Re: Another Vitamin D Benefit

November 6, 2005

Interesting that the doctor quoted in the article says we need relatively little Vit D, and yet we've had postings that there's a deficiency in most people.

on 11/6/2005 4:05 PM, Rodney at perspect1111@... wrote:

http://news.bbc.co.uk/2/hi/health/4458085.stm

November 6, 2005

Interesting that the doctor quoted in the article says we need relatively little Vit D, and yet we've had postings that there's a deficiency in most people.

on 11/6/2005 4:05 PM, Rodney at perspect1111@... wrote:

http://news.bbc.co.uk/2/hi/health/4458085.stm

November 7, 2005

FYI:

Cancer Epidemiol Biomarkers Prev. 2005 Oct;14(10):2303-9.

Vitamin D is associated with improved survival in early-stage non-small cell lung cancer patients.Zhou W, Suk R, Liu G, Park S, Neuberg DS, Wain JC, Lynch TJ, Giovannucci E, Christiani DC.Occupational Health Program, Department of Environmental Health, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115, USA.Vitamin D may inhibit the development and progression of a wide spectrum of cancers. We investigated the associations of surgery season and vitamin D intake with recurrence-free survival (RFS) and overall survival in 456 early-stage non-small cell lung cancer patients. The data were analyzed using log-rank test and proportional hazards models. The median (range) follow-up time was 71 (0.1-140) months, with 161 recurrence and 231 deaths. Patients who had surgery in summer had a better RFS than those who had surgery in winter (adjusted hazard ratio, 0.75; 95% confidence interval, 0.56-1.01), with 5-year RFS rates of 53% (45-61%) and 40% (32-49%), respectively (P = 0.10, log-rank test). Similar association between surgery season and RFS was found among the 321 patients with dietary information (P = 0.33, log-rank test). There was no statistically significant association between vitamin D intake and RFS. Because both season and vitamin D intake are important predictors for vitamin D levels, we investigated the joint effects of surgery season and vitamin D intake. Patients who had surgery during summer with the highest vitamin D intake had better RFS (adjusted hazard ratio, 0.33; 95% confidence interval, 0.15-0.74) than patients who had surgery during winter with the lowest vitamin D intake, with the 5-year RFS rates of 56% (34-78%) and 23% (4-42%), respectively. Similar associations of surgery season and vitamin D intake with overall survival were also observed. In conclusion, the joint effects of surgery season and recent vitamin D intake seem to be associated with the survival of early-stage non-small cell lung cancer patients.PMID: 16214909

Re: [ ] Another Vitamin D Benefit

Interesting that the doctor quoted in the article says we need relatively little Vit D, and yet we've had postings that there's a deficiency in most people.on 11/6/2005 4:05 PM, Rodney at perspect1111@... wrote:

http://news.bbc.co.uk/2/hi/health/4458085.stm

November 7, 2005

FYI:

Cancer Epidemiol Biomarkers Prev. 2005 Oct;14(10):2303-9.

Vitamin D is associated with improved survival in early-stage non-small cell lung cancer patients.Zhou W, Suk R, Liu G, Park S, Neuberg DS, Wain JC, Lynch TJ, Giovannucci E, Christiani DC.Occupational Health Program, Department of Environmental Health, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115, USA.Vitamin D may inhibit the development and progression of a wide spectrum of cancers. We investigated the associations of surgery season and vitamin D intake with recurrence-free survival (RFS) and overall survival in 456 early-stage non-small cell lung cancer patients. The data were analyzed using log-rank test and proportional hazards models. The median (range) follow-up time was 71 (0.1-140) months, with 161 recurrence and 231 deaths. Patients who had surgery in summer had a better RFS than those who had surgery in winter (adjusted hazard ratio, 0.75; 95% confidence interval, 0.56-1.01), with 5-year RFS rates of 53% (45-61%) and 40% (32-49%), respectively (P = 0.10, log-rank test). Similar association between surgery season and RFS was found among the 321 patients with dietary information (P = 0.33, log-rank test). There was no statistically significant association between vitamin D intake and RFS. Because both season and vitamin D intake are important predictors for vitamin D levels, we investigated the joint effects of surgery season and vitamin D intake. Patients who had surgery during summer with the highest vitamin D intake had better RFS (adjusted hazard ratio, 0.33; 95% confidence interval, 0.15-0.74) than patients who had surgery during winter with the lowest vitamin D intake, with the 5-year RFS rates of 56% (34-78%) and 23% (4-42%), respectively. Similar associations of surgery season and vitamin D intake with overall survival were also observed. In conclusion, the joint effects of surgery season and recent vitamin D intake seem to be associated with the survival of early-stage non-small cell lung cancer patients.PMID: 16214909

