"Vitamin D Supplements Tested for COPD, Heart Disease, Depression, Obesity, and Cancer Survival"
Many health benefits have been attributed
to having higher vitamin D levels in the blood.
Examples include reduced risk of musculoskeletal disorders,
infectious diseases, autoimmune diseases, cardiovascular disease,
diabetes, several types of cancer, neurocognitive dysfunction,
adverse pregnancy and birth outcomes,
and all-cause mortality.
But most such attributions are based on observational studies,
meaning just drawing correlations between the two.
And having high vitamin D levels may just be a marker of good health.
After all, vitamin D is the sunshine vitamin.
Who has higher levels of vitamin D in their blood?
People who run around outside, so maybe the D is just a marker
for exercise and that's really what's lowering disease risk.
And indeed, when vitamin D supplements
are actually put to the test in randomized controlled trials,
they often fail to support a direct vitamin D benefit.
In this video, I'm going to explore the randomized controlled trial data
on vitamin D supplementation for COPD --
chronic obstructive pulmonary diseases like emphysema,
critical illness, like whether we should be giving vitamin D
to people in the ICU,
cardiovascular disease, like heart attacks and strokes,
preventing depression, treating depression,
vitamin D for weight loss,
and vitamin D for lung cancer survival, prostate cancer survival,
and colorectal cancer survival.
What do you think?
Do you think vitamin D supplements will help with some of them,
all of them, none of them?
Let's find out.
"The efficacy of vitamin D therapy for patients with COPD:
a meta-analysis of randomized controlled trials"
found that compared to placebo,
vitamin D can improve lung function, improve six-minute walk distance,
and reduce acute exacerbation, sputum volume,
and COPD assessment test scores.
In other words, so far, so good.
Vitamin D supplements are effective for treating COPD.
What about vitamin D supplementation for critically ill adult patients?
If your loved one ends up in the ICU for whatever reason,
should you try to press the doctors to give them a vitamin D boost?
Overall, nine randomized controlled trials involving nearly 2,000 patients
were included, and no significant difference in mortality was observed.
Okay, so, so far D is one for two.
What about cardiovascular disease?
Widespread fascination with vitamin D as a panacea
is responsible for nearly a 100-fold increase
in vitamin D testing and supplementation
over the last decade, and no wonder.
Follow people over time, and there is an unequivocal association
between low vitamin D status and people's risk of getting and dying
from our leading killer, cardiovascular disease.
But is it cause-and-effect?
Maybe low vitamin D levels are a result of cardiovascular disease
rather than the cause.
If you have chest pain,
you're probably not out in the sun running around.
That's why there's been more than 20 randomized controlled trials
to put vitamin D to the test, and no benefit for heart attacks,
no benefit for strokes, no benefit for mortality.
The good news, of course, is that heart disease is preventable,
is reversible but requires significant cleaning up of your diet.
What about vitamin D for preventing depression?
Among older adults, five years of vitamin D supplementation
had no effect on the occurrence of depression or change in mood scores.
These findings do not support the use of D to prevent depression.
What about treating depression?
Every single one of the trials
for patients suffering from major depression
found a benefit to vitamin D supplementation over placebo,
though more is not necessarily better,
and it may take a few months for it to kick in.
Let's see how we're doing on the scoreboard.
Obesity is next.
"Effects of Vitamin D Supplementation on General and Abdominal Obesity:
Results from 20 Randomized Controlled Trials" show no significant effect
on the measures of obesity, including BMI, waist circumference,
or waist to height ratio.
Treating cancer is up next.
"Vitamin D Supplementation and Survival of Patients with..."
the most common type of lung cancer.
In early-stage lung cancer,
all you can do is try cutting out the primary tumor,
but despite adding chemo, tumor relapse rates remain high.
Surgeons noted that patients who had surgery during the summer
seemed to do better than those in the winter,
which was chalked up to higher vitamin D status.
So they randomized patients to 1200 international units
of vitamin D a day or placebo,
and over the next few years: no significant difference
in either relapse-free survival or overall survival was seen
with vitamin D compared with the placebo group.
But that was in the total study population.
What if you just looked at the patients
who started out with low vitamin D levels?
In that case, there did appear to be a benefit
from D supplementation.
Among those starting out with D levels
under 20 nanograms per milliliter
(which is equivalent to 50 nanomoles
per liter -- depends which units your lab uses),
half of those who took the placebo relapsed and half died.
But those who started with low levels
and were treated with actual vitamin D,
86% remained in remission and 91% remained alive.
What about "The Effect of Vitamin D Supplementation on Prostate Cancer:
A Systematic Review and Meta-Analysis of Clinical Trials"
found that there were no significant differences in total mortality
between participants receiving vitamin D supplementation
and those receiving placebo.
That brings us to here, though again,
note the lung cancer benefit
was only seen in those who started out with low levels.
And vitamin D supplementation for colorectal cancer survival?
Yes!
A systematic review and meta-analysis
of randomized controlled trials found that supplementation
imparts a 30% reduction in bad outcomes overall,
with a 24% reduction in the risk of dying
specifically from your colorectal cancer,
and a third lower risk of disease progression or death from any cause.
The optimal dose for this survival benefit remains unclear
since the trials used different doses, but it looks like
between 2000 and 4000 international units a day is a good place to start.