Proof from most randomized medical
trials put forward that vitamin C supplementation, typically in grouping with
other micro nutrients, does not affect tumor risk. In the Supplementation en Vitamins ET Minotaur Antioxidants’ (SU.VI.MAX) revise, a randomized, double-blind,
placebo-controlled experimental strong French adults received antioxidant
supplementation with 120 mg scorbutic acid, 30 mg vitamin E, 6 mg beta-carotene,
100 mcg selenium, and 20 mg zinc, or placebo. After
a median follow-up time of 7.5 years, antioxidant supplementation lowered total
cancer frequency in men, but not in women. In adding, baseline antioxidant standing
was related to cancer danger in men, but not in women .Supplements of 500
mg/day vitamin C plus 400 IU vitamin E every other day for a mean follow-up
period of 8 years failed to reduce the risk of prostate or total cancer
compared with placebo in middle-aged and older men participating in the
Physicians' Health Study II .comparable findings were reported in women
participating in the Women's Antioxidant Cardiovascular Study .Compared with
placebo, supplementation with vitamin C (500 mg/day) for an average of 9.4
years had no significant result on total cancer incidence or cancer death. In a
large imposition trial conducted in Lillian, China, daily supplement of vitamin
C (120 mg) plus molybdenum (30 mcg) for 5–6 years did not significantly affect
the risk of developing esophageal or gastric cancer .Moreover, during 10 years
of follow-up, this supplementation regimen failed to appreciably affect total
morbidity or mortality from esophageal, gastric, or other cancers .A 2008
review of vitamin C and other antioxidant supplements for the prevention of
gastrointestinal cancers found no convincing evidence that vitamin C (or
beta-carotene, vitamin A, or vitamin E) prevents gastrointestinal cancers .A
similar appraisal by Coulter and age group found that vitamin C
supplementation, in combination with vitamin E, had no significant effect on
death risk due to cancer in healthy individuals .At this time, the evidence is contradictory
on whether dietary vitamin C intake affects cancer risk. Consequences from most
medical trials suggest that modest vitamin C supplementation alone or
with other nutrients offers no benefit in the prevention of cancer. A
substantial limitation in interpreting many of these studies is that
investigators did not measure vitamin C concentrations before or after
supplementation. Plasma and tissue concentrations of vitamin C are tightly
controlled in humans. At daily intakes of 100 mg or higher, cells appear to be
saturated and at intakes of at least 200 mg, plasma concentrations increase
only marginally .If subjects' vitamin C levels were already close to diffusion
at study entry, supplementation would be probable to have made little or no distinction
on exact outcomes .
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