It looks like DrGreger changed his VitD recommendation from 4000IU/day to 2000IU/day (or 15-30min sun) yesterday:
<a href=http://www.facebook.com/NutritionFacts.org/posts/193068787424836>http://www.facebook....68787424836</a>
I think these are his studies changing his decision for 20-30ng/ML is safest and not 50-60 for Vitamin D:
"Vitamin D deficiency is common in healthy adults
and children as well as in the chronic kidney disease (CKD)
population. What was once a disease of malnourished children
in the developing world has re-emerged and reached
pandemic proportions. In parallel with this development,
there is a growing awareness that vitamin D is not simply a
‘calcaemic hormone’ but plays an important role in the
prevention of cardiovascular disease, infectious and autoimmune
conditions, renoprotection, glycaemic control and
prevention of some common cancers.
...
Although numerous studies have not
observed any adverse effects of higher
vitamin D status, a few have. Historically,
the main health risks associated with
excessive vitamin D are linked with
abnormal plasma calcium concentrations.
Excessive vitamin D is recognized to
cause hypercalcemia by increasing intestinal
calcium absorption or by increasing
mobilization of bone calcium. Although
hypercalcemia is uncommon with intakes
less than 10 000 IU/d,3 knowledge of
non-calcium-related adverse events is
limited. At least some evidence suggests
that high vitamin D status may be associated
with increased risk of some cancers.
In a large case control study of prostate
cancer in Finland and Norway, both
low (<7.6 ng/mL) and high (>32 ng/mL)
25(OH)D concentrations were reported
to be associated with an increased incidence
of prostate cancer (50% and 70%,
respectively) compared with individuals
with serum 25(OH)D concentrations
between 16 and 24 ng/mL.4 A direct relationship
between higher vitamin D status
and the development of esophageal
carcinoma also has been observed in
Chinese men.5 Interestingly, all the participants,
including those in the highest
quintile, were vitamin D deficient (<20
ng/mL 25(OH)D). In a study in Finnish
smokers, Stolzenberg-Solomon et al6 associated
higher baseline 25(OH)D (>26.2
ng/mL) with a 3-fold increased risk of
pancreatic cancer compared to individuals
with the lowest baseline status (<12.8
ng/mL). Overall, these studies suggest
there may be an optimum status and that
values below or above may increase risk
of certain types of cancer.
Adverse events associated with high vitamin
D status other than cancer also have
been observed. Recent data from large
epidemiologic studies, including the Third
National Health and Nutrition Examination
Survey (NHANES III) and the Framingham
Heart Study, suggest that a “U-shaped
curve” relationship exists with all-cause
mortality and the incidence of cardiovascular
disease because both low and high
25(OH)D concentrations elevated risk.7,8
In the NHANES III study, higher mortality
risk was observed in participants
with 25(OH)D above 49 ng/mL. In the
Framingham study, the lowest cardiovascular
disease risks were found in
participants with baseline 25(OH)D levels
of 20 to 25 ng/mL but increased with both
lower and higher values,8 thus suggesting
that increased cardiovascular risk occurred
at levels below 30 ng/mL. Furthermore,
the optimal 25(OH)D levels for protection
against cardiovascular disease and certain
types of cancer may differ from those
for bone metabolism or normal parathyroid
hormone physiology. It should also
be emphasized again that although few studies
have shown adverse effects of
higher vitamin D status, many do not.
Regardless, it remains prudent to be cautious
in case there are circumstances
where ill consequences will surface."
- from 'too much.pdf' <a href=http://is.gd/vT4Ogh>http://is.gd/vT4Ogh</a>
"A vitamin D intake
of 400 IU/day will only cause a modest increase in 25(OH)
D levels by 2.8–4.8 ng/ml. To raise 25(OH)D levels from
20 to 32 ng/ml requires an additional intake of 1700 IU/day
[56] ... Vitamin D intoxication is observed when 25(OH)D
serum levels are > 100 ng/ml [1]. This topic is discussed
in detail in subsequent sections." from 'how much too much.pdf' <a href=http://is.gd/vT4Ogh>http://is.gd/vT4Ogh</a>
And he may have seen more in 2011 as these are the 2010 studies he looked at.
