When a nasty flu struck California's Atascadero State Hospital, Doctor John Cannell made an interesting discovery.
"I know my patients had been exposed to influenza, but none of them got sick," he said.
Why? One reason could be that 30 of Cannell's patients had been given vitamin D on a regular basis. That got Cannell thinking more and more about the vitamin's benefits and safety.
"A child has never gotten into a vitamin D cabinet and gotten poisoned. That happened hundreds of thousands of times with Tylenol or aspirin or other things," Cannell said.
Medical writer Bill Sardi says that if vitamin D were a drug, its benefits would make it the most popular ever "because we're talking about diabetes and hypertension and bone diseases, osteoporosis, and arteriosclerosis and cancer and autoimmune disease and the list goes on."
Scientists found that list is so long because vitamin D actually regulates cells, systems, and organs throughout the body.
Cannell explained, "It works by turning your genes on and off -- a very basic function. So that's a very important fact about vitamin D that distinguishes it from any other vitamin. It's a steroid hormone, it's in a class by itself."
Vitamin D and Sun Exposure
A major question and area of controversy regarding vitamin D is sun exposure, so health investigators hit the trail looking for answers.
Doctors have observed that where there's less sun, there's more cancer, flu, and even autism. For instance, there are more of these diseases in winter, which has less sunlight. There are also more of these diseases the further you get from the equator, because the further you move away the less sunlight there is.
Even in sunny California very few people get enough sun to make sufficient vitamin D in their skin for the best of health.
"Down in San Diego you can make it year around. But even there in the winter time you have to go right out at solar noon," Cannell said. "There is only a two or three hour window where you're going to make any substantial amounts of vitamin D."
But wouldn't this possibly lead to skin cancer? Most sunscreen companies provide products that block the ultraviolet-B, or UVB, from the sun. Those are the very rays needed to produce vitamin D in the skin.
"Now they admit that the UVA rays that the sunblock lotions allow to get in are the ones causing the cancer. So they let the one that cause skin cancer in -- and they block the one that prevents it," said Bill Sardi of Knowledge of Health, Inc.
Statistics show skin cancer rates and deaths have actually risen since the sunscreen campaigns began thirty years ago.
Cannell recommends keeping your time in the sun moderate - 15 minutes in a bathing suit during summer is plenty. You don't want to age your skin or cause damage from sunburn. But not everyone agrees.
The American Academy of Dermatology Web site finds it "appalling" that "anyone in good conscience could make the claim that intentional sun exposure - for any length of time - is beneficial."
What about Those with Darker Skin?
Then there's the issue of darker skin -- which naturally screens out more of the UVB rays that make vitamin D. Their blood levels of vitamin D are about half that of lighter-skinned people, making a connection with the diseases that shorten their lives.
"Heart disease and hypertension and stroke and cancer are the same diseases that have been associated with vitamin D deficiency," Cannell said.
So it may not be surprising that vitamin D deficiency affects as much as three-quarters of the populace especially as winter takes its toll on vitamin D levels.
That depletion could be remedied and possibly reduce the need for flu shots.
"Vitamin D activates your immune system, causes something to be formed called little peptides, which kill bacteria and viruses without antibiotic resistance, without side effects. We can use it in very young infants and pregnant moms," Sardi said.
It will not only help fight osteoporosis, but strengthen teeth as well.
Sardi said, "Instead of using fluoride to harden our teeth so there's no soft spots where the acids can eat into our teeth and cause dental decay, we can use vitamin D. It's more appropriate, it's more natural."
"If you have diabetes and you take vitamin D and your blood sugar gets low, don't stop the vitamin D. Stop some of your diabetic medications, go talk to your doctor," Cannell said.
And vitamin D also appears to boost athletic performance.
"There's just clear evidence - especially in the German literature - of choice reaction time, balance, muscle strength, endurance -- all improve with vitamin D," Cannell said.
This may explain why senior citizens on vitamin D are less likely to fall and hurt themselves.
Vitamin D and Cancer
As for cancer, Sardi says in a new book that a major reason not to be so fearful about the disease is vitamin D. A key U.S. study in June found it provided a 60 percent reduction in cancers.
"The Canadian Cancer Society immediately told all their citizens to begin supplementing with at least 1,000 units of vitamin D. The American Cancer Society? Mum's the word," Sardi said.
But two weeks ago the National Cancer Institute released a study indicating vitamin D doesn't do much against cancer deaths.
NCI normally prefers the type of study done in June, but Cannell says this new study fits their bias against vitamin D. Even at that, the new study did show the vitamin's effect on the number two cancer killer.
"People with the highest levels had four times less colon cancer than the people with the lowest levels. I think that's pretty important," he said.
So, what is the best way to get the Vitamin D you need? Not from food. Even fortified milk provides so little that it's trivial. Taking supplements is a far more predictable source than sun bathing - and the only source in winter for millions.
Experts suggest the best daily intake is at least 2,000 units for most kids and 4,000 for most adults. Yet the government recommends only 200 to 600 units depending a person's age.
"This whole thing when you think about it is patently absurd. And the government has been recommending this for ten years. They refuse to change, they refuse to even look at the science," Cannell said.
He says he and his wife have taken as much as several hundred thousand units for a few days when fighting off colds or flu. His usual daily dose is 5,000 units -- a dozen times what the government recommends for him. He finds it a religious question.
He said, "Here, the Lord is saying there's a system that makes this much vitamin D this quickly -- thousands of units a day from sun exposure. And here's the government over here saying you only need a couple of hundred units a day. So you can sort of ask yourself, 'Who do you want to believe -- God or the government?'"