Sun-bathers in hot places soak up soaring levels of vitamin D, but winter in the Midwest isn't so generous.
Most people need to take fairly high amounts of vitamin D supplement to gain the vitamin's health benefits, a Creighton University researcher says.
Dr. Robert Heaney co-authored a paper published last month in the journal “Anticancer Research” stating that people typically need hefty doses of vitamin D supplement to reduce the risk of cancer and other diseases.
The finding differs from an Institute of Medicine recommendation last fall that a comparatively small supplement would suffice. The institute serves as an adviser to the federal government on health and science policy.
Heaney, a longtime Creighton physician, researcher and administrator, conducted the study with a University of California San Diego researcher and GrassrootsHealth, an organization that promotes the use of vitamin D.
The Creighton scientist said it's hardly an explosive finding. “It's not controversial among working vitamin D scientists,” he said.
The study set out to show how much vitamin D supplement needs to be taken to produce levels in the bloodstream that help reduce the risk of diseases. Both Heaney and Dr. Cedric Garland, the California researcher, suggested in interviews that people start at 2,000 international units per day of vitamin D supplement.
They recommended that a person then have a physician test the level in his blood before deciding for the long term how much supplement to take. Garland said the amount of supplement taken by a person ultimately could rise to 4,000 international units per day or more, depending on the finding of the blood test.
Heaney said vitamin D has been shown by formal trials and “observational studies” to be effective in reducing the risk of bone deficiency, diabetes, breast and colon cancers, multiple sclerosis, certain pregnancy problems, and other diseases and difficulties.
It's not a magic bullet guaranteeing health, he said, but rather a nutrient that lowers disease risks over the long haul.
“It's cheap, it's easy and it could save us a bundle of money ... not to mention the personal cost of cancer,” he said.
The study, conducted from 2008 through 2010, involved 3,667 people, some of whom took high amounts of vitamin D supplement and some who took none. The researchers found it generally takes in the range of 1,000 to 3,000 international units or more to raise the vitamin level in the blood to a desirable level.
People also acquire varying amounts of vitamin D through sun exposure — the body manufactures it after being exposed to sunshine — and in vitamin-fortified milk, wild-caught salmon and other foods. Even with that, Heaney and Garland said high amounts of supplement are necessary. Both men said they take 3,000 international units a day.
Heaney said that's hardly a stunning dose. A person who sun bathes for 15 minutes in midsummer typically would acquire 15,000 international units, he said.
Garland said about 90 percent of Americans aren't getting enough vitamin D. He said it will take a while for the public at large to realize the importance of the vitamin.
“I can't think of any rational reason based on science that would point anyone in another direction,” Garland said. “I'm optimistic about it, but it hasn't happened yet, for sure.”
The Institute of Medicine last fall recommended that people take no more than 600 international units of the vitamin supplement.
“We haven't reviewed this particular study, so we're not in a position to comment on it,” an IOM spokeswoman said of Heaney's and Garland's latest finding. The spokeswoman, Christine Stencel, said it's not clear what long-term effects high doses of vitamin D supplements might have.
A Harvard-based study will examine the impact that taking 2,000 units might have. “So it's still emerging,” Stencel said of the science surrounding vitamin D.
Heaney said people in Europe have taken high doses of vitamin D with positive results and without adverse effects.
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