In one of our February 2010 newsletters, I shared a research study that predicted the reduction of 100,000 cases of breast and colon cancer annually in the US as well as a 75% reduction of cancer deaths, with adequate vitamin D levels. As more research studies continue to be reported, I am becoming increasingly impressed by its health giving abilities. Also, I see a vast improvement in my family and friends, after they begin to take it.
Once again, the same distinguished group of researchers has made an assessment of the global impact appropriate vitamin D levels would have on cancer reduction and prevention. Please note, their estimate doesn’t include a reduction of other chronic diseases linked to vitamin D deficiency including heart disease, depression, hypertension, arthritis, asthma, multiple sclerosis and others.
Dr. Cedric F. Garland, cancer prevention specialist at the Moores Cancer Center, University of California, San Diego (UCSD) and colleagues estimate that 250,000 cases of colorectal cancer and 350,000 cases of breast cancer could be prevented worldwide by increasing intake of vitamin D3, particularly in countries north of the equator.
A total of 600,000 cases a year of breast and colorectal cancer could be prevented each year by adequate intake of vitamin D3.
“For the first time, we are saying that 600,000 cases of breast and colorectal cancer could be prevented each year worldwide, including nearly 150,000 in the United States alone,” according to Dr. Garland. The paper, which looks at the dose-response relationship between vitamin D and cancer, will be published in the journal Nutrition Reviews.
The study collected information from surveys of serum vitamin D levels during winter from 15 countries. It is the first such study to look at satellite measurements of sunshine and cloud cover in countries where actual blood serum levels of vitamin D3 had also been determined. The data were then applied to 177 countries to estimate the average serum level of a vitamin D metabolite of people living there.
The results indicated an inverse relationship between vitamin D with risk of colorectal and breast cancer. Meaning lower levels had a greater risk for developing these cancers.
The protective effect began at levels ranging from 24 to 32 ng/ml of 25-hydroxyvitamin D concentration in the serum. The 25-hydroxyvitamin D level is the main indicator of vitamin D status. The late winter average 25-hydroxyvitamin D in the US is about 15-18 ng/ml.
The researchers believe raising vitamin D levels in populations, especially those in northern climates, has the potential to both prevent and possibly serve as an adjunct to existing treatments for cancer.
The work builds on previous studies by Garland and colleagues published in the Journal of Steroid Biochemistry and Molecular, February 2007) which found that raising the serum 25(OH)D levels to 55 ng/mL was optimal for cancer prevention. This is the initial research to recommend optimal vitamin D serum levels which, Dr. Garland said, are high enough to provide the needed benefit but which have been found by other scientists to be low enough to avoid health risks.
“This could be best achieved with a combination of diet, supplements and short intervals – 10 or 15 minutes a day – in the sun,” said Garland. It could be less for very fair-skinned individuals. He went on to say that “the appropriate dose of vitamin D in order to reach this level, could be very little in a lifeguard in Southern California… or quite a lot for someone in Northern Europe who tends to remain indoors most of the year.”
The level recommended by the study correlates with taking 2000 IU per day of vitamin D3 for a meaningful reduction in colorectal cancer. The researchers recommend 2000 IU/day, plus, when weather allows, a few minutes in the sun with at least 40% of the skin exposed, for a meaningful reduction in breast cancer incidence, unless the individual has a history of skin cancer or a photosensitivity disease.
Garland also recommends moderate sun exposure and use of clothing and a hat when in the sun longer than 15 minutes.
Previous studies from this core group have shown an association between higher levels of vitamin D3 or markers of vitamin D status and lower risk of cancers of the breast, colon, ovary and kidney. The researchers underscore their call for prompt public health action to increase intake of vitamin D3 as an inexpensive tool for prevention of diseases that claim nearly one million lives each year globally.
“The message is, depending on where you live, you may need to consider taking in considerably higher levels of vitamin D3 than those currently recommended,” said Garland. “I’d recommend discussing vitamin D needs with a health care professional, who may order and interpret a simple blood test for a vitamin D metabolite [25(OH)D], and provide a dosage recommendation that’s appropriate for the individual’s needs.”