True story:
"It is structurally similar to steroids such as testosterone, cholesterol, and cortisol (though vitamin D3 itself is a secosteroid)."
Cholecalciferol - Wikipedia, the free encyclopedia
Well it does not fit term vitamin as it can be synthesized from sun, but it acts as both. It is active part of hormonal pathways and low vitamin d does negatively influence hormonal balance, supplementing with it when levels are low helps great deal, hovewer when levels are not low supplementing with it does not really do much. Both low and too high levels are connected to higher mortality rate (and faster aging by some claims).
Sometimes in some hormonal dysfunctions body starts "stealing" vitamin d- to fill some pathways- I think that si part of what some guys dubbed as "pregnenolone steal".
As for bodybuilders and people who exercise heavily, and eat a lot of protein- all of us- kidneys are working overtime, and probably all of us have raised creatinine levels. Now; combining too much vitamin d and struggling kidneys- it does not sound good to me.
Toxicity is not an issue unless taken in really big numbers altough there is not too much data on this, but mind you even if there is problem with toxicity it will take a while to manifest itself- for example alcohol toxicity- even "street alcoholic" survive many, many years before it catches them up.
It takes quite a short exposures on sun to top up vit d levels to max (with sun exposure ther is no possible sides as body has mechanisms to protect itself unlike from oral supplements).
So if someones vit d levels are on lower end usualy he either has some underlying health issues (vit d steal?) or poor absorbtion or he lives in North Pole or poor lifestyle.
At some point people were over obsessed vit vitamin c, and every runner was eating vit c tablets like gummy bears, than it was something else... Now is vitamin d...
Anyway, over 5 centuries ago famous alchemist Philippus Aureolus Theophrastus Bombastus von Hohenheim (better known as Paracelsus) said:
"All things are poison, and nothing is without poison; only the dose permits something not to be poisonous." or more simply: The dose makes the poison
Last edited by Jelisej; 02-18-2013 at 10:12 AM.
Hmm, interesting points. But I think many are too quick to say "untested, unproven, possibly dangerous" about vitamin D. There are really, really rare instances where the kidneys cannot convert D into the active form, but the person would definitely know about this. actually i had a client see me who had this condition, and she was unable to benefit even from sunlight or indoor tanning as the kidneys would not convert it. but she was very ill, and this would very likely be an absolute minority of people. the kidneys do not have trouble converting a substance that has been in our physiology for thousands of years, and to suggest they do without proof is kinda silly. we are talking microgram amounts of D3.
Plenty of studies have shown a reduction in all-cause mortality when vitamin D is "high" (in reality normal).
also, when you mention the 'vitamin D steal' i'm not sure what you mean. is it that enough D3 is not left for all its required functions, or is it that the substrate it is made from is depleted (as is the case in the cortisol progesterone steal)?
Claims of Vitamin D3 toxicity are greatly overblown, in my opinion.
Benefit-risk assessment of vitamin D suppleme... [Osteoporos Int. 2010] - PubMed - NCBI
Vitamin D tells us about the follow thru of the steroid pathways. if its low at the end it tells you there is a proximal problem in the system too.
-Pregnenlone steal from thyroid disease is number one
-Any type of stress, emotional, physiological, metabolic, psychological, mental, etc...
-inflammation from any source.
As for vitamin d steal:
If I rember correctly; I may be wrong tough that body sometimes use VitD+ T3 to boost preg/adrenals among others, I've researched this long time ago
Kidneys- I was talking about possibility of hardening of kidneys, and kidney stones- some irregularities have been noticed in both blood in urine like increased calcium (hypercalciuria and hypercalcemia).
You may well be right and these thinga mean nothing, its just that I'm bit always on sceptical side you're opposite. its good for other readers to hear both sides and then decide.
Last edited by Jelisej; 02-21-2013 at 02:09 PM.
I don't think this is the case because, unlike steroid hormones which only require cholesterol for synthesis, vitamin D also requires UV light. there can be plenty of conversions and follow throughs happening, but if there is not sufficient UV light or food intake, there is not going to be sufficient vitamin D. period. This does not indicate any metabolic or hormonal problems.
my question is: why not assume that the blood levels created by summer sun are fairly indicative of an "optimal" amount and keep levels up there year-round? for example, in the link you cite, they say 75-110 nmol/l. but John Cannell of the vitamin d council has 125 nmol/L listed as the lower end of the range. this is the lowest level one would expect with regular sun exposure. again, my question: if such levels are potentially dangerous, as the study suggests, why does our body make them in response to sun?
In research, change is slow-moving and there is a tendency to apply a type of precautionary principle to vitamin D, as evidenced by this article, that is appropriate to drugs but not to orthomolecules. if vitamin D levels in the physiological range are harmful, show me the evidence. Other than vague statements like "might be dangerous" in the paper you linked to, there is none, because it does not exist.
further evidence that the RDI is too low occurs when the authors of the paper say that to achieve 75-110 nmol/L most adults will need 1800-4000 units. If you accept the idea that summer sun and the skin produce a physiologically normal level of vitamin D, then we can safely assume that most adults will need more than 4000 units.
Attached are both my blood tests, 2 weeks on vitamin D and then 11 weeks on.
2 weeks on supplement @ 5000IU per day
11 weeks on supplement @ 5000IU per day
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Good feedback, O.N. Thanks for sharing.
Living in a rainy, low-sun environment, I probably should get bloods done for deficiency.
All advice given is for entertainment value only. And it's free. Take it for what it's worth.
^^ no need to get bloods as without supplements by this time of year you almost certainly are deficient (i mean no harm in doing so but why waste the time and money if it costs you anything).
supplement with 5000 IU for a month then get tested. sometimes I like to use a few initial doses of 20-50,000 to get the levels up faster