Re: [ ] Another Vitamin D Benefit

Interesting that the doctor quoted in the article says we need relatively little Vit D, and yet we've had postings that there's a deficiency in most people.on 11/6/2005 4:05 PM, Rodney at perspect1111@... wrote:

http://news.bbc.co.uk/2/hi/health/4458085.stm

November 7, 2005

It occurs to me that older people seem to die more freq in the winter. So the vit D lack makes sense to me. I recall some suggestions as high as 4000 IU.

A previous post:

> > >> The skin's ability to make vitamin D declines significantly with age. For> > >> this reason, the National Academy of Sciences (NAS) set the latest vitamin D> > >> daily intake on an age-related scale: 200 International Units (IU) --> > >> about the amount found in two eight-ounce glasses of milk -- for those 19> > >> to 50 years of age; 400 IU for those aged 51 to 70 years; and 600 IU for> > >> people 70 and older. The NAS also set a tolerable upper intake of 2,000 IU> > >> for adults. Toxic levels have been reported at 10,000 IU or higher per day.> > >>> > >> But a growing number of scientists believe that vitamin D intake should be> > >> at least 1,000 IU or higher.> > >>> > >> "Fifty years ago, a bunch of guys got in a room and said, 'We know that a> > >> teaspoon of cod liver oil cures rickets in a child and it has 400 IU of> > >> vitamin D,' " said Bruce Hollis, a professor of pediatrics, biochemistry and> > >> molecular biology at the Medical University of South Carolina. "They> > >> transposed that amount onto adults. It was arbitrarily set with no evidence> > >> [in adults] at all."> > >>> > >> Where research once suggested a limited health role for vitamin D, today> > >> there is increasing evidence that it protects against breast, colon and> > >> prostate cancer. Population studies show that people with the highest> > >> vitamin D levels are less likely to develop multiple sclerosis, lupus,> > >> rheumatoid arthritis and other autoimmune diseases than those with lower> > >> levels. Plus it appears that vitamin D may protect against heart disease,> > >> type 2 diabetes and the insulin resistance that precedes it.> > >>> > >> "If just half the chronic diseases laid at the feet of vitamin D pan out,> > >> it will be quite significant," said P. Heaney, a professor of> > >> medicine at Creighton University in Omaha and a proponent for increasing> > >> vitamin D intake.> > >>> > >> Just a decade ago, scientists developed an inexpensive blood test that more> > >> accurately determines vitamin D status. Use of that test revealed widespread> > >> deficiencies and led the NAS to note in 1997 that vitamin D "deficiency is> > >> now a significant concern in adults over the age of 50 years who live in the> > >> northern industrialized cities of the world."> > >>> > >> In 2004, the dietary guidelines scientific committee concluded the elderly,> > >> people with dark skin and those exposed to insufficient sunlight "are at> > >> risk of being unable to maintain vitamin D status" and may "need> > >> substantially more than" the 1997 recommendations called for.> > >>> > >> But some doctors worry that the evidence is still preliminary. Few if any> > >> studies "show that people are having problems with the lower limits of> > >> vitamin D being where they are," said New York University dermatologist> > >> Darrel Rigel, a past president of the American Academy of Dermatology.> > >>> > >> Dermatologists are particularly concerned that raising the vitamin D> > >> recommendation might tempt some people to spend more time in the sun or in> > >> tanning booths, thus increasing their risk of skin cancer. "Our> > >> recommendation is to take either vitamin pills or eat food that we know has> > >> higher levels of vitamin D," rather than increase sun exposure, said Henry> > >> Lim, chairman of dermatology at the Henry Ford Hospital in Detroit.> > >>> > >> Here's how to boost vitamin D levels safely:> > >>> > >> Drink vitamin D fortified beverages. While diet alone is unlikely to get> > >> you to the levels needed, drinking milk and other vitamin D fortified> > >> beverages will help. Some juice and soy milk is also fortified. An 8-ounce> > >> glass of any of these beverages delivers about 100 IU, or about half the> > >> intake recommended daily for adults 19 to 50 years of age; a quarter of the> > >> amount for adults 51 to 70; and just a sixth of the intake for those 70 and> > >> older. Yogurt and cheese are not fortified with vitamin D.> > >>> > >> Eat more herring and sardines. An ounce of pickled herring has nearly> > >> 200 IU of vitamin D. Two small sardines have 65 IU. But not all fish> > >> contains vitamin D. Salmon and tuna, for example, have none.> > >>> > >> Breakfast on fortified cereal or cereal bars. A cup of vitamin D> > >> fortified cereal delivers about 40 to 60 IU of vitamin D. Fortified cereal> > >> bars have even less: about 30 IU per bar.> > >>> > >> Take a multivitamin or other supplement. Most multivitamins, even the> > >> ones aimed at seniors, provide 400 IU of vitamin D, which won't cover those> > >> 70 and older. Some vitamin and health food stores sell gelcaps of vitamin D> > >> supplements that range from 700 IU to 2,000 IU. "The most practical way to> > >> increase our vitamin D levels is from supplements," said Harvard's Willett.> > >>> > >> Fun in the sun. Fifteen minutes of peak sun exposure without sunscreen> > >> allows a light-skinned person to make about 20,000 IU of vitamin D,> > >> according to Hollis. But much of that dose quickly "goes away," he said.> > >> You'd need such exposures at least every few days in order to sustain> > >> adequate levels. Since regular sun exposure increases skin cancer risk,> > >> "it's okay to expose yourself a little to the sun," said Henry Ford's Lim,> > >> "but not too much."

