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What's the Perfect Vitamin D Dose? — Transcript

by Dr Brad Stanfield · 2,775 words · 432 segments · language en · Watch on YouTube

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0:00mega dosing vitamin D has skyrocketed in
0:02popularity over the past 3 to 4 years
0:05particularly when it's paired with
0:06vitamin K2 and magnesium but the
0:08uncomfortable reality is that there's a
0:11distinct lack of evidence of benefit
0:13from the clinical studies we have to
0:14date not only that there are several
0:16worrying side effects from Mega doing
0:18vitamin D and there's an important
0:20overall learning point we can get from
0:22the sorry Saga so what is vitamin D
0:25vitamin D is a fat soluble vitamin
0:27that's naturally present in a few food
0:30and added to others it's also produced
0:32when ultraviolet rays from sunlight
0:34strike the skin and Trigger vitamin D
0:36synthesis but the vitamin D from sun
0:38exposure foods and supplement is
0:41biologically inactive and it must
0:43undergo two transformations in the body
0:45to activate it the active form is called
0:49calcitriol vitamin D promotes calcium
0:51absorption in the gut and maintains
0:53adequate blood levels of calcium and
0:55phosphate to enable normal bone
0:57mineralization but it's also needed for
0:59bone growth and remodeling without
1:02sufficient vitamin D bones can become
1:04thin and brittle this can lead to
1:06rickets in children and weakening of the
1:08bones in adults but it's not just bones
1:11that vitamin D is essential for vitamin
1:13D receptors are found all throughout the
1:15body and has a critical role to play in
1:17the reduction of inflammation as well as
1:20modulation of other processes such as
1:22cell growth neuromuscular and immune
1:24function as well as glucose metabolism
1:27the role that vitamin D plays in immune
1:29function is one of the main reasons why
1:31its popularity has skyrocketed in recent
1:33years and we'll cover that later in the
1:35video the trouble is many of us have low
1:38levels of vitamin D there are only a few
1:41foods that naturally contain vitamin D
1:43such as fatty fish and other animal
1:45products instead the primary source of
1:48vitamin D for humans is our skin when UV
1:51radiation specifically type B at a
1:54wavelength of approximately 290 to 300
1:57NM hits our skin it enables the
2:00production of vitamin D but UVB
2:02radiation doesn't typically penetrate
2:04glass so since most of us are working
2:06indoors we often don't see enough
2:09sunlight and nor should we UV exposure
2:12is one of the most preventable causes of
2:13skin cancer and skin aging but because
2:16of these problems with getting enough
2:18vitamin D it's estimated that between
2:2092% of men and 97% of women have low
2:24levels of vitamin D in severe cases this
2:28deficiency causes weakening of bones
2:30muscle spasms and dental
2:32abnormalities and there are certain
2:34groups of people who are at greater risk
2:36of vitamin D deficiency compared to
2:38others for example older adults are at
2:40increased risk of developing vitamin D
2:43insufficiency partly because the Skin's
2:45ability to produce vitamin D declines
2:47with age also older adults tend to spend
2:50more time indoors compared to younger
2:52people other people such as myself who
2:55always wear sunscreen are also at risk
2:57of low vitamin D levels as our people
3:00who struggle to absorb particular fats
3:02for example if you've got celiac disease
3:04Crohn's disease or ulcerative colitis
3:07these diseases cause problems finally
3:09people with obesity often have low
3:11levels of vitamin D because the vitamin
3:13D is stored in the fat cells but all of
3:16this brings up an important question
3:18since most of us are likely deficient in
3:20vitamin D why don't we all have symptoms
3:23of vitamin D
3:24deficiency well like I mentioned earlier
3:27some animal products do contain vitamin
3:29D and since the 1930s vitamin D has been
3:32fortified in foods such as milk
3:34breakfast cereals and margarine but we
3:37don't just want the minimum amount of
3:39vitamin D to not get symptoms we want
3:41the best so what is the optimal blood
3:43level for vitamin D well typically in a
3:46blood test it's the inactive form of
3:48vitamin D that's measured because it's
3:50got a very long halflife and is quite
3:52stable that's compared to the active
3:54form of vitamin D which is generally not
3:56a good indicator of vitamin D status
3:59because it's got a short halflife
4:01measured in hours and the blood levels
