vitamin d3 cholecalciferol vitamin d2 ergocalciferol calcidiol and calcitriol they
all referring to the various forms of vitamin D in our body or in the food that we eat vitamin d3
is also known as cholecalciferol this is the form made naturally by the body in response to sunlight
vitamin d2 is also known as ergocalciferol and this comes from plants vitamin D supplements
come in the form of either vitamin d3 or vitamin d2 calcitriol or 125 dihydroxyvitamin D if you
prefer is the active form of vitamin D in our body let's say you're enjoying yourself a fine day at
the beach or just walking out and about on a fine sunny day that Sun is beaming down on that glowing
skin of yours that sunlight contains ultraviolet B or UVB radiation and when it hits your skin cells
it turns 7 D hydro cholesterol into vitamin d3 meaning cholecalciferol vitamin d3 in turn
binds to vitamin D binding protein and this is transported to the liver where it gets converted
to calcidiol aka 25 hydroxy vitamin D calcidiol is the storage form of vitamin D in the body
calcidiol is later converted to the active form of vitamin D in the body meaning calcitriol or
125 dihydroxy vitamin D this conversion of calcidiol into calcitriol or calcitriol mainly occurs
in the kidney but also takes place in different tissues and cells of the immune system such as
lymph nodes alveolar macrophages and not only in alveolar macrophages but in the alveoli themselves
so vitamin D can become activated in alveoli the same cell responsible for getting oxygen into the
blood and removing carbon dioxide from our blood yeah those cells the same cells that bacteria and
viruses like coronavirus and influenza invade in our lungs yeah those cells hmm so the vitamin D
becomes activated by our alveolar cells and immune cell in our lungs perhaps that has something to do
with our longest ability to fight off respiratory infections well yeah that's exactly the case but
this is a very big topic to cover so I'm gonna make this one my next video vitamin D in all of
its forms is a fat soluble vitamin it's one of only four fat soluble vitamins in our body along
with vitamins A E and K unlike non fat soluble vitamins fat soluble vitamins can be stored in
the liver this can be a good thing because it's nice to have that reserve when you're needed but
it can also be a bad thing because that means that dangerous levels can accumulate in the body
and because of that toxicity from fat soluble vitamins is much more common than for water
soluble vitamins however this usually only happens when you take mega doses of supplements over a
long time frame vitamin d3 is only found naturally in a few different food sources mainly fatty fish
like cod swordfish tuna and salmon and mackerel does anyone eat mackerel these days I don't know
but what about milk milk doesn't naturally contain vitamin d3 but it has been fortified
with it for almost a hundred years but other dairy products made from milk like cheese and ice cream
aren't typically fortified with vitamin D and contain only small amounts some yogurts juices
in breakfast cereals are fortified for older adults to meet the recommended daily allowance
of 800 IU or international units they would have to drink about 4 cups of fortified milk per day
vitamin d3 mainly comes from sunlight though not food but the skins production of vitamin D
depends on a number of factors only some of which you have control of humans first evolved near the
equator in Africa it's at the equator where the sun's rays directly hit the earth for most of
the year our ancestors there back in the day wore little to no clothing and that's why they never
had to worry about being vitamin D deficient not that they knew what vitamin D was back then but
anyway the more melanin in the skin the darker the skin and that protects the deeper layers of
the skin from UV damage over time as some groups of humans migrated away from the equator their
skin lightened to enable more efficient and D production because of less direct sunshine also
in the last 300 years or so people spent less time outdoors because of working in buildings
and in the last 100 years people spend more time traveling in cars which means less sunlight on
their skin and over the last 40 years or so more and more people rubbing sunscreen lotion on their
skin means less UVB absorption it rubs the lotion on its skin or else it gets the hose again and
don't get me wrong too much UVB light makes people more prone to getting skin cancer it's a known
risk factor for most of the 3 million-plus skin cancers that occur every year just in the United
States alone so rubbing the sunscreen lotion on the skin it's a good thing in general so depending
on the season where you live where you travel the time with a day the clothing you wear the umbrella
that you use all of these factors determine how much UVB light hits your skin the sun's rays are
both direct between 10 a.m. and 3 p.m. however the further you live from the equator the less
UVB radiation you receive people who live north of about 37 degree latitude can't make any vitamin D
from sunlight from November to March even if they spend all day outside Barenaked why is this the
case during the winter months the earth tilts away from the Sun ultimately leading to less sun rays
hitting the earth and you know what else having darker skin means less UVB absorption which means
less vitamin d3 production also as we age our body becomes less efficient at converting UVB
light into vitamin d3 and this is why older people as well as darker skin people are more prone to
having lower vitamin D levels to make matters worse many older people have reduced exposure
to sunlight for different reasons and may not beginning enough vitamin D in their diet vitamin
d3 which eventually is converted to the active form in the body calcitriol has a very important
role in the body many roles actually one of the most important is to signal the intestines to
absorb calcium into the bloodstream without enough vitamin d3 your body will start breaking down bone
to increase calcium levels in the blood and no one wants that this happens even if you have enough
