A little more about Beta Carotene and Vit A, written by Sally Fallon and Mary Enig, PHd

Under optimal conditions, humans can indeed convert carotenes to vitamin A. This occurs in the upper intestinal tract by the action of bile salts and fat-splitting enzymes. Of the entire family of carotenes, beta-carotene is most easily converted to vitamin A. Early studies indicated an equivalency of 4:1 of beta-carotene to retinol. In other words, four units of beta-carotene were needed to produce one unit of vitamin A. This ratio was later revised to 6:1 and recent research suggests an even higher ratio.5 This means that you have to eat an awful lot of vegetables and fruits to obtain even the daily minimal requirements of vitamin A, assuming optimal conversion.

But the transformation of carotene to retinol is rarely optimal. Diabetics and those with poor thyroid function, a group that could well include at least half the adult US population, cannot make the conversion. Children make the conversion very poorly and infants not at all - they must obtain their precious stores of vitamin A from animal fats6- yet the low-fat diet is often recommended for children. Strenuous physical exercise, excessive consumption of alcohol, excessive consumption of iron (especially from "fortified" white flour and breakfast cereal), use of a number of popular drugs, excessive consumption of polyunsaturated fatty acids, zinc deficiency and even cold weather can hinder the conversion of carotenes to vitamin A,7 as does the lowfat diet.

Carotenes are converted by the action of bile salts, and very little bile reaches the intestine when a meal is low in fat. The epicure who puts butter on his vegetables and adds cream to his vegetable soup is wiser than he knows. Butterfat stimulates the secretion of bile needed to convert carotenes from vegetables into vitamin A, and at the same time supplies very easily absorbed true vitamin A. Polyunsaturated oils also stimulate the secretion of bile salts but can cause rapid destruction of carotene unless antioxidants are present.

It is very unwise, therefore, to depend on plant sources for vitamin A. This vital nutrient is needed for the growth and repair of body tissues; it helps protect mucous membranes of the mouth, nose, throat and lungs; it prompts the secretion of gastric juices necessary for proper digestion of protein; it helps to build strong bones and teeth and rich blood; it is essential for good eyesight; it aids in the production of RNA; and contributes to the health of the immune system. Vitamin-A deficiency in pregnant mothers results in offspring with eye defects, displaced kidneys, harelip, cleft palate and abnormalities of the heart and larger blood vessels. Vitamin A stores are rapidly depleted during exercise, fever and periods of stress. Even people who can efficiently convert carotenes to vitamin A cannot quickly and adequately replenish vitamin A stores from plant foods.

http://www.berkeleywellness.com/htm...atured0103.html

A quote from that website:

"Supplements are tricky, however, because overdoses of D can be toxic, leading to kidney stones, kidney failure, muscle and bone weakness, and other problems. Danger starts at 2,000 IU a day. It’s nearly impossible to get too much D from food. A daily multivitamin with 400 IU of vitamin D is usually the best solution for those over 60. Some calcium supplements also contain D."

Weston A Price Discovered that natural Vit D produced from the skin and in animal and plant sources is present with up to 15 different isomers and other compounds that eliminate the toxicity. So yes pure cholecalciferol has shown toxicity but natural sources have not.

Natural sourced the quantities of vitamin D that are in food are tiny compared to what people on this board are taking




I don't see how Weston Price proved anything about the safety of taking thousands of natural form vitamin D IU in pills without doing trials, I will need to see that evidence before revising my opinion.

You seem to be saying ill effects are entirely due to the synthetic form - assuming that for the natural forms quantity is irrelevant. What kind of is nonsense is this? Eat Polar bear liver and natural source Vitamin A will make your skin fall off. It's the tiny amounts available in natural food sources that make natural sources safe. When taking 100 times the amount in pills you are going to get old and fat fast.

I have linked to studies that lead one to believe the effects of extra D are similar to that of aging.

[QUOTE=Lere]

That is mostly incoherent. I will try to respond.

Pills often isolate the vitamin or mineral. When you take D3 in a pill the other natural substances it is present with in nature are not with it regardless of the source of the D3 used in the pill. I would hardly call the 2800 iu of D in pork lard tiny either. 3 1/2 oz is not a lot of food.

I have idea what you mean about the age thing.

ref: http://forum.lowcarber.org/showthre...t=398243&page=3

Sources

Fish liver oils, fatty saltwater fish, dairy products, and eggs all contain vitamin D. It is found in butter, cod liver oil, dandelion greens, egg yolks, halibut, liver, milk, oatmeal, salmon, sardines, sweet potatoes, tuna, and vegetable oils. Vitamin D is also formed by the body in response to the action of sunlight on the skin. Herbs that contain vitamin D include alfalfa, horsetail, nettle, and parsley.

Comments
Intestinal disorders and liver and gallbladder malfunctions interfere with the absorption of vitamin D. Some cholesterol-lowering drugs, antacids, mineral oil, and steroid hormones (cortisone) also interfere with absorption. Thiazide diuretics such as chlorothiazide (Diuril) and hydrochlorothiazide (Esidrix, HydroDIURIL, Oretic) disturb the body's calcium/vitamin D ratio.

Cautions

Do not take vitamin D without calcium. Toxicity may result from taking amounts over 65,000 international units over a period of years.

Diet never has been the major source of vitamin D3 for most people. Ideally the human body uses 3000~5000iu/daily D3. Anyone who thinks you can get more than 10% of you daily Vit d requirement from food cannot do basic maths.