Regards.

Re: [ ] Another Vitamin D Benefit

Interesting that the doctor quoted in the article says we need relatively little Vit D, and yet we've had postings that there's a deficiency in most people.on 11/6/2005 4:05 PM, Rodney at perspect1111@... wrote:

http://news.bbc.co.uk/2/hi/health/4458085.stm

November 7, 2005

It occurs to me that older people seem to die more freq in the winter. So the vit D lack makes sense to me. I recall some suggestions as high as 4000 IU.

A previous post:

> > >> The skin's ability to make vitamin D declines significantly with age. For> > >> this reason, the National Academy of Sciences (NAS) set the latest vitamin D> > >> daily intake on an age-related scale: 200 International Units (IU) --> > >> about the amount found in two eight-ounce glasses of milk -- for those 19> > >> to 50 years of age; 400 IU for those aged 51 to 70 years; and 600 IU for> > >> people 70 and older. The NAS also set a tolerable upper intake of 2,000 IU> > >> for adults. Toxic levels have been reported at 10,000 IU or higher per day.> > >>> > >> But a growing number of scientists believe that vitamin D intake should be> > >> at least 1,000 IU or higher.> > >>> > >> "Fifty years ago, a bunch of guys got in a room and said, 'We know that a> > >> teaspoon of cod liver oil cures rickets in a child and it has 400 IU of> > >> vitamin D,' " said Bruce Hollis, a professor of pediatrics, biochemistry and> > >> molecular biology at the Medical University of South Carolina. "They> > >> transposed that amount onto adults. It was arbitrarily set with no evidence> > >> [in adults] at all."> > >>> > >> Where research once suggested a limited health role for vitamin D, today> > >> there is increasing evidence that it protects against breast, colon and> > >> prostate cancer. Population studies show that people with the highest> > >> vitamin D levels are less likely to develop multiple sclerosis, lupus,> > >> rheumatoid arthritis and other autoimmune diseases than those with lower> > >> levels. Plus it appears that vitamin D may protect against heart disease,> > >> type 2 diabetes and the insulin resistance that precedes it.> > >>> > >> "If just half the chronic diseases laid at the feet of vitamin D pan out,> > >> it will be quite significant," said P. Heaney, a professor of> > >> medicine at Creighton University in Omaha and a proponent for increasing> > >> vitamin D intake.> > >>> > >> Just a decade ago, scientists developed an inexpensive blood test that more> > >> accurately determines vitamin D status. Use of that test revealed widespread> > >> deficiencies and led the NAS to note in 1997 that vitamin D "deficiency is> > >> now a significant concern in adults over the age of 50 years who live in the> > >> northern industrialized cities of the world."> > >>> > >> In 2004, the dietary guidelines scientific committee concluded the elderly,> > >> people with dark skin and those exposed to insufficient sunlight "are at> > >> risk of being unable to maintain vitamin D status" and may "need> > >> substantially more than" the 1997 recommendations called for.> > >>> > >> But some doctors worry that the evidence is still preliminary. Few if any> > >> studies "show that people are having problems with the lower limits of> > >> vitamin D being where they are," said New York University dermatologist> > >> Darrel Rigel, a past president of the American Academy of Dermatology.