Vitamin D and Cancer
March 15, 2004
Information Regarding Vitamin D
Here are two interesting articles regarding vitamin D and cancer: Vitamin D ... In Need of Revision. and Vitamin D Nutrition and Its Potential Health Benefits for Bone, Cancer and Other Conditions. The first of these articles is by Dr. Ben Treadwell, a former Associate Professor with the Harvard Medical School. Dr. Treadwell is involved with the alpha lipoic acid and acetyl-l-carnitine work initiated by Ds. Bruce Ames (UC - Berkeley) and Dr. Tory Hagen (Linus Pauling Institute). The second paper is self-explanatory.
The second paper draws a vitally important distinction between the two kinds of vitamin D commonly found in vitamin D supplements: vitamin D2 (ergocalciferol), extracted from yeast and not found in mammals, and vitamin D3 (cholecalciferol). The authors estimate that vitamin D2 is about ¼ as effective as vitamin D3. However, no distinction is made in specifying vitamin D supplementation between vitamin D2 and vitamin D3, and in Australia, vitamin D3 is unavailable. Only the weaker D2 version can be sold without a prescription.
Both of these papers suggest that vitamin recommended daily allowances are too low (by a factor of 10 or more), and that in the future, they will probably eventually be greatly increased. (As John Maynard Keynes said about the word eventually, "Eventually, we'll all be dead.")
All of our vitamin D supplements are comprised of vitamin D3 (cholecalciferol).
Update, March 17:
The authors of the second paper, Vitamin D Nutrition and Its Potential Health Benefits for Bone, Cancer and Other Conditions, recommend vitamin D intakes of 1,000 I. U. a day or more. They point out that someone who works outside will typically obtains 4,000 I. U. a day from sunlight. They observe that elevated serum and urinary calcium levels don't occur in adults below 40,000 I. U. a day, and then only over a period of several months..
Serum levels of vitamin D are a logarithmic function of vitamin D intake.
Tommie and I are upping our doses to a bit above 1,000 I. U. a day. (We may eventually check our circulating vitamin D levels and our calcium levels, although we wouldn't expect much change immediately.)
Update, March 23:
Further investigation underscores the importance of vitamin D. In response to dermatologists' urgings to avoid the sun at all times, most U. S. citizens are now vitamin-D deficient. Rickets is showing up again in children. This is another case (in my opinion) of humanity tampering blindly with nature. Some of us developed white skins because nature killed our darker cousins who couldn't synthesize as much vitamin D as our ancestors could. And we would have spent a lot of time in the sun in those Stone Age days. So getting enough vitamin D is critical. The death rate from non-melanoma skin cancer is estimated at something like 1/1,000th of the death rate from other cancers attributable to vitamin D deficiency. Vitamin D is highly protective against multiple sclerosis, rheumatoid arthritis, osteoarthritis, hypertension, Crohn's disease. inflammatory bowel disease, and other autoimmune diseases, as well as cancer. It's also reputedly protective against cardiovascular disease. In principle, we can get it through supplements, but the British are recommending up to 1,000 I. U. a day. The U. S. says that up to 2,000 I. U. a day is safe. Several vitamin D experts are saying that we need at least 4,000 I. U. a day, and that we can easily get that by exposure to the sun.
It makes sense to me to cover my head and to apply sunscreen to my face, ears, and the top of my head, and I do that. However, I've spent a lot of my time outdoors in the sun, and the worst I've had to show for it are some actinic keratoses, all of which were on my head and my ears. They were removed, and currently, I don't have anything brewing there. There's nothing that should keep me from sunning my back, my chest, or the undersides of my arms. I'll hold down my exposure to something like 10 minutes at a time on each side. It would be decades before I should have to worry about skin cancer with that kind of mild exposure, and in the meantime, I'll be topping off my oral intake of vitamin D with solar exposure. Maybe in a few more years, with the vitamin D experts pushing for higher levels of vitamin D consumption, the vitamin D intake guidelines will be revised upward, and it will be more socially acceptable to up our vitamin D supplementation. But even so, I'll bet that we haven't yet heard all the reasons why we're designed to get some sunlight. We were born to run, and to run in the sun, and there is probably another reason or two for this, besides getting enough vitamin D.