[Ted_Hutchinson]

Is it possible that one may not absorb vit. D?

Sure I've put some links on another post showing this happens. If you can stand MERCOLA then watch Shocking Update -- Sunshine Can Actually Decrease Your Vitamin D Levels for one explanation. But it's not entirely that simple. Our inflammatory status may not only affect the rate of use of D3, it's absorption from the surface of the skin but also it's actual metabolism on the skin. So it's only by regular25(OH)D testing that you can be sure how your body actually responds to either UVB, supplements or both.

I live in South Florida, worked many years outside without sunscreen and still diagnosed w/breast cancer.

No one is suggesting that raising vitamin d status to @55ng/mL will prevent all cases of BC. Only that those with higher levels have a lower rate of incidence and those diagnosed/treated when levels are high generally have a better prognosis.

Remember Vitamin D synthesis on the skin is a heat driven self limiting process.Good description of what happens here
Previtamin D3 is produced very rapidly and accumulates in the skin. Its conversion to vitamin D3 is a much slower, heat dependent process. One might expect huge quantities of preD3 to build up, but this does not happen. This is because preD3 is also sensitive to ultraviolet light up to 325nm; a proportion is converted quite rapidly into two biologically inactive products, lumisterol3 and tachysterol3. These also accumulate in the skin.......However, should excess vitamin D3 build up in the skin - if, for example, more is produced than the binding protein can remove - ultraviolet light breaks this down, as well, into three new substances: two suprasterols and 5,6 trans-vitamin D. This latter product does have some biological activity; the others are believed to be inert

My grandfather was a farmer, exposed to sunshine out in the fields most of his life, he dies of brian cancer, my mom, spent most of her days at the beach without sunscreen and diagnosed w/breast cancer at age 51. My family and myself, exposed to plenty of sunshine in South Florida without sunscreens and yet so much cancer!

These sound very much like people spending too much time under the sun. At your latitude the skin color of the Indigenous people would have provided adequate protection from long exposures but for Caucasian skins they need short unprotected full body sun
exposure then cover up or go indoors.
This calculator will enable you to work out a safe time however be aware that awareness of the need for higher vitamin d intakes has moved on since 2005 and you may have to adjust the calculator to ensure you are getting 5000iu/daily not just 1000iu.

there's still nothing solid about vitamin d and cancer prevention.

I think cancer specialists will be the last to acknowledge the proven link. It's human nature not to want to accept your role in perpetuating dangerously misguided information. Cancer UK have in my opinion been responsible for bad advice leading to the rises in cancer incidence over the years particularly with their advice against UVB exposure. They are shifting their ground somewhat but still have way to go.

It's a bit like the bankers and the bonus culture leading to financial meltdown. Do we see a banking industry that has accepted they made mistakes and have changed their ways, or are they still trying to perpetuate a culture that provides huge financial rewards for themselves?

There is absolutely no money to be made from vitamin D3 usage. No one can patent it, no one can make major profits from it's use.
If spending 2.5p daily on 5000iu/daily vitamin D3 prevents cancer it's going to cost a lot of financial consequences to the drug industry that will seriously impact on health professionals careers and financial rewards.

We are as likely to see the cancer industry embracing vitamin d3 as we are seeing the banking industry embrace a bonus free culture.