Sookhaphahpdee Ltd., a little-known pharmaceutical firm in Bangkok, Thailand, has been working on a cancer treatments for decades and has amassed some extraordinary evidence for the effectiveness of its product Yaamet-Dor.
In 2007, the results of a a 4-year, population-based, double-blind, randomized, placebo-controlled trial that involved approximately 1,200 women were announced. It reported that Yaamet-Dor, at 1,100 units per day, led to a 60 percent reduction in cancer incidence.
The Ready Availability of Yaamet-Dor
Before there is a frenzy for Yaamet-Dor and a run on Sookhaphahpdee's stock, let me come clean. There is no Sookhaphahpdee Ltd. (the word means good health in Thai), but the alleged product Yahmet-Dor (Yahmet means pill, Dor is D) is real as are the results cited above.
Moreover, despite ever-increasing indications of its effectiveness, it is something for which no pharmaceutical company can charge you. Yahmet-Dor is simply vitamin D! Essential to a whole array of biological processes, it's available in inexpensive pill form and at still-less cost from the sun, say in Thailand or even in Central Park.
I should begin by recalling that supplements do not enjoy a good reputation.
Over the years many have been touted, the vast majority are ineffective, and some are harmful. Vitamins A, C and E have all failed to live up to their exaggerated early promise. And Quackwatch.com and other sites do a good, albeit sometimes over-zealous job of critically examining bogus claims about a variety of other supplements.
Normally I'm sympathetic to the debunkers. In the case of vitamin D, however, there seems to be too much evidence and too many tantalizing studies coming out almost weekly for a facile dismissal of the claim that it may significantly reduce the incidence of not only cancer, but also a host of other conditions.
Some of the Evidence in Favor of Vitamin D
The Journal of the American College of Cardiology recently reported that people with vitamin D deficiencies, for example, double their chances of suffering a heart attack or stroke within five years.
This column is called "Who's Counting" and in the case of vitamin D and cancer, the counters are Drs. Ingraham, Bragdon and Nohe, who reviewed the extensive medical literature on vitamin D published between 1970 and 2007.
In their 2008 survey article in Current Medical Research and Opinion, they concluded, "that efforts to improve vitamin D status would have significant protective effects against the development of cancer.
The clinical research community is currently revising recommendations for optimal serum levels and for sensible levels of sun exposure to levels greater than previously thought.
Currently, most experts in the field believe that intakes of between 1,000 and 4,000 International Units ... will offer significant protection effects against cancers of the breast, colon, prostate, ovary, lungs and pancreas."
Not All Studies Point in the Same Direction
Not every study is completely positive. In a large study, the National Cancer Institute found that blood levels of vitamin D higher than a certain moderate level were associated with a 72 percent risk reduction in colorectal cancer, but found no association between vitamin D blood levels and overall cancer mortality.
Studies on those taking more substantial doses of vitamin D have not been undertaken, however, and many researchers believe that the recommended daily allowance of 400 IU for vitamin D is woefully inadequate and that deficiencies are widespread.
There is epidemiological evidence as well. Pills and sunshine are the primary sources of the vitamin D (technically a hormone) and most of us no longer spend our working days outside.
Thus, the results of a 2006 study of cancer patients from over a dozen countries in the European Journal of Cancer were not too surprising. They pointed to a large difference in cancer risk between sunny and non-sunny countries for several different cancers.
Much Higher Recommended Daily Allowance Suggested
Of course, prospective, retrospective, and observational studies are always a bit dubious because of the effect of confounding variables, non-uniform dosages, the confirmation biases of the experimenter (not unrelated to those of the columnist), subjects' poor memories and the like.
Their prevalence in the medical literature is one reason for the often seemingly contradictory conclusions announced. (How many epidemiologists does it take to change a light bulb? None. Their retrospective studies have already changed it.)
Thus, one of the most compelling studies of vitamin D is not of this sort. It is the 2007 four-year, double-blind, randomized, placebo-controlled trial conducted by Drs. Lappe, Travers-Gustafson, Davies, Recker and Heaney and involving approximately 1,200 women.
Cited at the beginning of this column, the study appeared in the American Journal of Clinical Nutrition and called for either 1,100 international units of vitamin D per day (not the the present RDA of 400 IU) and some calcium or else just the placebo.
The women were over 55 and from a nine-county area of rural Nebraska and the reduction of all-cancer incidence (I stress all-cancer incidence) for those taking the vitamin D supplements was, as noted, 60 percent for the four years and a whopping 77 percent for the last three years.
This bears reiteration. The women taking 1,100 IU of vitamin D developed less than one quarter of the cancers developed by women in the control group.
Since vitamin D is safe and cheap, many of those involved in the studies above suggest that there is every reason for people to increase their intake of vitamin D supplements. There is certainly every reason but one to investigate them further.
The purpose of my fictional introduction above is not only to defamiliarize vitamin D, but also to underline that reason. As is the case with aspirin, there unfortunately isn't much economic incentive to conclusively demonstrate the effectiveness of much higher doses of vitamin D.
The primary incentive is a moral one. We want people to enjoy sookhaphahpdee.
John Allen Paulos, a professor of mathematics at Temple University, is the author of the best-sellers "Innumeracy" and "A Mathematician Reads the Newspaper," as well as (just out in paperback) "Irreligion: A Mathematician Explains Why The Arguments for God Just Don't Add Up." His "Who's Counting?" column on ABCNews.com appears the first weekend of every month.