> > >>> > >> Dermatologists are particularly concerned that raising the vitamin D> > >> recommendation might tempt some people to spend more time in the sun or in> > >> tanning booths, thus increasing their risk of skin cancer. "Our> > >> recommendation is to take either vitamin pills or eat food that we know has> > >> higher levels of vitamin D," rather than increase sun exposure, said Henry> > >> Lim, chairman of dermatology at the Henry Ford Hospital in Detroit.> > >>> > >> Here's how to boost vitamin D levels safely:> > >>> > >> Drink vitamin D fortified beverages. While diet alone is unlikely to get> > >> you to the levels needed, drinking milk and other vitamin D fortified> > >> beverages will help. Some juice and soy milk is also fortified. An 8-ounce> > >> glass of any of these beverages delivers about 100 IU, or about half the> > >> intake recommended daily for adults 19 to 50 years of age; a quarter of the> > >> amount for adults 51 to 70; and just a sixth of the intake for those 70 and> > >> older. Yogurt and cheese are not fortified with vitamin D.> > >>> > >> Eat more herring and sardines. An ounce of pickled herring has nearly> > >> 200 IU of vitamin D. Two small sardines have 65 IU. But not all fish> > >> contains vitamin D. Salmon and tuna, for example, have none.> > >>> > >> Breakfast on fortified cereal or cereal bars. A cup of vitamin D> > >> fortified cereal delivers about 40 to 60 IU of vitamin D. Fortified cereal> > >> bars have even less: about 30 IU per bar.> > >>> > >> Take a multivitamin or other supplement. Most multivitamins, even the> > >> ones aimed at seniors, provide 400 IU of vitamin D, which won't cover those> > >> 70 and older. Some vitamin and health food stores sell gelcaps of vitamin D> > >> supplements that range from 700 IU to 2,000 IU. "The most practical way to> > >> increase our vitamin D levels is from supplements," said Harvard's Willett.> > >>> > >> Fun in the sun. Fifteen minutes of peak sun exposure without sunscreen> > >> allows a light-skinned person to make about 20,000 IU of vitamin D,> > >> according to Hollis. But much of that dose quickly "goes away," he said.> > >> You'd need such exposures at least every few days in order to sustain> > >> adequate levels. Since regular sun exposure increases skin cancer risk,> > >> "it's okay to expose yourself a little to the sun," said Henry Ford's Lim,> > >> "but not too much."

Regards.

Re: [ ] Another Vitamin D Benefit

Interesting that the doctor quoted in the article says we need relatively little Vit D, and yet we've had postings that there's a deficiency in most people.on 11/6/2005 4:05 PM, Rodney at perspect1111@... wrote:

http://news.bbc.co.uk/2/hi/health/4458085.stm

November 7, 2005

>>>I recall some suggestions as high as 4000 IU.

The dose of vitamin D at 800 IU daily was not determined scientifically but

determined arbitrarily before sufficient scientific methodology was

available.2-4 Heaney et al determined the physiological requirement of vitamin D

by showing that healthy men use 4000 IU cholecalciferol daily,2 an amount that

is safely attainable with supplementation3 and often exceeded with exposure of

the total body to equatorial sun.4

2. Heaney RP, Davies KM, Chen TC, Holick MF, Barger-Lux MJ. Human serum

25-hydroxycholecalciferol response to extended oral dosing with cholecalciferol.

