Re: Re: Vitamin D yet again

[Guest guest]

AFAIK there is a significant difference between ingesting Vitamin D supplements

and sunlight exposure.

There have also been some questions about early tests related to formulations.

Most fat soluble Vitamins like D have upper limits for safe dosing, AFAIK

precursors for such are not

the same since the body apparently regulates production of the final vitamins

when you have what you need.

Similar to beta carotene being healthy in massive doses but Vitamin A having

upper safety limits.

I suspect sun exposure is similar to eating a precursor for Vit D. That said

there are the obvious

exposure limits due to skin damage.

There is an excellent book on the subject but the title/author escapes me. It

may be Stoll but I can't swear to that.

JR

-----Original Message-----

From: citpeks [mailto:citpeks@...]

Sent: Tuesday, April 05, 2005 2:09 PM

Subject: [ ] Re: Vitamin D yet again

I think some of the statements in the article by Sally Squires cannot

be taken as authoritative. Consider the following two inconsistent

statements:

1) 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.

2) 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.

This would imply that a 15-minute exposure to the sunlight could be

toxic. Very doubtful!

Tony

[Guest guest]

Journal of the American Academy of DermatologyVolume 51 • Number 1 • July 2004Copyright © 2004 American Academy of Dermatology, Inc.

Letters

The vitamin D dilemma

Holick[1] also offers helpful clinical guidelines of UVR vitamin D equivalencies. For example, 1 minimal erythema dose of sun in a bathing-suit distribution equals 10,000 IU of oral vitamin D, and 1 minimal erythema dose of UVR administered to 6% to 10% of the body equals 600 to 1000 IU of oral vitamin D. Exposure of hands, arms, and face 2 to 3 times a week to one third to one half minimal erythema dose of spring or autumn sun is sufficient to satisfy daily vitamin requirements. Alternatively, 5 minutes of July sun at noon in Boston, Mass, suffices for individuals with skin type II.

regards.

----- Original Message -----

From: Rodney

Sent: Tuesday, April 05, 2005 2:20 PM

Subject: [ ] Re: Vitamin D yet again

Hi Tony:And in addition the information regarding 20,000 units of vitamin D is worthless in the absence of specifying whether the person is required to be naked, face and arms exposed, or hiding in a cupboard, or what?The number of IU per minute per square foot would have been helpful. Then we would have something to work with.Rodney.> > I think some of the statements in the article by Sally Squires cannot> be taken as authoritative. Consider the following two inconsistent> statements:> > 1) 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.> > 2) 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.> > This would imply that a 15-minute exposure to the sunlight could be> toxic. Very doubtful!> > Tony