"There are currently no guidelines for the treatment of
vitamin D deficiency in healthy adults. A vitamin D intake
of 400 IU/day will only cause a modest increase in 25(OH)
D levels by 2.8–4.8 ng/ml. To raise 25(OH)D levels from
20 to 32 ng/ml requires an additional intake of 1700 IU/day
[56]. Treatment regimens vary widely, ranging from
600,000 IU of D2 or D3 as a single dose every 3 months
(Stoss regimen), 2,000–4,000 IU daily for 3–6 months or
50,000 IU three times per week. All of these regimens have
been shown to increase circulating 25(OH)D levels, but
only the regimens using at least 600,000 IU ergocalciferol
were able to achieve adequate 25(OH)D levels [82]. The
total dose used and not the dosing frequency determined the
25(OH)D level achieved [82]. Only one study has looked at
long-term treatment with ergocalciferol, reporting that
50,000 IU every other week (median study period 2 years) is safe and prevents recurrent vitamin D deficiency [83]." - 'how much is too much.pdf'
--
I remember hearing some ills of Vitamin D this study on calcium supplements (I remember this study 2yrs ago in older people): 'What jumped out at us was that higher vitamin D intake had a statistically significant association with having a greater volume of brain lesions. But before you worry about taking “too much” vitamin D, taking ample amounts of the “sunshine-and-seafood” vitamin doesn’t appear to be the main cause of artery calcification, as the researchers noted. In fact, as Dr. Ames reported, prior studies show just the opposite: having higher vitamin D levels in your blood appears to reduce the risk of dementia (Przybelski RJ, Binkley NC 2007). What’s to blame for damage to brains? Vitamin D or excess calcium?It appears much more likely that the brain-damaged volunteers’ high calcium consumption was the problem, not their vitamin D intake, which was merely adequate.' http://newsletter.vi...4.cfm?x=b11,0,w
and also 'Cancer dud' <a href=http://www.longecity.org/forum/topic/41913-high-vitamin-d-a-cancer-dud/>http://www.longecity...cancer-dud/</a>
--
But this is the .png always linked in paleo community that looks to reach 50-60ng/mL vitamin D: <a href=http://is.gd/34nbhx>http://is.gd/34nbhx</a> <a href=http://is.gd/gk4zF0>http://is.gd/gk4zF0</a> I have read anecdotally that people who are obese (in comments section <a href=http://www.trackyourplaque.com/blog/2011/08/you-could-take-vitamin-d-or.html>http://www.trackyour...n-d-or.html</a>) may have to take more VitD (but the variation from person to person on how much to take to get adequate blood levels is different regardless of size as mentioned in the comments by DrWilliamDavis). Comment by someone:
"I just wanted to add my experience on Vit. D3 supplementation.
Two years ago in July I started supplementing 5,000 i.u. Vit. D3 a day. My sister had been found low, I live relatively the same lifestyle, and thought, “what the heck, I’ll start and get my blood tested in late winter next year”.
That next March I had a blood test and found my blood levels to be at a whopping 32 ng/ml. My doctor said “fine, you’re within range” and I thought, “no, that’s not fine” and started to take 15,000 i.u. a day. In March again this year I had a blood draw, and expected to see a very high ng/ml of Vit. D. My actual result? It had raised to 45 ng/ml. I was floored that with that amount, my levels had only raised such a small amount.
I will add that I am obese. I just wanted to give you my experience with D3 supplementation in case it helps someone else. I have now upped my supplementation once more to 20,000 i.u. a day, and if my next blood test is appreciably better, will hold at that level or drop back some. I will add that I haven’t had many if any colds this past year, so even if I have not attained a more optimal level (perhaps I can’t due to obesity) it’s still doing me a lot of good."
I have also read anecdotally from DrWilliamsDavis in the comments that amounts needed to maintain levels decrease as blood levels reach desired levels and testing every 6months is recommended and also says in the comments on trackyourplaque responding to 'too much.pdf':
"As knowledge marches forward, there will always be differing observations made, some good, some bad, some indifferent.
However, if we weigh the totality of evidence (and I throw in my experience that now amounts to several thousand patients), there has never been any strategy as powerful as vitamin D–except for elimination of wheat in the human diet, the two most spectacular new health strategies I have encountered in my career."
Edited by Rick Moranis, 31 August 2011 - 07:01 AM.