Am J Clin Nutr 2003;77: 204-10.

4. Vieth R. Vitamin D supplementation, 25-hydroxyvitamin D concentrations, and

safety. Am J Clin Nutr 1999;69: 842-56.

November 7, 2005

>>>I recall some suggestions as high as 4000 IU.

The dose of vitamin D at 800 IU daily was not determined scientifically but

determined arbitrarily before sufficient scientific methodology was

available.2-4 Heaney et al determined the physiological requirement of vitamin D

by showing that healthy men use 4000 IU cholecalciferol daily,2 an amount that

is safely attainable with supplementation3 and often exceeded with exposure of

the total body to equatorial sun.4

2. Heaney RP, Davies KM, Chen TC, Holick MF, Barger-Lux MJ. Human serum

25-hydroxycholecalciferol response to extended oral dosing with cholecalciferol.

Am J Clin Nutr 2003;77: 204-10.

4. Vieth R. Vitamin D supplementation, 25-hydroxyvitamin D concentrations, and

safety. Am J Clin Nutr 1999;69: 842-56.

November 7, 2005

One more..

>> I recall some suggestions as high as 4000 IU.

Additionally, we also now realize that the Food and Nutrition Board's previously

defined Upper Limit (UL) for safe intake at 2,000 IU/day was set

far too low and that the physiologic requirement for vitamin D in

adults may be as high as 5,000 IU/day, which is less than half of

the >10,000 IU that can be produced endogenously with full-body

sun exposure.1,2

1. Vieth R. Vitamin D supplementation, 25-hydroxyvitamin D concentrations, and

safety. Am J

Clin Nutr. 1999;69(5):842-56.

2. Heaney RP, Davies KM, Chen TC, Holick MF, Barger-Lux MJ. Human serum

25-hydroxycholecalciferol

response to extended oral dosing with cholecalciferol. Am J Clin

Nutr.2003;77(1):204-10.

http://www.bioticsresearch.com/PDF/Vitamin%20D%20ATHM2004%20Vasquez.pdf

November 7, 2005

One more..

>> I recall some suggestions as high as 4000 IU.

Additionally, we also now realize that the Food and Nutrition Board's previously

defined Upper Limit (UL) for safe intake at 2,000 IU/day was set

far too low and that the physiologic requirement for vitamin D in

adults may be as high as 5,000 IU/day, which is less than half of

the >10,000 IU that can be produced endogenously with full-body

sun exposure.1,2

1. Vieth R. Vitamin D supplementation, 25-hydroxyvitamin D concentrations, and

safety. Am J

Clin Nutr. 1999;69(5):842-56.

2. Heaney RP, Davies KM, Chen TC, Holick MF, Barger-Lux MJ. Human serum

25-hydroxycholecalciferol

response to extended oral dosing with cholecalciferol. Am J Clin

Nutr.2003;77(1):204-10.

http://www.bioticsresearch.com/PDF/Vitamin%20D%20ATHM2004%20Vasquez.pdf

November 7, 2005

Jeff Novick wrote:

>>>> I recall some suggestions as high as 4000 IU.

>

> The dose of vitamin D at 800 IU daily was not determined scientifically but

determined arbitrarily before sufficient scientific methodology was

available.2-4 Heaney et al determined the physiological requirement of vitamin D

by showing that healthy men use 4000 IU cholecalciferol daily,2 an amount that

is safely attainable with supplementation3 and often exceeded with exposure of

the total body to equatorial sun.4

>

> 2. Heaney RP, Davies KM, Chen TC, Holick MF, Barger-Lux MJ. Human serum

25-hydroxycholecalciferol response to extended oral dosing with cholecalciferol.

Am J Clin Nutr 2003;77: 204-10.

>

> 4. Vieth R. Vitamin D supplementation, 25-hydroxyvitamin D concentrations, and

safety. Am J Clin Nutr 1999;69: 842-56.

