Scientific evidence of vitamin D's vast benefits is building ( Part 1 )

Want to build sturdy bones and strong muscles? Prevent cancer? Dodge the flu in all its forms? An increasing number of health care professionals, including some very vocal and visible ones, say a single supplement can help you do all that and more — and a growing body of research supports their contention.
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That wonder substance that works wonders? Vitamin D — of which studies have estimated 1 billion people worldwide are deficient.

"It's clear that vitamin D is different from the other vitamins," said Dr. Rick Klamm, a family practitioner with ThedaCare Physicians-Neenah East. "It's really a hormone. It's not a vitamin."

Familiar as an additive in milk, vitamin D is unique in that we don't need to get it from a food source. Rather, our skin manufactures it upon exposure to the sun. That's part of the reason why, especially at northern latitudes like ours, the "D" in vitamin D could stand for deficient.

"In Wisconsin from October to April, we really can't make vitamin D, even if we do go out in the sun," said Dr. Roxanne Jadin-Cardelli, an internist with Aurora Health Center in Neenah.

In light of such geographical fluctuations, some scientists suspect that vitamin D helps defend against several conditions more prevalent in less sun-infused climates. Here, we consider a few of them.

An immunity booster

On the recommendation of her health care provider, Jeri Barry, 47, of Neenah takes 4,000 IUs, or International Units, of vitamin D each day. She also just finished a high-dose regimen after a blood test found her vitamin D level insufficient — that is, below about 30 nanograms per milliliter.

"I had 12 weeks when I took 50,000 IUs once a week to get my level to where my doctor thought it should be," Barry said.

She didn't do so without digging a little deeper first. "My question, of course, was, 'My gosh, that sounds like a ridiculous amount to be taking. What are the down sides?'"

There are few if any, according to Klamm, who along with his wife takes 2,000 IUs of vitamin D daily. He advocates vitamin D supplementation as one weapon in warding off the flu, which spikes in various geographic regions precisely when sunlight levels plummet.
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"There are vitamin D receptors on the body's immune cells," he said. His perspective: "They're there for some reason."
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Added Cardelli, "There is evidence also that our white blood cells are more effective at killing germs if our vitamin D level is higher."

To Barry's dosage concern, Klamm would respond in much the same way Barry's own health care provider did: The balance between the risks and benefits of vitamin D supplementation leans pronouncedly to the side of benefits.

"It's almost impossible with over-the-counter vitamin D to get too much," Cardelli said.

For those wanting to take action to prevent flu this fall and winter, Klamm said, "vaccinating is a good idea, washing hands is a good idea and taking vitamin D is a good idea. It's easy, and it's cheap."

A cancer preventive

Scientists further speculate that vitamin D plays a role in fending off cancer, particularly of the colon and breast. Two factors enter into their suspicion.

First, these diseases occur more frequently further from the equator, where more people are deficient in vitamin D.

"(Scientists) noted that there's a correlation between where you live on the planet and risk for certain diseases," Cardelli said.

Second, like immune cells, the tissues affected by several cancers have vitamin D receptors. Klamm said again, "If you either believe in evolution or the good Lord, there's a reason for them being there."

While the mechanisms of vitamin D's cancer-fighting effects are not yet understood or proven, every month sees new scientific articles published on the topic, said Dave Hall, Ph.D., associate professor of chemistry at Lawrence University in Appleton.

"There's a lack of vitamin D, and now researchers are going in and asking the questions," Hall said.

Answering them is a long and involved process.

"You have to do a prevention study, which takes a long time and a lot of people," Cardelli said.

"It's extremely difficult to examine nutrients and look at health effects," Hall said. "We hear a lot of different things about, 'Well, you don't have enough vitamin E in your diet,' or vitamin C, and there are a lot of conflicting studies."
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With vitamin D, he added, "You still have these same problems, but the data is pretty clear that vitamin D is providing a benefit. The evidence is gathering more steam."
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A bone builder

Because it's critical in the absorption of calcium, vitamin D long has been recognized as important in building strong bones. Said Klamm, historically, vitamin D deficiency was associated with rickets, a softening of bones in children.

While few children are diagnosed with rickets these days, many are nonetheless low in vitamin D.

"It's pretty clear that somewhere in the neighborhood of half of all people under the age of 18 don't get enough vitamin D," Hall said.

The problem exists even among nursing infants.

"We used to think breast milk was the ideal food," Klamm said. "It turns out there's not much vitamin D in breast milk."

Though bone-building seems most critical for the young, it's just as if not more important for the old, whose skin makes vitamin D far less efficiently. At age 20, spending 20 unprotected minutes in the sun twice a week is all it takes for you body to manufacture sufficient vitamin D, Cardelli said; by age 70, the number climbs to 80 minutes.

Klamm said studies in nursing homes have proven that vitamin D supplementation is helpful in improving both bone and muscle strength. He added that some elite athletes now train at altitude near the equator for similar reasons: They believe that the extra vitamin D their skin creates in such a setting boosts performance.

Though the jury's still out on vitamin D's conclusive capabilities, plenty of people are taking it in the meantime.

"You never know because it's never the only thing going on with you. All I know is it didn't hurt me at all, and I haven't even had a cold in 2½ years," Barry said.

to be continued.........



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