welcome to another video on vitamin d this one's going to be about vitamin d as it pertains to
covid 19 so vitamin d has been maligned and praised throughout 2020 and into 2021
as a cheap supplement that nearly everyone has access to why is it getting so much attention
well there's lots of studies that show a strong association between vitamin d deficiency and
increased numbers in severity of respiratory infections not just covid these studies
show a relationship between vitamin d supplements in covid 19 not that vitamin d deficiency causes
covid 19 and this distinction is important because a third variable may actually be responsible for
the effect imagine you're studying 100 people who have doubled the number of respiratory infections
per year compared to the baseline population they all have low levels of vitamin d is having low
levels of vitamin d the cause of their increased risk of respiratory infections maybe they live
in a crowded understaffed nursing home they don't get outside and they eat a poor diet
these factors could explain the increased risk for infection and the low vitamin d levels but you
wouldn't know that unless you're looking for it or you structured your study to remove the effects
of other variables that are not measured here are five studies that support the relationship between
vitamin d deficiency and more severe respiratory diseases researchers in germany followed almost
10 000 adults aged 50 to 75 for 15 years to evaluate their mortality from respiratory diseases
among these study participants 44 had low vitamin d levels and 15 were vitamin d deficient overall
after adjusting for sex age the season of the blood draw school education bmi physical activity
and fish consumption 41 of respiratory disease mortality was statistically because of low
vitamin d levels there's also a meta-analysis published in the british medical journal in 2017.
i've done a video on this before but in that study they reviewed 25 randomized double-blinded control
trials that had over 11 000 participants now vitamin d supplements reduced each individual's
risk by at least one respiratory infection when all the results were averaged together there was
a slight protective effect while daily in weekly doses of vitamin d reduced risk single large doses
of vitamin d did not protective effects of vitamin d they were greatest in those with the lowest
vitamin d levels now in a retrospective study in 2020 quest diagnostics in the united states
they looked at the labs for vitamin d levels and sars cov2 positivity for almost 200 000 people the
authors they found a strong inverse relationship between vitamin d levels and sars positivity
that persisted across latitudes races ethnicities sexes in age ranges they found the risk of being
positive for styroscopy 2 was 1.6 lower with each vitamin d increase by 1 ng per ml there's
a previous study that showed that for every 4 ngs per ml increase in vitamin d there was a seven
percent decrease in risk for seasonal respiratory infections when researchers at the university of
chicago medicine reviewed the health records of almost 500 people who had vitamin d testing within
the previous year they found that the relative risk for testing positive covid 19 was 1.77
times greater for vitamin d deficient patients but compared to those who were not two-thirds
of the study participants were non-white and 47 percent had a bmi greater than or equal to 30
which is considered obese although the results were significant this was a retrospective study
and there may be unknown confounding variables that increase the risk for both vitamin d
deficiency and covid 19. another study published in nature examined the health records of over 17
million adults of which 10 000 had died of covid 19 risk factors including being male older age
having diabetes asthma obesity or other medical conditions and having darker skin color supporters
for giving vitamin d point out that older age obesity and having darker skin color are risk
factors for both covid 19 and vitamin d deficiency and critics state that other variables may have
had a greater effect what can these studies tell us there seems to be a fairly strong relationship
between vitamin d deficiency in the number and severity of respiratory infections including covet
the quest diagnostic study and the one from the university of chicago indicate that yes
your risk of getting a covid 19 infection increases as your vitamin d level decreases like
wearing masks social distancing avoiding crowds and poor ventilation and vaccination if you're
vitamin d deficient it's a correctable risk factor that you can do something about to prevent covid 19
infection of course none of these preventative methods is 100 protective but they can all help
if you're not vitamin d deficient then taking vitamin d supplements isn't going
to affect your risk for covid 19 infections but the other preventative measures will
the german study that i referenced earlier suggests that 41
of respiratory disease mortality is statistically attributable to vitamin d deficiency or
insufficiency this study supports the use of vitamin d to ease covid 19 severity to answer
these questions more fully there are currently 40 ongoing interventional trials with vitamin d
and covid 19 worldwide a recent study conducted in barcelona was published as a pre-print which is
a non-peer-reviewed study available for review and comment before publication in a journal
that barna cova dial study reported that when vitamin d was given to
patients hospitalized with covid 19 the mortality rate decreased by 60 percent
it was the first and largest study to directly evaluate the impact of calcifidiol vitamin d3
these supplements on covid 19 mortality and icu admission here is the data from the study group
now these results appear to be overwhelmingly in support of vitamin d supplements
the pre-print results led david davis an advocate for vitamin d usage and a british politician to
call for the widespread vitamin d supplementation citing the causal relationship between increased
vitamin d levels and decreased mortality shown in the study he advocated that the uk government
increased the recommended dose and distribute free vitamin d to all vulnerable groups he urged
doctors to treat every covid patient in every hospital in temperate climates with vitamin d
this study shows strong support for adding vitamin d supplements to treat severe covenanting
do we have all the evidence we would like to make this claim no now other people have been
more skeptical about these results and in fact several concerns with the study's methodology
caused it to be withdrawn by the lancet as a pre-print and sent back to the investigators
for clarification and to address problems with the investigation including that the trial wasn't