4:03are tightly regulated meaning that the
4:05active form of vitamin D does not
4:07typically decrease until the vitamin D
4:09deficiency is severe for the optimum
4:11blood level the food and nutrition board
4:14recommend a level above 50 nanom per
4:16liter but that's in contrast to the
4:18endocrine society which suggest a higher
4:21level of 75 nanomoles per liter which
4:24they say is necessary to maximize the
4:26effect of vitamin D on calcium bone and
4:29muscle metabol ISM so how should we
4:31reach this perfect level well in terms
4:33of vitamin D recommendations even though
4:35sunlight is a major source of vitamin D
4:37for some people the food and nutrition
4:39board based their vitamin D
4:41recommendations on the assumption that
4:43people receive minimal sun exposure so
4:45for older adults over 70 years old they
4:48suggest 800 international units which is
4:51also in contrast to the endocrine
4:53society which states that to maintain a
4:55level of above 75 nanom per liter in the
4:58blood adults need to consume at least
5:001,500 to 2,000 international units per
5:04day of supplemental vitamin D which
5:07leads us to the next question which type
5:09of vitamin D supplement is best because
5:11there are two primary forms we've got
5:14vitamin D2 and vitamin D3 most evidence
5:17however indicates that vitamin D3
5:20increases our blood vitamin D levels to
5:22a greater extent compared to vitamin D2
5:25personally I supplement between 1,000 to
5:282,000 intern units of vitamin D3 from
5:31microv vitamin but remember that just
5:33because I take a supplement does not in
5:35any way mean that you should as well
5:38we're going to discuss Mega doing
5:40vitamin D shortly but first should we do
5:42a vitamin D blood test after all we want
5:45the best levels vitamin D blood tests
5:48have become a more common part in
5:49routine blood work ordered by primary
5:52care physicians irrespective of the
5:54indications for this practice however
5:56the US preventative Services Task Force
5:59found in sufficient evidence to assess
6:00the benefits and harms of screening for
6:03vitamin D deficiency in asymptomatic
6:05adults it added that no Professional
6:07Organization recommends population
6:09screening for vitamin D deficiency the
6:12reason for this is that if a person is
6:14supplementing with 1,000 to 2,000
6:16international units of vitamin D their
6:19levels are likely perfect so in New
6:21Zealand where I practice medicine the
6:23healthare system won't pay the $60 for
6:25the Vitamin D blood test because there's
6:27no evidence that supplementing with more
6:29than that is beneficial and will come to
6:31that shortly now that's quite different
6:33to the USA Healthcare System where
6:35there's a trend to measure everything
6:37now of course it's your health your
6:39decision if you want to pay for a blood
6:41test for vitamin D go for it but equally
6:44I've never done it myself and nor do I
6:46think that there's any benefits based on
6:48the research that we're about to go
6:49through on that point what evidence do
6:52we have of vitamin D's benefits the food
6:55and nutrition board found that the
6:56evidence was inadequate or too
6:58contradictory to conclud that vitamin D
7:00had any effect on a long list of
7:02potential Health outcomes except for the
7:04measures related to bone health there
7:07are eight health conditions that have
7:08been well studied in regards to vitamin
7:10D and we'll go through each one then
7:12we'll finish by looking at the overall
7:14important learning point starting with
7:17bone health and osteoporosis bone is
7:20constantly being remodeled however as
7:22people age particularly women during
7:24menopause bone breakdown rates overtake
7:26the rates of bone building and over time
7:29bone density can decline however the
7:32evidence of the impact of vitamin D is
7:34inconsistent in a metaanalysis of
7:36randomized control trials involving over
7:3950,000 individuals there was no evidence
7:41that vitamin D prevented fractures
7:44further analysis concluded with moderate
7:46certainty that vitamin D supplementation
7:48does not reduce the numbers of Falls or
7:51injuries similar findings were found in
7:532022 from the vital trial once again
7:56vitamin D supplementation did not reduce
7:59the risk of fractures which led to the
8:01conclusion that following the guidelines
8:03and taking 1,000 to 2,000 international
8:06units of vitamin D is a good idea for
8:08bone strength but Mega doing has no
8:10additional benefits the second proposed
8:13health benefit is muscle function
