Vitamin D sales soar as studies link a deficiency to a host of conditions

"We're really where we were in the 1970s and 1980s with cholesterol," lead author Jeffrey L. Anderson said. Large clinical trials first proved that cholesterol-lowering drugs could reduce risk of death in the mid-1990s.

While the University of Utah School of Medicine cardiologist believes that more study is needed, he draws on his own knowledge of Vitamin D when seeing patients.

"I personally advise them to take it at the moment because I think that it is safe and it is good for other reasons for sure," he said. "I can't see that there is harm."

The Vitamin D Debate: How Much Do You Need?

Current supplement guidelines are not enough . . .

Every 100 IU of Vitamin D (the amount in one cup

of fortified milk) consumed daily raises the level of Vitamin D in the blood by about 1 ng/mL.

                   Federal guidelines vs.   Experts' advice

                                                 Wagner/

                        AI*      RDA*      Holick**    Hollis***

Birth to age 50          200    400        **

Pregnant women       200    400     1,400-2,000     4,000

Lactating women       200    400     2,000-6,000     6,000

Age 51 to 70             400    400     1,500-2,000**

Age 71 and older       600    600     1,500-2,000

Upper limit           2,000             10,000

* AI: "Adequate Intake" (minimum considered necessary). RDA: "Recommended Dietary Allowance" (simplified to apply to most people and translated on product labels as % of Daily Value). Both are based on Institute of Medicine reports.

** Michael F. Holick, Boston University School of Medicine, recommends 400-1,000 IU per day from birth to 1 year, 1,000-2,000 to age 12, and 1,500-2,000 for age 13 and over. He also recommends two to three times these amounts for obese people.

*** Carol L. Wagner and Bruce W. Hollis, Medical University of South Carolina.

. . . to raise Vitamin D to adequate levels            

Surveys show that at least half and up to 90 percent

of Americans have below-normal levels* of Vitamin D. There is no universal definition of "normal," although these are common.

In nanograms per milliliter (ng/mL):      

Mainstream medicine      vs.      Experts/holistic doctors

Very low     Low       Normal               Normal

Under 20    20-30   Over 30                40-80

* The level is determined by a blood test that a physician can order, and typically is covered by insurance. It costs between $50 and $250 without coverage.

SOURCES: Inquirer research