Frank C. Garland, the UC San Diego epidemiologist who, with his brother Cedric, was the first to demonstrate that vitamin D deficiencies play a role in cancer and other diseases, died Aug. 17 at UCSD Thornton Hospital. He was 60 and had been suffering for nearly a year from cancer of the esophageal junction.
"Over the past three decades, the Garlands' seminal hypothesis has been largely confirmed by numerous additional studies," Dr. Edward Giovannucci of the Harvard School of Public Health said in a statement. "Improving vitamin D status remains one of the most promising natural ways to combat incidence and death from some cancers."
The inspiration for their work came in July 1974 in a crowded seminar room at Johns Hopkins University during a slide presentation of maps of cancer mortality rates for the 3,056 U.S. counties. The Garlands were "startled," they later said, by maps showing that rates for breast and colon cancer mortality were twice as high in many northern counties compared with those in the southwest.
Researchers had no ready explanation for the finding, although some suggested that barbecuing, other foods, pollutants and a host of environmental factors might play a role. But perhaps because they had just driven from San Diego to the Baltimore meeting in their 1972 Mustang, the Garlands suspected that a beneficial effect of sunlight in the South was at the core of the differences.
They spent six years marshaling their evidence, then published their findings that vitamin D was capable of preventing cancer of the colon in 1980 in the International Journal of Epidemiology — a year before Frank Garland completed his doctorate. That publication defined his career path.
Their results contradicted conventional wisdom, which held that sunlight was, in Cedric Garland's words, "a dangerous cause of skin cancer and a peril to be avoided." While it is clear that too much sunlight can, indeed, cause melanoma, a certain amount is beneficial because it is necessary for the production of vitamin D.
In effect, they concluded that some forms of cancer could be better described as nutritional-deficiency diseases, much like scurvy and rickets.
Frank Garland then organized a 19-year historical cohort study in Chicago, correlating intake of vitamin D and calcium with colon cancer. He found that those in the top 20% of the population in terms of vitamin D intake had half the incidence of colon cancer as those in the bottom 20% of intake. This was the first study to show that taking vitamin D and calcium supplements could lower cancer risk.
In Garland's second major study, his team collected blood samples from 25,000 volunteers in Washington County, Md. The team found that people with the highest levels of the vitamin D metabolite 25-hydroxyvitamin D in their blood had only 20% of the normal risk of colon cancer.
Both papers were published in the medical journal Lancet and have since been cited in 95% of all other papers reporting vitamin D research.
In papers published in 1989 and 1990, Garland obtained similar results showing a link between vitamin D deficiency and breast cancer. Other researchers have shown links to heart disease, autoimmunity and depression.
As a result of the work of the Garlands and others, many public health agencies are beginning to recommend consuming larger amounts of vitamin D. Current U.S. guidelines recommend consuming 200 to 600 international units of vitamin D daily, but some researchers claim that boosting the dose to 2,000 IUs could prevent as many as 60,000 U.S. cancer deaths annually. Many researchers take even higher levels.
But some authorities, like the International Agency for Research on Cancer, recommend that clinical trials be conducted before recommending that everyone take high doses of the vitamin. Experts note that researchers had been overly enthusiastic about vitamin E and other supplements in the past, only to find that their expectations were not met when clinical trials were conducted.
Frank Caldwell Garland was born June 20, 1950, in San Diego. "From the time he was 3 or 4 years old, he had an intense interest in nature," his brother said. "His favorite expression was, 'I like observation and inference.' "
Garland's interest in California history led to a bachelor's degree in history from UCLA in 1972. Out of brotherly love for Cedric, who was already an epidemiologist at Johns Hopkins, he pursued a doctorate in epidemiology from the school, earning the degree in 1981.
He spent his entire career at UCSD but was also technical director of the Naval Health Research Center in San Diego.
Even later in life, "We would carry an atlas of cancer mortality as we drove across country," Cedric Garland said. "If a county had an unusually high or low incidence, we would tarry there longer and try to figure out why."
Garland remained single his entire life. "He had a lot of girlfriends and enjoyed life," Cedric said. "But he never married."
In addition to his brother Cedric, a professor of family and preventive medicine at UC San Diego, Garland is survived by his mother, Eva Caldwell Garagliano of San Diego.