Shedding light on vitamin D deficiency ‘crisis’

More on the cure du jour for the sick care faithful and additional proof they have no idea what a "healthy" supplement is.

"The vitamin D craze has been building over the last few years, with low levels of the supplement being the blamed as a source of many of our ills. Depression? D can ease it. Chronic pain? Take D. It is said to prevent kidney disease, diabetes, osteoporosis, colon and breast cancer, cardiovascular disease, or even the common cold. Recently, a study linked low vitamin D levels to the rise in Caesarean births...

Meanwhile, skeptics doubt many of the health claims and question the need and even the validity of widespread testing. They recall how large doses of vitamins C and E were supposed to prevent cardiovascular disease. Beta-carotene was supposed to prevent lung cancer. Selenium kept prostate cancer at bay. None of it turned out to be true, and some of the advice even proved harmful...

Even so, 'we do not know where we want vitamin D to be,' said Rebecca Jackson, professor of medicine at Ohio State University and an expert in vitamin D and bone health. 'We do not know what is an optimal level of vitamin D for good health.'...

And at least one major study has contradicted the overheated claims of vitamin D advocates. In 2006, new results from the Women's Health Initiative, a huge federal study launched in the 1990s that focused on the benefits and risks of hormones for postmenopausal women, showed little benefit in participants who were given extra calcium and vitamin D. The supplements had no effect on colon cancer rates, cardiovascular disease, invasive breast cancer, and, most surprisingly, no effect on overall bone fractures (though it did strengthen hip bones), researchers found.

'We didn’t even show a blip,' said Jean Wactawski-Wende, Ph.D., associate chair of the department of social and preventive medicine at the State University of New York at Buffalo and lead author of the study that looked at colorectal cancer rates in the Women’s Health Initiative participants.

So, the argument continues. All sides do agree on one thing: more research is needed...

Because there is no consensus on an optimal level of vitamin D, there is also no consensus on what most vitamin D tests really mean. There are also questions about the accuracy of some tests. For example, in January, Quest labs admitted inaccuracies in thousands of vitamin D deficiency tests...

Nobody is sure how to interpret deficiency results. Since genes influence how vitamin D is made and used, maybe one person’s deficiency is another person’s healthy. Perhaps there is a limit to how much vitamin D the body will process into the active hormone...

'I am believer, but also a pragmatist,' said Jackson. If somebody says ‘prove it, doc.’ I say ‘Eh, I can’t.’"

Good luck figuring out that one.