Wikipedia iz fun:

Health benefits

The skin produces vitamin D in response to sun exposure (in particular, UVB in the 295-297 nm range),[4][5] which can be a health benefit for those with vitamin D deficiency. In 2002, Dr. William B. Grant published an article claiming that 23,800 premature deaths occur in the US annually from cancer due to insufficient UVB exposures (apparently via vitamin D deficiency). [6] This is higher than 8,800 deaths that occurred from melanoma or squamous cell carcinoma. This does not mean that sun tanning is categorically safe or beneficial. Spending several minutes in the sun is long enough to obtain your daily dose of vitamin D. Other research [7][8] estimates that 50,000–63,000 individuals in the United States and 19,000 - 25,000 in the UK die prematurely from cancer annually due to insufficient vitamin D.

Another effect of vitamin D deficiency is osteomalacia, which can result in bone pain, difficulty in weight bearing and sometimes fractures. This work has been updated in Grant et al. 2005[9] and Grant and Garland, 2006. [10] In addition, it was reported that in Spain, risk of non-melanoma skin cancer is balanced by reduced risk of 16 types of cancer [Grant, 2006][11]

According to research conducted in 2007 by Cozen, Gauderman, Islam, and Mack,[12][13] sun exposure during childhood prevents multiple sclerosis later in life.

Huh, its like we're taking it too far. How unlike us...

I saw some ad for sun blocking clothing that would prevent 87% of rays from touching your skin... um, isn't that just "clothing"?

Huh, its like we're taking it too far. How unlike us...

I take vit. D supplements, because my doc did some tests and found out my vit. D levels were, erm, freakishly low. What? Giant burny thing in the sky! It frightens me!

Since I need SPF 15 to even turn on an indoor light

Ah-Ha! You are using light bulbs!

It's my employers, man. I'm just a cog in their electron-exploiting ways.

I saw some ad for sun blocking clothing that would prevent 87% of rays from touching your skin... um, isn't that just "clothing"?

Actually, no. It depends on how tight the weave is, and how thick or thin the fabric is. A man's white undershirt -- the kind that comes in a 3-pack -- won't block the sun for much longer than SPF 15 will.

(I know I sound like Cliff Claven, but srsly. I burn in about 8 minutes, so I know lots of info about how not to.)

Despite not getting her red hair, I did get my mom's sunburning gene. To answer Trudy's question, you can get burns through clothes.

I live in Florida.

We still sell Hawaiian Tropic and Panama Jack oil round these parts.

A white man's undershirt -- the kind that comes in a 3-pack -- won't block the sun for much longer than SPF 15 will.

Huh. That reminds me when I used to get a farmer's tan all the time from working in the fields (driving a tractor or swather) while in a white t-shirt.

A white man's undershirt -- the kind that comes in a 3-pack -- won't block the sun for much longer than SPF 15 will.

Huh. That reminds me when I used to get a farmer's tan all the time from working in the fields (driving a tractor or swather) while in a white t-shirt.

Hmm. Just me, I guess. Like I said, I burn easily.

I could be full of shit and not know what the hell I'm talking about.

t edit Although I didn't mean to imply that an undershirt lets through as much UVA/UVB as you'd get without a shirt at all, and without sunblock. Just that you standard t-shirt isn't as good of a block as you might think.

And I have gotten burned through a t-shirt, but I'm a melanin-deprived weirdo.

Well, when I was a kid I'd get burned a few times each spring/summer until I built up a dark enough tan....

Hmm. Just me, I guess. Like I said, I burn easily.

Not just you. I totally have to dress for sun.

I'm sure some people CAN burn through clothing with an open weave... so just buy stuff that's not open-weave. Someone needs an entire catalog for that?

I take vit. D supplements, because my doc did some tests and found out my vit. D levels were, erm, freakishly low. What? Giant burny thing in the sky! It frightens me!

Because its trying to GET you. That's why.