8:15unfortunately multiple randomized
8:17control trials have shown no effect on
8:19muscle performance this is despite the
8:21trials increasing the blood naad to more
8:24than 80 nanomoles per liter in those
8:26studies vitamin D supplementation did
8:29not affect lower extremity power
8:31strength or lean mass the third proposed
8:34benefit is cancer laboratory and animal
8:37studies suggest that vitamin D May
8:39inhibit cancer growth and slow tumor
8:41progression for example by promoting
8:43cell differentiation and inhibiting
8:46metastases vitamin D may also have
8:48anti-inflammatory effects and if you
8:51look at the observational studies where
8:52you observing the population you do see
8:55this trend those studies show that low
8:57blood levels of vitamin D seem seems to
8:59be associated with increased risks of
9:02cancer these types of studies are often
9:04what health influencers will promote as
9:06justification for Mega doing vitamin D
9:09but in the largest randomized clinical
9:11trial the vital trial which investigated
9:13vitamin D and cancer there was no
9:16difference between the vitamin D groups
9:18and Placebo groups and worryingly in a
9:21separate metaanalysis of 10 randomized
9:23control trials it found an increased
9:25rate of pancreatic cancer if the blood
9:27vitamin D levels were above 100 nanom
9:30per liter all of these lines of evidence
9:32led to the conclusion that Vitamin D
9:34supplements do not prevent cancer yes we
9:37might be tricked into thinking that it
9:38does if we just looked at the
9:40observational research but from the
9:42randomized clinical trials there's no
9:44effect number four of eight is
9:46cardiovascular disease vitamin D helps
9:49to regulate the renin Angiotensin
9:52aldosterone system vascular cell growth
9:54and inflammatory Pathways vitamin D
9:57deficiency is associated with ular
9:59dysfunction arterial stiffening left
10:02ventricular hypertrophy and high
10:04cholesterol levels for these reasons
10:06vitamin D has been linked to heart
10:08health and the risk of cardiovascular
10:10disease and just like the cancer section
10:13that we went through if we look at the
10:15observational research we can see a link
10:17between low levels of vitamin D and
10:19cardiovascular disease these studies
10:22suggest that the risk of heart disease
10:24is 10% lower for each 25 nanom per liter
10:27increase in blood vitamin D levels
10:30again this is the type of data that
10:31health influencers will misleadingly
10:34post because in contrast to the
10:36observational studies clinical trials
10:38provided little support for this
10:40hypothesis for example a three-year
10:43trial in New Zealand randomized over
10:455,000 adults to vitamin D or a placebo
10:48unfortunately vitamin D had no effect
10:51for cardiovascular disease those
10:53findings were backed up from the vital
10:55study which also found no effect from
10:57Vitamin D supplements with ECT to heart
11:00attacks Strokes or deaths from
11:02cardiovascular disease crucially these
11:04effects did not vary by the Baseline
11:06levels of vitamin D in the blood overall
11:09the clinical trials show that Vitamin D
11:11supplements do not reduce the risk of
11:13cardiovascular disease even for people
11:16with low blood vitamin D levels number
11:19five depression vitamin D is involved in
11:22various brain processes and vitamin D
11:24receptors are present on neurons in
11:26areas of the brain thought to be
11:28involved in depression
11:29again we can get tricked by the
11:31observational research so when we
11:33observe the population we do see that
11:35yes people with low levels of blood
11:37vitamin D seem to have higher rates of
11:40depression the clinical trials however
11:42do not support these findings for
11:45example a metaanalysis of nine trials
11:47involving just under 5,000 participants
11:50found no effects in the symptoms of
11:52depression with Vitamin D supplements
11:54compared to a placebo you see the theme
11:57don't you good levels of vitamin D are
11:59are a marker of good health but they
12:01don't seem to be the cause of good
12:02health if we think about this a
12:04different way all world champion drivers
12:06wear helmets but if you or I put a
12:09helmet on we're not going to magically
12:10change into a world champion driver it's
12:13the same for vitamin D if people have
12:15good levels of vitamin D in their blood
12:17they're likely practicing other healthy
12:19habits such as going out for a walk
12:21looking after themselves having a good
12:23diet and yes the occasional supplement
