Voldoende
vitamine C belangrijk om vet te verbranden.*
Zij
die weinig vitamine C in hun bloed hebben verbranden tijdens inspanning veel
minder vet dan zij die goede bloedwaarden vitamine C hebben. Wellicht is dit een
verklaring waarom bepaalde mensen tijdens inspanningen geen vet verliezen en
andere duidelijk wel. Vitamine C is een co-factor voor de aanmaak van carnitine
en deze stof is nodig om vetzuren te verbranden.
Marginal
vitamin C status is associated with reduced fat oxidation during submaximal
exercise in young adults
Abstract
(provisional)
The
complete article is available as a provisional
PDF. The
fully formatted PDF and HTML versions are in production.
Background
Vitamin
C is a cofactor in the biosynthesis of carnitine, a molecule required for the
oxidation of fatty acids. A reduction in the ability to oxidize fat may
contribute to the reported inverse relationship between vitamin C status and
adiposity. To examine this possibility, we conducted a preliminary trial to
evaluate the impact of vitamin C status on fat oxidation during submaximal
exercise.
Methods
Fat
energy expenditure was determined in individuals with marginal (n=15) or
adequate (n=7) vitamin C status during a submaximal, 60-minute treadmill test.
Subsequently, eight of the subjects with marginal vitamin C status completed an
8-week double-blind, placebo-controlled, depletion-repletion trial with
submaximal exercise testing.
Results
Individuals
with marginal vitamin C status oxidized 25% less fat per kg body weight during
the treadmill test as compared to individuals with adequate vitamin C status.
Fat oxidation during exercise was inversely related to fatigue (r=-0.611,
p=0.009). Vitamin C repletion of vitamin C depleted subjects (500 mg vitamin
C/d) raised fat energy expenditure during exercise 4-fold as compared to
depleted control subjects (p=0.011).
Conclusion
These
preliminary results show that low vitamin C status is associated with reduced
fat oxidation during submaximal exercise. Low vitamin C status may partially
explain the inverse relationship between vitamin C status and adiposity and why
some individuals are unsuccessful in their weight loss attempts.
(Sept. 2006) (Opm. Veel groenten en fruit geven een goede bloedwaarde vitamine C kijk maar eens bij ABC.)