registered with clinicaltrials.gov now registering the study makes investigators openly state their
plans and review criteria up front also it wasn't a randomized control study the gold standard for
scientific studies it used clustering instead of randomization also the statistical method used
was not appropriate for a study that used clusters and males and females were not evenly distributed
between the control and experimental groups and also there are 551 people in the treatment group
and 359 in the control group so there is an uneven distribution also the baseline vitamin d levels
were 15 ng per ml in the treatment group and 12 ng per ml in the control group this difference in
baseline vitamin d levels could have significantly affected the study results a study by uk biobank
recruited over 500 000 people between 2006 and 2010. baseline data on exposure to covid 19
vitamin d levels and ethnicity were linked to covid 19 results after adjusting for confounding
variables researchers found no association between vitamin d levels and the risk for covid 19
infection critics state that participants may have taken vitamin d supplements in the years between
when vitamin d levels were obtained and then exposure to covid 19 infection a
study that is not yet peer reviewed enrolled 240 hospitalized patients in a multi-center
double-blinded randomized placebo-controlled trial and two centers in brazil study participants
received a single oral dose of 200 000 ius of vitamin d3 or placebo the study found that vitamin
d levels increased in the treated patients but had no effect on hospital length of stay mortality
admission to the icu or need for mechanical ventilation now critics would point to a single
large dose as the reason that no effect was seen when 137 study participants in the uk
either received a single large dose of vitamin d along with a daily low dose versus placebo there
was no difference between the two groups in terms of number or severity of respiratory infections
critics of this study state that the timing of the vitamin d levels
in the single large dose of vitamin d were problematic the nih recommendation states that
there is insufficient data to recommend either for or against vitamin d to prevent or treat covid 19
there are several unknowns regarding vitamin d and immune health the optimal level of vitamin d for
bone health has been well studied but the optimal level for immune health has not blood vitamin d
levels may not adequately represent tissue levels because it's possible that you have tissue levels
within your cells that are different from the amount that you have in your bloodstream
so how much vitamin d should people take well the endocrine societies recommend that most
adults 19 years and older should get around 400 to 1000 international units meaning ius
of vitamin d daily from food and or supplements the nih and endocrine societies recommend that
adults 50 to 70 require at least 600 ius per day and those over the age of 70 get at least 800 ius
per day it's also recommended that for populations at risk for vitamin d deficiency who are age 80 or
older should get 6 000 ius per day under medical supervision in order to reach a level that's above
30 ngs per ml followed by a maintenance dose of 1500 to 2 000 ius per day otherwise populations
at risk should receive the rda of 600 ius per day with an upper limit of 4 000 iu's per day
obese individuals over the age of 8 should receive 4 000 ius per day and as high as 10 000 iu's per
day under medical supervision may be needed for obese adults to correct vitamin d deficiency
vitamin d levels can vary by type of measurement and by the organization so quest diagnostics they
list optimal vitamin d levels as 30 to 100 ngs per ml and 20 to 29 is considered sub-optimal
and levels less than 20 ngs per ml are vitamin d deficient the nih classifies adequate levels as
being 20 to 50 ngs per ml inadequate if it's 12 to 20 and then vitamin d deficient if it's less
than 12 once you start getting to levels more than 50 ngs per ml that's where you have the
potential for adverse effects especially when you start getting to levels of 150 ngs per ml
vitamin d deficiency it doesn't have any symptoms so the only way to know if you're deficient is by
getting a blood test many insurance companies even medicare they don't cover vitamin d levels
unless you have a medical condition that puts you at high risk of having vitamin d deficiency
for example chronic kidney disease in a study done in the united states about
40 percent of about 5 000 people over the age of 20 were vitamin d deficient
another study found that the overall prevalence rate of vitamin d deficiency was 42
with the highest rate in blacks at 82 percent followed by hispanics at 69 percent at 40 degree
latitude there's virtually no vitamin d effective uv radiation in december january and february
at 90 degree latitude there's no vitamin d effective radiation for 8 of the 12 months
anyone living above the 35th parallel which cuts through the middle of the united states
will not get enough vitamin d in the winter because the sun's angle with the earth is too
great even in the summer you may be at risk for vitamin d deficiency as a survey showed
that americans spend only 7.6 percent of their time outdoors aging increased skin
pigmentation a diet high in fructose corn syrup and obesity can lead to decreased vitamin d levels
in the middle of winter most people in the u.s are likely to be vitamin d deficient this is a
convincing argument to take vitamin d supplements especially if it may decrease your risk of
respiratory infections however it is possible to overdose on vitamin d but this is really hard to
do excess vitamin d is toxic vitamin d increases the absorption of calcium from the gi tract
excessive calcium in the blood that can lead to nausea vomiting muscle weakness neuropsychiatric
disturbances pain loss of appetite dehydration excess of urination and thirst and kidney stones
in extreme cases excessive vitamin d can cause kidney failure heart rhythm abnormalities and
death although i gotta say again this is extremely rare and hard to do there was a
case report from 2019 that described the person who suffered kidney damage from excess vitamin d
in a more recent case in ohio a patient took vitamin d to treat covid 19
leading to several medical issues dr oppermann his physician
he said that quote high calcium levels from high dose vitamin d that can lead to confusion kidney
stones and ultimately hospitalization in this situation ultimately whether vitamin d helps
prevent infection reduces disease progression or decreases mortality in patients with covid 19
it's unknown so it's best to either take vitamin d following the recommended daily allowances or
speak with your doctor about an increased dose if you might be vitamin d deficient