I am raising my recommendation of 1,000 IU of vitamin D per day to 2,000 IU per day. Since 2005, when I raised it from 400 to 1,000 IU, clinical evidence has been accumulating to suggest that a higher dose is more appropriate to help maintain optimum health.
We have known for many years that we need vitamin D to facilitate calcium absorption and promote bone mineralization. But newer research has shown that we also need it for protection against a number of serious diseases. In recent years, scientists have discovered that it may help to prevent several cancers, cardiovascular disease, autoimmune disorders, psoriasis, diabetes, psychosis, and respiratory infections including colds and flu.
To focus particularly on cancer prevention, two recent meta-analyses (in which data from multiple studies is combined) conducted by the Moores Cancer Center at the University of California at San Diego and colleagues suggested that raising blood levels of vitamin D could prevent one-half of the cases of breast cancer and two-thirds of the cases of colorectal cancer in the U.S. Discussing the breast cancer analysis, study author Cedric Garland, Dr.P.H., stated that "The serum level associated with a 50 percent reduction in risk could be maintained by taking 2,000 international units of vitamin D3 daily plus, when the weather permits, spending 10 to 15 minutes a day in the sun."
A 50 percent reduction in breast cancer deaths would have saved the lives of more than 20,000 American women in 2009.
As these meta-analyses suggest, vitamin D deficiency is widespread. Aside from breast cancer, it is quite likely that hundreds of thousands of cancers of various kinds worldwide might be prevented each year if we all were getting enough.
We can get vitamin D through foods such as fortified milk and cereals as well as eggs, salmon, tuna and mackerel, but the amounts are not nearly sufficient to lift blood concentrations to optimal levels. Sun exposure is the best way to get it; ultraviolet rays trigger vitamin D synthesis in the skin. Factors that decrease the body's ability to make vitamin D include dark skin, heredity, obesity and certain medications, including some anti-seizure drugs (check with your pharmacist). Most significantly, sunscreen blocks vitamin D synthesis in the skin, and in northern latitudes (above that of Atlanta, Georgia) the sun is at too low an angle for half the year to provide sufficient UV radiation.
Low levels of vitamin D in the population as a whole suggest that most people need to take a vitamin D supplement. This may be especially true for seniors, as the ability to synthesize vitamin D in the skin declines with age. Always take your vitamin D with a fat-containing meal to ensure absorption.
Don't be concerned that 2,000 IU will give you too much. With exposure to sunlight in the summer, the body can generate between 10,000 IU and 20,000 IU of vitamin D per hour with no ill effects. In addition, no adverse effects have been seen with supplemental vitamin D intakes up to 10,000 IU daily.
If you decide to have your vitamin D levels tested, look for results in the normal range, from 30.0 to 74.0 nanograms of 25-hydroxy vitamin D per milliliter (ng/mL) of blood. If you are found to be deficient, your physician can advise you on the best way to raise your blood concentration into the normal range.
Andrew Weil, M.D., is the founder and director of the Arizona Center for Integrative Medicine and the editorial director of www.DrWeil.com. Become a fan on Facebook, follow Dr. Weil on Twitter, and check out Dr. Weil's Daily Health Tips blog.
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Dr. Richard Palmquist: Exploring Integrative Veterinary Practice
Dr. Nalini Chilkov: 10 Reasons You Should Be Tested for Vitamin D
http://bit.ly/8DT43r
CONCLUSION: Calcium stone formers with a low lumbar BMD exhibit a blunted response of PTH release and an apparently overshooting production of 1.25 vitamin D following a low-calcium diet.
PMID: 18398019
Apparently stone formers have a genetic predisposition. Likely the best thing they can do
is maintain a steady intake of the vitamin and calcium with an ample liquids regimen every
day of their lives, IMO on a first blush quick scan of part of the article. Read the article by way of Pubmed links.
onto the web has some glaring typo.
In some of our furry friends there is a difference between the two forms and other animals vitamin D2 is frankly inactive.
Discrimination against ergocalciferol by cats appears to result from differences in affinity of the binding protein for the metabolites of the two forms of vitamin D. These results indicate that cats discriminate against ergocalciferol, and use it with an efficiency of 0.7 of that of cholecalciferol to maintain plasma 25-hydroxyvitamin D concentration.
