Recent research has reignited a debate over whether federal guidelines for vitamin D are outdated, possibly leaving millions vulnerable to health problems.

They call vitamin D the “Sunshine Vitamin” because it is created when sunlight hits your skin.

As a species, we continue to spend more time indoors, working, watching television and surfing the Internet, causing a drop in the amount of vitamin D our bodies create. In northern states, the angle of the sun gets so low, residents' bodies don’t make any.

Salmon, cod and other fatty fish are good sources of natural vitamin D. Food fortified with the vitamin, such as milk, orange juice and cereals, contain amounts based on old recommendations. For example, one 8-ounce glass of milk contains 100 international units, which is not enough, according to the American Medical Association.

This summer, the AMA called on the FDA to re-examine the current daily intake value established in 1997 by the National Academy of Sciences. Now, experts recommend at least 800 to 1,000 international units.

Dr. John Whitcomb, of Aurora Sinai Medical Center, believes that number is conservative.

“We have good published literature that 10,000 units a day forever is safe,” Whitcomb said.

Studies have also found vitamin D could possibly protect against heart disease, breast cancer, colon cancer, auto-immune disorders like rheumatoid arthritis, infectious diseases such as the flu and even mental illnesses, including schizophrenia and depression.

Harvard’s Men’s Health Journal came out this week stating that vitamin D is one of nine inventions that can save your life.

There are skeptics, but the number of experts agreeing with Whitcomb is growing fast.

“Every single person ... should say, 'I need a strategy for the six months of winter ... of supplementing myself with Vitamin D,'” Dr. John Whitcomb, of Aurora Sinai Medical Center said. “I believe it is the No. 1 public health advance in medicine in the last 20 years.”

Patient Ginny Boettcher said she was living with pain mostly across her shoulders, back and arms.

“I would pack myself with ice twice a day so that I could go back to work. I mean, it was a horrible way to live -- horrible,” Boettcher said.

Boettcher’s suffering was so severe, she thought she might lose the floral business she runs out of her Muskego, Wis., home. She said simply slicing a rose stem was difficult.

Not falling into a specific diagnosis, Boettcher said she was treated with a myriad of injections, pain medication, anti-inflammatory and deep tissue therapy.

“Who do I go to now? What do I do? Who do I talk to? What kind of doctor should I see because I've had no luck?,” Boettcher said she wondered when nothing worked.

A friend then asked her if she was taking vitamin D.

“I said, 'Oh yeah, now and then,’” Boettcher said.

That friend convinced Boettcher to see Whitcomb, who immediately started her on vitamin D supplements. Just six weeks later, Boettcher has seen a dramatic changed.

“I have no pain in my arms -- no pain in my hands. I play piano again,” Boettcher said.

Stories like Boettchers’ are becoming much more common.

“I'm having people spontaneously calling me up and saying stories like Ginny's,” Whitcomb said.