I've been busy so apologize if this has already been mentioned, but it

seems to me any discussion of dosing Vit D should account for

the individual's sunlight exposure. While I am a fan of getting 100%

the natural way, my neighbors appreciate that I don't get mine

au' natural.

AFAIK Vit D is Fat soluble so A) we can store it for cloudy days and

there can be too much of even this good thing.

JR

November 7, 2005

Jeff Novick wrote:

>>>> I recall some suggestions as high as 4000 IU.

>

> The dose of vitamin D at 800 IU daily was not determined scientifically but

determined arbitrarily before sufficient scientific methodology was

available.2-4 Heaney et al determined the physiological requirement of vitamin D

by showing that healthy men use 4000 IU cholecalciferol daily,2 an amount that

is safely attainable with supplementation3 and often exceeded with exposure of

the total body to equatorial sun.4

>

> 2. Heaney RP, Davies KM, Chen TC, Holick MF, Barger-Lux MJ. Human serum

25-hydroxycholecalciferol response to extended oral dosing with cholecalciferol.

Am J Clin Nutr 2003;77: 204-10.

>

> 4. Vieth R. Vitamin D supplementation, 25-hydroxyvitamin D concentrations, and

safety. Am J Clin Nutr 1999;69: 842-56.

I've been busy so apologize if this has already been mentioned, but it

seems to me any discussion of dosing Vit D should account for

the individual's sunlight exposure. While I am a fan of getting 100%

the natural way, my neighbors appreciate that I don't get mine

au' natural.

AFAIK Vit D is Fat soluble so A) we can store it for cloudy days and

there can be too much of even this good thing.

JR

November 7, 2005

>> While I am a fan of getting 100% the natural way, my neighbors appreciate

that I don't get mine

au' natural.

>>AFAIK Vit D is Fat soluble so A) we can store it for cloudy days and

there can be too much of even this good thing.

Right, but we dont need to expose our " total " selves " au natural " . We only

need to expose a percent of our skin (ie, our arms and legs) for around 10-20

minutes a day to do the job. Of course, this depends on skin type and color as

some are more sensitive and others more protective.

AFAIK, the body wont OD from " au natural " Vit D , but can from Vit D

supplements. The DRI values are

based on the absence of adequate exposure to sunlight.

Jeff

November 7, 2005

>> While I am a fan of getting 100% the natural way, my neighbors appreciate

that I don't get mine

au' natural.

>>AFAIK Vit D is Fat soluble so A) we can store it for cloudy days and

there can be too much of even this good thing.

Right, but we dont need to expose our " total " selves " au natural " . We only

need to expose a percent of our skin (ie, our arms and legs) for around 10-20

minutes a day to do the job. Of course, this depends on skin type and color as

some are more sensitive and others more protective.

AFAIK, the body wont OD from " au natural " Vit D , but can from Vit D

supplements. The DRI values are

based on the absence of adequate exposure to sunlight.

Jeff

November 7, 2005

Hi Jeff:

Many many thanks for those references. Here is the abstract of the

first one:

" Human serum 25-hydroxycholecalciferol response to extended oral

dosing with cholecalciferol.

Heaney RP, Davies KM, Chen TC, Holick MF, Barger-Lux MJ.

Creighton University, Omaha, NE 68131, USA. rheaney@...