Evidence from clinical trials shows, with a wide margin of confidence, that a prolonged intake of 10,000 IU/d of vitamin D(3) poses no risk of adverse effects for adults, even if this is added to a rather high physiologic background level of vitamin D.

Cautions

Do not take vitamin D without calcium. Toxicity may result from taking amounts over 65,000 international units over a period of years.[/QUOTE]
I presume that mean 65000iu/d for a period of years.
Most people require only 5000iu/daily to attain and maintain the level 55ng 137.5nmol/l associated with least chronic disease incidence.
Calcium Foodsources. but be aware that the body uses calcium from food sources far better than supplemental calcium. I find it hard to understand what people are eating who fail to get sufficient calcium in their diet. I suppose if you can't eat dairy and won't eat greens there could be reasons to use calcium supplements but we make our own yoghurt, always have spinach in the garden, love cheese and nuts and eat plenty of sardines and other fish so I feel this is all a bit paranoid.
Sure there are some people who have been taking 50,000iu/daily for some time but most people will be fine with just 5000iu/d but some will require a bit less and others a bit more but regular 25(OH)D testing will soon sort out that issue.

Legon said ( he was talking about antioxidants),



By and large I think supplements are a mistake,
Avoiding sweets may spell a longer life


Vitamin Supplements Block Beneficial Effects of Excercise

Again, that's what they thought about antioxidants - until the excess mortality showed up.

I would like to see who funded that research.

But the reason they propose exercise helps diabetes is by causing a temp increase in free radicals, which then causes a immune response. This helps the body process carbs more efficiently and tehreby decreases the risk from diabetes.

One obvious problem I see is that from reading the linked article they simply measured a risk factor that they have a previous correlation to and did not study actual incidence of the proposed bad effects.

That's why I wondered whether other people share your view of yourself as exceptionally healthy (due to pill popping).

I think there is an assumption that you can shove 5,000 ius' of vitamin d3 into an unhealthy body and it all gets absorbed. I think there is also an assumption that a healthy person cannot get enough vitamin d from sun exposure and a proper diet.

I think somewhere between these assumptions lies the fallacies, misconceptions, deceptions or whatever you want to label it...

Just getting a vitamin d level up to a reference point does not in and of itself produce health. With that being said; it just doesn't make sense to put more emphasis on one vitamin being needed over another, etc... etc... etc... and also not emphasize other healthy things to do to achieve health, sleep, rest, exercise, fluid consumption, etc... etc... etc...

I love my herbs, but what I love more is the fact I don't try to shove them down other people's throats like I see vitamin d being done.....

The only pills I am currently taking are K2 and zinc. I use cod liver oil for D and A and I plan on making liver a regular meal also for D and A. Do I consider myself exceptionally healthy? Not really I just started doing this stuff in the last month. However the modern diet and the modern society make it difficult to get all of everything we need. The only options are to go out of our way to eat correct foods or to supplement. We aren't eating a natural diet, we aren't raising animals in natural environments and we are not eating wild plants, our bodies haven't adapted to that. Identifying which vitamins and minerals may be difficult to get in diet and lifestyle and adjusting accordingly is the only option unless you don't care about that aspect of health.

How many years have you been following the vitamin D story?

I've been following it for long enough to understand how Vitamin d affects telomeres and how this impacts on longevity

Have you any evidence that this is not the case?

No We know the most people if they lay naked in the midday sun FOR 20~30 minutes CAN get sufficient D3 but it is not realistic to expect that MOST people are in a situation where this is a practical possibility

Now can you list the dietary vitamin sources that provide 3000~5000iu/daily? ur bodies ideally use If you cannot provide a list of dietary sources that total around 4000iu/d then it it is a fact that diet isn't a practical source of vitamin D3.
How about facing up to the facts of life and call it the truth.
Indeed it is only one of many factors. I make no secret of the fact that omega 3<>omega 6 ratio is fundamental to inflammatory status as is magnesium status. But you have to understand that Vitamin D is pleiotropic that means it has effects on every cell in your body so if you get your vitamin D status wrong there isn't any cell in your body that can function as it evolved.

that is your opinion and not one that is supported by any scientific research or logical argument. There is very good evidence that globally vitamin d status is getting lower in all populations. We don't know the reasons, it could be pollution, it could be diet, it could be lifestyle but the lower 25(OH)D status gets the more vulnerable we are to all infections, pathogens and chronic diseases. celiac has changed from the 1950s from like 1:3000 to now 1:100. That is insane statistics. For the next 1-2 generations will it be 1:20... 1:5??
Much the same is true for Obesity Rates in the US and diabetes incidence
Low vitamin d is at the root of this increase in disease incidence.
No one forces you to read posts that don't interest you. When you come up with some recent science to support your opinion that maybe it will be worth consideration but at the moment you are simply burying your head in the sand because maybe you aren't mature enough to face up to the real facts of life.

For goodness sake all I am suggesting is the natural vitamin D status that allows human breast milk to flow replete with D3 and which is associated with the lowest incidence of chronic illness should be an aim for every reader here.

Now are you really saying that you would prefer people to attain and maintain a vitamin D status that allows cancer, heart disease, diabetes, and ms to flourish unimpeded?

or do you agree with me that the safest level to try to maintain is the one that has been associated with lowest incidence of disease incidence at at which we know the optimum amount of vitamin d is present in human breast milk?