PMID: 15379909
The assumption that vitamins D2 and D3 have equal nutritional value is probably wrong and should be reconsidered.
PMID: 9771862
The above paper is good also in that it gives one an idea of how much a short course of
4000 IU might raises levels.
Even members of the committee that set this value have asked it be reviewed. Currently, a new committee has been assembled on the topic and in time will issue a ruling for all the pedagogues to repeat as if it is revealed truth from the great vitamin Diety.
However the "burn rate per day" for the vitamin is around 4000 IU and even higher in a lacating human female given that some of it is siphoned off into the mothers milk. And vitamin D2 has a shorter biological half life that vitamin D3. It low affinity of vitamin D2 to the respective serum binding program which is worrying. Bolus dosing with vitamin D2 is a discredited practice or should be as on a two week schedule with one bolus dose can actually lower 25 OH vitamin D3 levels at the end of two weeks.
In addition there is some evidence excess adipose tissue increases the rate of this vitamin's metabolism. While some have suspected this vitamin was just buried in the adipose this is apparently wrong. So we
who are overweight or those who are obese may need quite large doses to reach an optimal serum
level.
I noticed someone confusing preformed vitamin A to vitamin D on the issue of toxicity.
See you on the Usenet....................Trig
http://products.mercola.com/vitamin-d-spray/
Do I hear 2,000 IUs? 2000 IUs!
Do I hear 4,000?
What the hell ... 10,000. Every IU must go.
What increasing your vitamin d levels can do in a few people is reveal a pre-existing case of primary hyperparathyroid disease. This is hidden by the very low vitamin d levels, however, it is still causing damage so identifying it is an advantage. Secondary hyperparathyroid is actually treated by increasing a person's vitamin d levels.
There's a reason why no-one is suggesting it. Because it's a f'ing false claim:
Mayo Clinic: "The upper limit (UL) for vitamin D has been recommended as 2,000 IU daily due to toxicities that can occur when taken in higher doses."
Hmm ...
For instance testosterone. Just this week a new report found MEN WHO SUNBATHE have a higher testosterone level and a higher libido.
(not that that is always good!)
Link below. It is on the bottom of healthapalooza's front page.
www.healthapalooza.com
http://www.healthapalooza.com
By the way, I was already on the vitamin D3 but now I will up my daily dose to the recommended 4-6000 IUs per day
http://dietary-supplements.info.nih.gov/factsheets/vitamind.asp#h3
Recent assays of meat in New Zealand have reported levels of 0.10 [micro]g vitamin D3 and 0.45 [micro]g 25-OH D3 per 100 g in beef and levels of 0.04 and 0.93 [micro]g/100 g respectively in lamb. (21) Given the higher biological activity of the 25-OH vitamin D, this means that 100 g of cooked beef could provide 12% of the estimated adequate intake of 10 [micro]g/day for a 51- to 70-year-old individual, (8) and cooked lamb could provide more than 25%, and hence be an important source of this nutrient.
The 25-OH D3 is considered to be superior in biologically availability. That is why many sources such as this now cite that "Red meat is the largest natural source of vitamin D, an essential vitamin for maintenance of organs and our bones."
http://www.meateat.co.uk/vitamins-in-meat.html
I definitely agree that salmon and mackerel are great sources of vitamin D, but for many people, relying on sunlight alone with no dietary sources from the animal products that D comes from, and the saturated fat necessary for making D bioavailable, is a quick road to rickets. That is why vegan and macrobiotic children are particularly prone to developing rickets from a lack of vitamin D.
HuffPost has reported on this topic before. Check out this very informative post about Vit. D:
http://www.huffingtonpost.com/dr-frank-lipman/vitamin-d-what-you-need-t_b_308973.html
And if you rather watch video, youtube is loaded with Vitamin D info:
http://www.youtube.com/results?search_query=vitamin+d&search_type=&aq=f
Consider using D3 as opposed to D2 (these being the two different forms of Vit D). There is (naturally) a debate about which on is better, but what I've read suggests that D3 is better absorbed.
Vit D is but one of several very important natural supplements to consider: http://bit.ly/MustHaveVitamins
Jgarma
www.1wallmart.com/vitamin-a-d.php