This investigation was designed to add to present understanding
of vitamin B-6 (B6) metabolism during exercise. Ten women, 5
aerobically trained and 5 untrained, were fed 4 controlled diets: a
moderate carbohydrate (49%) (MCHO) for 2 weeks, a high carbohydrate
(63%) (HCHO) for one week, MCH0+B6 for 2 weeks, and HCH0+B6 for 1
week. A one week MCHO diet separated the non-supplemented (2.3 mg
B6) and supplemented (10.3 mg B6) diets.
The V02 max of each subject was determined prior to the study.
An exercise test was completed on day 5 or 6 of weeks 2, 3, 6, and
7. The test consisted of 20 minutes of cycle ergometer exercise at
80% V02 max, preceded by 10 minutes of warm-up and followed by a 5-10
minute active recovery. Blood samples were collected pre exercise
(pre), 2-3 minutes post (post), 30 minutes post (p30), and 60
minutes post (p60) exercise. Samples were analyzed for plasma
vitamin B-6 (PB6), hematocrit, and hemoglobin. Urine was collected daily in 24-hr aliquots and samples were analyzed for 4-pyridoxic
acid (4PA) and creatinine.
For all diets, exercise resulted in a significant increase in
PB6 from pre to post and a significant decrease from post to p60,
the magnitude of the change being greater with supplementation. PB6
fell below pre levels by p60 for all exercise sessions. 4PA
increased significantly from the day before exercise to the day of
exercise on all diets. There was no significant effect of dietary
carbohydrate on levels of PB6 or excretion of 4PA. ANOVA showed no
difference between the groups for PB6 or 4PA, though the trained
group had lower PBS and greater 4PA excretion throughout the study
despite the controlled intake.
Tissue redistribution of B6 seems to occur with exercise. The
increased magnitude of change in PB6 with exercise after
supplementation suggests an increased storage of the vitamin, most
likely associated with glycogen phosphorylase in the muscle.
Trained women may have lower levels of PB6 and greater 4PA excretion
as the result of a regular exercise program. However,
supplementation with B6 cannot be recommended since the status of
all subjects was adequate with the diet fed. / Graduation date: 1985
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/27178 |
| Date | 10 August 1984 |
| Creators | Walter, M. Carol |
| Contributors | Leklem, James E. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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