The RDA for zinc is 11 milligrams per day
for adult males and 9 milligrams a day for
females.
Approximately 8% of the U.S. population has
inadequate zinc intake, and up to 45% of people,
60 and older, have inadequate zinc intake.
Zinc deficiency in the U.S. is rare.
People that consume alcohol or vegetarian
may require more zinc.
Alcohol increases zinc excretion by 50%.
Vegetarians are getting their zinc from plant
sources, which has zinc bound to phytate and
lowers its bioavailability.
Vegetarians are getting their zinc from plant
sources, which has zinc bound to phytate and
lowers bioavailability.
Vegetarians may need to consume up to 50%
more of the RGA for zinc in order to get adequate
levels.
Zinc has been shown to play a role in pneumonia.
A randomized control trial in about 600 elderly
individuals, given a multivitamin that contains
zinc for 1 year found those individuals with
the highest zinc levels after supplementation
were almost 50% less likely to get pneumonia.
Another randomized control trial in hospitalized
children found that 20 milligrams of zinc
per day reduced pneumonia symptoms by 30%
compared to a placebo.
A meta-analysis of 6 randomized control trials
found that zinc supplementation in children
reduced pneumonia prevalence by 41%.
Zinc has also been shown to play a role in
the common cold.
A meta-analysis of three trials, found that
supplementation with zinc acetate loss hinges
around 80 to 90 milligrams a day found that
they had a threefold faster recovery rate
from the common cold compared to a placebo.
Another meta-analysis of seven separate trials
using either zinc acetate or zinc gluconate
lozenges found they reduced the common cold
duration by 33% compared to placebo.
Doses lower than 75 milligrams per day, have
not been shown to have an effect on the common
cold.
So let's touch a little bit on zinc and immune
function.
Studies have shown that mild zinc deficiency
may decrease immune function, including dysfunctional
cytokine production in T-cells and regeneration
not occurring in CD4+ T cells.
Multiple in vitro studies have found that
zinc inhibits the replication of RNA viruses,
but this is in vitro.
Zinc is a positively charged ion, so it cannot
get into the cell without a transporter.
But there is another way that zinc can get
into the cell without a transporter, as zinc
ionophore can help transport zinc across the
cell plasma membrane.
And this can help zinc get into the cell.