BACKGROUND: The cholecalciferol inputs required to achieve or

maintain any given serum 25-hydroxycholecalciferol concentration are

not known, particularly within ranges comparable to the probable

physiologic supply of the vitamin. OBJECTIVES: The objectives were to

establish the quantitative relation between steady state

cholecalciferol input and the resulting serum 25-

hydroxycholecalciferol concentration and to estimate the proportion

of the daily requirement during winter that is met by cholecalciferol

reserves in body tissue stores. DESIGN: Cholecalciferol was

administered daily in controlled oral doses labeled at 0, 25, 125,

and 250 micro g cholecalciferol for approximately 20 wk during the

winter to 67 men living in Omaha (41.2 degrees N latitude). The time

course of serum 25-hydroxycholecalciferol concentration was measured

at intervals over the course of treatment. RESULTS: From a mean

baseline value of 70.3 nmol/L, equilibrium concentrations of serum 25-

hydroxycholecalciferol changed during the winter months in direct

proportion to the dose, with a slope of approximately 0.70 nmol/L for

each additional 1 micro g cholecalciferol input. The calculated oral

input required to sustain the serum 25-hydroxycholecalciferol

concentration present before the study (ie, in the autumn) was 12.5

micro g (500 IU)/d, whereas the total amount from all sources

(supplement, food, tissue stores) needed to sustain the starting 25-

hydroxycholecalciferol concentration was estimated at approximately

96 micro g (approximately 3800 IU)/d. By difference, the tissue

stores provided approximately 78-82 micro g/d. CONCLUSIONS: Healthy

men seem to use 3000-5000 IU cholecalciferol/d, apparently meeting >

80% of their winter cholecalciferol need with cutaneously synthesized

accumulations from solar sources during the preceding summer months.

Current recommended vitamin D inputs are inadequate to maintain serum

25-hydroxycholecalciferol concentration in the absence of substantial

cutaneous production of vitamin D. "

And here is the link to the full text:

http://www.ajcn.org/cgi/content/full/77/1/204

Also the abstract of the second:

" Vitamin D supplementation, 25-hydroxyvitamin D concentrations, and

safety.

Vieth R.

Department of Laboratory Medicine and Pathobiology, University of

Toronto, Mount Sinai Hospital, Ontario, Canada. rvieth@...

For adults, the 5-microg (200 IU) vitamin D recommended dietary

allowance may prevent osteomalacia in the absence of sunlight, but

more is needed to help prevent osteoporosis and secondary

hyperparathyroidism. Other benefits of vitamin D supplementation are

implicated epidemiologically: prevention of some cancers,

osteoarthritis progression, multiple sclerosis, and hypertension.

Total-body sun exposure easily provides the equivalent of 250 microg

(10000 IU) vitamin D/d, suggesting that this is a physiologic limit.

Sailors in US submarines are deprived of environmentally acquired

vitamin D equivalent to 20-50 microg (800-2000 IU)/d. The assembled

data from many vitamin D supplementation studies reveal a curve for

vitamin D dose versus serum 25-hydroxyvitamin D [25(OH)D] response

that is surprisingly flat up to 250 microg (10000 IU) vitamin D/d. To

ensure that serum 25(OH)D concentrations exceed 100 nmol/L, a total

vitamin D supply of 100 microg (4000 IU)/d is required. Except in

those with conditions causing hypersensitivity, there is no evidence

of adverse effects with serum 25(OH)D concentrations <140 nmol/L,

which require a total vitamin D supply of 250 microg (10000 IU)/d to

attain. Published cases of vitamin D toxicity with hypercalcemia, for

which the 25(OH)D concentration and vitamin D dose are known, all

involve intake of > or = 1000 microg (40000 IU)/d. Because vitamin D

is potentially toxic, intake of >25 microg (1000 IU)/d has been

avoided even though the weight of evidence shows that the currently

accepted, no observed adverse effect limit of 50 microg (2000 IU)/d

is too low by at least 5-fold. "

And the link to the full-text:

http://www.ajcn.org/cgi/content/full/69/5/842

The final sentance of the second abstract is especially interesting.

Rodney.

--- In , " Jeff Novick " <jnovick@p...>

wrote:

>

> >>>I recall some suggestions as high as 4000 IU.

>

> The dose of vitamin D at 800 IU daily was not determined

scientifically but determined arbitrarily before sufficient

scientific methodology was available.2-4 Heaney et al determined the

physiological requirement of vitamin D by showing that healthy men

use 4000 IU cholecalciferol daily,2 an amount that is safely

attainable with supplementation3 and often exceeded with exposure of

the total body to equatorial sun.4

>

> 2. Heaney RP, Davies KM, Chen TC, Holick MF, Barger-Lux MJ. Human

serum 25-hydroxycholecalciferol response to extended oral dosing with

cholecalciferol. Am J Clin Nutr 2003;77: 204-10.

>

> 4. Vieth R. Vitamin D supplementation, 25-hydroxyvitamin D

concentrations, and safety. Am J Clin Nutr 1999;69: 842-56.

>

November 7, 2005