12:26number six of eight is multiple
12:28sclerosis or Ms Ms is an autoimmune
12:31disease of the central nervous system
12:33that damages the nerve cells
12:35interestingly the geographical
12:37distribution of Ms around the world is
12:40unequal people who live near the equator
12:42have a lower chance of developing Ms
12:44compared to if you're further north or
12:46south and while there's still work to be
12:48done the clinical trials so far where
12:50they test this idea have been
12:52disappointing overall vitamin D
12:55supplementation when compared to a
12:56placebo had no effect on relevant
12:58clinical outcomes such as recurrent
13:00relapse or worsened disability number
13:03seven is type 2 diabetes vitamin D plays
13:06a critical role in glucose metabolism it
13:09stimulates insulin secretion via vitamin
13:11D receptors on pancreatic beta cells and
13:14reduces peripheral insulin resistance
13:16through vitamin D receptors in the
13:18muscles and liver just like all the
13:20other examples observational research
13:23suggests a link between low vitamin D
13:25levels and type 2 diabetes rates but in
13:28a met anal is that combined 35
13:30randomized control trials involving over
13:3340,000 individuals vitamin D had no
13:36effect on insulin resistance or
13:39hba1c in the largest trial to date of
13:41Vitamin D supplements for diabetes
13:43prevention which randomized
13:462,423 men and women unfortunately
13:49vitamin D did not prevent the
13:50development of diabetes compared to a
13:52placebo but that study did find
13:55something interesting further analysis
13:57of that study showed a 62% lower rate of
14:00diabetes among participants who had low
14:03levels of vitamin D and who took Vitamin
14:05D supplements once again supplementing
14:08with 1,000 to 2,000 international units
14:10of vitamin D is probably a good idea but
14:13more than that there's no benefit the
14:16final area of interest is immune
14:18response because vitamin D receptors are
14:21found on immune cells it's thought that
14:23there's the potential to improve immune
14:26responses and yes there is some evidence
14:28for the idea a 2017 systematic review
14:31and metaanalysis of Vitamin D
14:33supplements found that supplementing
14:35with vitamin D at the recommended doses
14:37resulted in a 12% lower risk of
14:40developing upper respiratory tract
14:41infections compared to a placebo a
14:44subsequent metanalysis found the same
14:46thing so while it's a good idea to
14:48supplement in line with the endocrine
14:50Society recommendations there's no
14:52evidence of further benefit from Mega
14:54does I also want to speak on the idea of
14:57pairing vitamin D with vitamin K2 and
14:59magnesium this is exactly what I do as
15:02part of microv vitamin to help reach my
15:04recommended daily intakes of these
15:06micronutrients but currently there's no
15:08evidence that Mega doing any of these
15:10vitamins or minerals offers further
15:12benefits Beyond reaching the recommended
15:14daily intakes instead we do have
15:17evidence of harm from Mega doing vitamin
15:19D because vitamin D increases calcium
15:22absorption in the gut vitamin D toxicity
15:25results in marked high levels of calcium
15:28in the blood this causes nausea vomiting
15:31muscle weakness pain loss of appetite
15:34dehydration excessive thirst and kidney
15:36stones in extreme cases vitamin D
15:39toxicity causes renal failure
15:41calcification of soft tissues throughout
15:43the body cardiac arrhythmias and even
15:46death the overall lesson from going
15:48through the vitamin D research is to be
15:50incredibly skeptical about anyone
15:53promoting high levels of vitamin D they
15:55will often extrapolate findings from
15:57observational studies as justification
16:00to Mega do vitamin D that is incorrect
16:02we need to look at the randomized
16:04control trials instead of getting
16:06distracted by Mega doing vitamins or
16:08minerals we need to focus on the
16:10fundamentals of Health diet exercise and
16:13sleep and yes certain supplements can be
16:15used to help us reach the recommended
16:17daily intakes of various micronutrients
16:19so I use microv vitamin to do this and I
16:22designed microvi to make sure that I
16:24don't Mega do but again just because I
16:27take a supplement does not in any way
16:29mean that you should as well and make
16:30sure to check out this next video here
16:32on all of the strategies that you can
16:34use to optimize your sleep and thank you
16:36to the patrons supporting the channel

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