- The present study was designed to investigate the
effects of exercise on vitamin B-6 metabolism. Four groups
of subjects (intermittent, college, untrained, and high school)
consisting of nineteen male and two female individuals, participated
in the study. The subjects exercised either on a
bicycle ergometer, by running three 1500 meter intervals, or
both. Blood samples drawn prior to exercise (pre), after exercise
(post), and 30 minutes after exercise (30 minute post),
were analyzed for plasma pyridoxal 5'-phosphate (PLP), plasma
B-6 (PB6), glucose, hemoglobin and hematocrit. A 24-hr urine
collection the day before and the day of exercise was analyzed
for urinary B-6 (UB6), 4-pyridoxic acid (4PA), creatinine, and
The dietary intake of the four groups was greater than the
RDA in vitamin B-6, riboflavin, thiamin, niacin, vitamins A and
C, calcium and iron. The B-6/protein ratios of the college and
untrained groups were adequate while the high school group's
ratios were considered inadequate.
The bicycle ergometer had a significant effect on the plasma
PLP levels of the college and untrained groups (P< 0.005) and PB6
levels of the college group following exercise (P< 0.005). The
30 minute post plasma PLP levels were significantly lower for
the college group (P< 0.005).
During the run, the college group had significantly higher
post exercise levels of plasma PLP (P< 0.005) and PBS (P< 0.005}
as compared to the pre exercise sample. The high school group
also had significantly higher levels of plasma PLP following,
exercise for all three runs (P< 0.005, P< 0.025, and P< 0.01,
respectively) as well as higher PB6 levels (P< 0.025, P< 0.01,
and P< 0.025, respectively).
The college athletes had a greater percent change in plasma
PLP (P < 0.01) from the pre to post sample during the run as
compared to the high school athletes.
Urinary B-6 and 4PA were not significantly altered during
either exercise suggesting a shift in PLP and the unphosphorylated
forms of vitamin B-6 from one compartment to another. The significantly
higher levels of plasma PLP and PB6 following exercise
were attributed to an increased utilization of glycogen phosphorylase
in the skeletal muscle with a subsequent release of PLP.