calcium in your diet besides strengthening bones vitamin D helps reduce fractures in the elderly by
preventing muscle deterioration and reducing the chances of falling but what is vitamin D
deficiency the official definition of a vitamin deficiency means that specific health problems
arise as a direct result of not having enough of a specific nutrient true vitamin D deficiency
and children causes rickets a bone disease where the legs become bowed this is rare in the United
States though vitamin D deficiency in adults can lead to osteomalacia meaning softening of the
bone and osteoporosis leading to bone fractures so what if you don't have deficiency per say but you
have less than ideal levels of a specific vitamin well this can increase your risk of various health
issues even though they're not solely responsible for these problems this is what we call an
insufficiency most medical societies consider someone vitamin D insufficient if their level
is between 12 to 20 ng per ml or 30 to 50 nano moles per liter and vitamin D deficiency is
a level less than 12 ng per ml most experts consider normal levels being above 20 and less
than 50 ng per ml and most people in United States have values around 20 in the National
Health and Nutrition Examination Survey back in 2005 to 2006 42% of adult participants had levels
less than 20 the American Association of clinical endocrinologist says that values between 30 and 50
have potential health benefits beyond bone health but there are a lot of conflicting studies on this
and randomized control trials are being done right now to try and sort the cell based on my research
it seems like levels of around 30 ng per ml is the sweet spot but having to high levels can cause
other health issues in one study levels above 32 ng per ml resulted in people getting less
quality sleep probably because higher vitamin D levels suppress melatonin production from the
pineal gland in the brain the risk of vitamin D toxicity typically occurs in levels above
100 in adults who are also ingesting substantial amounts of calcium vitamin D toxicity whether it's
from vitamin d3 or vitamin d2 generally occurs after inappropriate use of vitamin D for example
when someone is taking mega doses of supplements vitamin D intoxication has been reported in adults
taking more than 60,000 IU's per day symptoms of toxicity are related to increased calcium levels
in the blood which can cause confusion nausea vomiting muscle weakness kidney stones headache
belly pain and heart arrhythmias it's especially important to avoid excess vitamin D in pregnancy
because that can cause calcium levels to rise to the point of causing seizures and the mother and
developmental problems in the baby some might wonder can I get toxic levels of vitamin D just
by lying in the Sun too long well if you don't ingest vitamin D in your diet or take a supplement
the answer is no because prolonged exposure to sunlight by itself doesn't cause toxic amounts
of vitamin d3 in the body that's because there are multiple studies showing that prolonged exposure
of the skin to sunlight results in a maximum level of 75 if possible it's best to get vitamin D from
food infra modest sun exposure and be sure to avoid getting sunburned so if you live north
of the 37th parallel which broadly divides the United States in half horizontally you can only
get enough sun exposure to make vitamin D during the summer months but if you live south of that
border you can most likely get enough vitamin D from the Sun alone pretty much year-round so
typically 10 minutes of Sun a few days out of the week to the arms into the legs without sunscreen
will provide enough vitamin d3 production for adequate levels the question of whether or not
the general population should have their vitamin D levels measured is up for debate on one hand
most healthy people who get some Sun and/or have enough vitamin D in their diet from fish or from
fortified foods such as milk well most of these people will have normal vitamin D levels but
for people who aren't getting enough Sun or not getting enough in their diet they probably should
have their levels checked but it's not always practical for people to get to the doctor and
get their levels checked especially during the Covid 19 pandemic so if you're not getting enough
vitamin D from the Sun and/or from the foods that you're eating taking a vitamin D supplement is a
good alternative for most people 800 or 1000 IU either every day or every other day will be
adequate me personally I take 1000 IU every day or every other day at least when it's not in the
summer I'll put a link to the one that I take in the description below some people ask which
supplement should I take vitamin d3 or vitamin d2 they're probably about the same in terms of
effectiveness but vitamin d3 might be slightly better regardless of which one you take if you
do take one it's generally advised to never take more than 4,000 IU's per day as this can result
in toxic levels over time but there are other factors to consider and this is why it's always
best to have a discussion with your doctor and just a few more things to remember people with
darker skin are more likely to have lower levels of vitamin D same for the elderly same for infants
same for people who live in countries that don't have food that is fortified with vitamin D same
for people who live in countries further away from the equator smokers tend to have lower
vitamin D levels as well and same goes for those who are obese and all these things that I just
mentioned happen to be the same risk factors for people having worse outcomes with covid 19 is this
just a coincidence is there a correlation and is there causation it's very interesting and there
are a bunch of studies about vitamin D that are related to Covid 19 that just came out in the last
few weeks and they're pretty mind-blowing and this is going to be the topic of my next video
Covid 19 and vitamin D does vitamin d3 prevent Covid 19 does it lesson the severity of covid 19 should
people take vitamin d3 for Covid 19 if so how much should they take so hit that subscribe button
and click on the bell notification that way you don't miss out on that one and I'll see you then