After her yearly checkup with her doctor, Mary Wesley was surprised to learn the results of her blood work: She had a vitamin D deficiency.

"I was telling them I was tired, and it turns out my vitamin D was very, very low," recalled Wesley, who lives on Charleston's West Side and goes to the FamilyCare Community Health Center. "They said I wasn't getting enough sun, that I wasn't outside enough."

A recent study found a striking difference in the numbers of black adults who have vitamin D deficiency compared to whites - even after controlling for factors such as sun exposure and diet.

The Southern Community Cohort Study found that 45 percent of blacks had a vitamin D deficiency, compared to 11 percent of whites.

The study - Wesley is one of 75,000 people taking part - is designed to investigate cancer among blacks and low-income adults between the ages 40 and 79 in 12 Southern states. Vitamin D might help prevent some cancers, according to recent research.

"African-Americans have some of the highest rates of vitamin D deficiency simply because their skin is darker," said Lisa Signorello, co-principal investigator for the project. "There's a wide disparity, and that disparity held even in a region of high sunlight exposure."

A person's full requirement of vitamin D can be obtained from exposure to the sun - sometimes as little as 10 to 15 minutes a day. However, people with deeply pigmented skin require 10 times the exposure of fair-skinned people to produce the same amount of vitamin D, according to the researchers.

Wesley and about 1,500 other FamilyCare patients are taking part in the study. Adult patients from community clinics in Martinsburg and Huntington also are participating.

Research shows vitamin D deficiency might contribute to several cancers, including colorectal and breast cancer, as well as other chronic diseases.

"It's a hot topic right now," said Signorello, who works with the International Epidemiology Institute in Rockville, Md., and Vanderbilt-Ingram Cancer Center in

Nashville, Tenn. "People are wondering whether a lack of vitamin D is responsible for high rates of cancer. We're still in the early stages of understanding how vitamin D is preventing disease and what level of intake we should be having."

After her yearly checkup with her doctor, Mary Wesley was surprised to learn the results of her blood work: She had a vitamin D deficiency.

"I was telling them I was tired, and it turns out my vitamin D was very, very low," recalled Wesley, who lives on Charleston's West Side and goes to the FamilyCare Community Health Center. "They said I wasn't getting enough sun, that I wasn't outside enough."

A recent study found a striking difference in the numbers of black adults who have vitamin D deficiency compared to whites - even after controlling for factors such as sun exposure and diet.

The Southern Community Cohort Study found that 45 percent of blacks had a vitamin D deficiency, compared to 11 percent of whites.

The study - Wesley is one of 75,000 people taking part - is designed to investigate cancer among blacks and low-income adults between the ages 40 and 79 in 12 Southern states. Vitamin D might help prevent some cancers, according to recent research.

"African-Americans have some of the highest rates of vitamin D deficiency simply because their skin is darker," said Lisa Signorello, co-principal investigator for the project. "There's a wide disparity, and that disparity held even in a region of high sunlight exposure."

A person's full requirement of vitamin D can be obtained from exposure to the sun - sometimes as little as 10 to 15 minutes a day. However, people with deeply pigmented skin require 10 times the exposure of fair-skinned people to produce the same amount of vitamin D, according to the researchers.

Wesley and about 1,500 other FamilyCare patients are taking part in the study. Adult patients from community clinics in Martinsburg and Huntington also are participating.

Research shows vitamin D deficiency might contribute to several cancers, including colorectal and breast cancer, as well as other chronic diseases.

"It's a hot topic right now," said Signorello, who works with the International Epidemiology Institute in Rockville, Md., and Vanderbilt-Ingram Cancer Center in

Nashville, Tenn. "People are wondering whether a lack of vitamin D is responsible for high rates of cancer. We're still in the early stages of understanding how vitamin D is preventing disease and what level of intake we should be having."

Signorello's study - published this month in the journal Cancer Causes & Control - also found that many blacks weren't getting enough vitamin D, even though they were eating right and meeting recommended dietary guidelines. Tuna, milk, eggs and fortified cereals are rich in vitamin D.

"Most of it comes from sunlight," Signorello said, "not what you put in your mouth."

Signorello said people who want to know whether they're getting a sufficient amount of vitamin D should ask their doctor to add vitamin D to the list of things checked during a blood test.

Scientists now are debating the pros and cons of sunscreens, Signorello noted. Too much could block vitamin D absorption. Not enough could lead to some skin cancers.

Vitamin D deficiency also can lead to bone-softening diseases, such as rickets.

FamilyCare Director Martha Carter said the Southern Cohort study notifies participants of research findings, prompting patients to ask questions and take better care of themselves. Carter also enrolled in the study, which required answering questions during an hourlong interview and giving blood and urine specimens.

"I wanted to know firsthand that participants were cared for with respect all the way through the study," Carter said.

Wesley, a case manager for the nonprofit Hope Community Development Corp. in Charleston, said she worries about cancer because her mother died of breast cancer at age 50. After talking with her doctor, Wesley increased her intake of vitamin D. She said she feels a lot better now.

"I make it a point now to sit in the sun on my deck and roast a little bit, take a vitamin D supplement, and eat a little more cheese," Wesley said. "The study was great. A lot of people who had a problem didn't realize it."

Reach Eric Eyre at erice...@wvgazette.com or 348-4869.