrations of chewers were intermediate betw een the two groups. Chewers had significantly higher concentrations of plasma pyridoxamine-5'-phosphate (PMP) than other groups. Plasma pyri doxal, pyridoxine, pyridoxamine, and 4-PA concentrations of the three groups were not significantly different. Differences in some B-6 vitam er concentrations in plasma but not in erythrocytes were observed betw een tobacco users and nonusers.