When I was a teenager, I drove cross-country with my father and fell in love with Montana. I spent my entire junior year of high school trying to figure out how much an acre of land cost and how much I'd have to spend on barbed wire, fence posts and, most important of all, the sheep.

That's right, I was going to move to Montana to be a sheep tycoon.

Surprise! Didn't happen. But I am still bullish on sheep—not for love of the voluptuous landscapes of Montana, but because of my family's health.

Last winter, for the first time in my children's lives (Summer, age 8; Cassidy, age 4), we all went through the winter without getting sick.

Our secret: 2,000 IU of vitamin D per olive-oil drop in a tincture bottle. I wasn't shy, either: Sometimes they'd get two or three drops a day.

The sheep? Their sheared wool is the commercial source of vitamin D used in foods, drinks and supplements. The grease, or lanolin, from the wool is the source of 7-dehydrocholesterol, which is irradiated to produce good ol' D. For hard-core veg-heads, vegan-source D2 is derived from ergot mold. Of note, vitamin D3, or cholecalciferol, has been shown to be three times better in raising blood levels and keeping them raised compared to vitamin D2 (ergocalciferol).

Currently, the U.S. Institute of Medicine recommends people get 200 IU of  either type of vitamin D a day, 400 IU if you're older than age 50 and 600 IU if you're 70 or older. You could call me a mega-doser, but I will defy you. Theses daily recommended intakes are the bare minimum amount people need to stave off a deficiency disease state, such as rickets.

I've talked with Robert P. Heaney, MD, at Creighton University in Nebraska, who is a major vitamin D researcher. He was on the IOM panel, which, in 1996, upped the vitamin D recommendations for those older than 50 to 400 IU per day and for those older than 70 to 600 IU per day. The panel kept the 200 IU per day standard for everyone else. Heaney told me: "Everything we know today about vitamin D we've learned since 1997."

He said the upcoming revised IOM vitamin D recommendations—expected to be announced sometime this fall—should be 2,000 IU a day. I'm guessing the preternaturally weak-kneed (read: vitamin-averse, precautionary principled) IOM will fall back to a more conservative 1,000 IU. Even so, that's a 500 percent increase—nothing to sneeze at.

Vitamin D, however, has a role much greater than immunity. New research shows the vitamin "controls the expression of more than 900 different genes and their associated functions, and may play a role in the control of more than 20,000 genes," writes Barbara Wexler in Vitamin D (Woodland Publishing, 2009).

Published research in the last two years alone shows vitamin D builds strong bones, may help reduce incidence and severity of the flu, corrects insulin resistance, decreases pregnancy complications, positively affects the heart and brain, decreases depression and acts against at least 17 kinds of cancer.

There has been one negative study on vitamin D recently. The headlines read that the vitamin leads to more bone breaks (as a result of falls) among the elderly. Lost in the coverage was that researchers gave subjects a one-time injection (not oral dose) of 500,000 IU. Since current regs advise a mere 200 IU, I wouldn't be too concerned about the ultra-mega-super-injection-dose study. 

But while vitamin D's profile has risen sky-high, almost everybody is still deficient.

I'm here to change all that—and help you get your customers on board too. Prominently place vitamin D on your shelves. And talk to every customer about it. They'll be glad you did.