Vitamin D deficiency is a major cause of breast cancer among women, according to a recent study published in the American Journal of Clinical Nutrition. The study, authored by a team of scientists from various organizations, reports that women in Saudi Arabia who have low vitamin D levels have six times the risk of having breast cancer than women with higher levels. Researchers urge others to increase vitamin D intake for a myriad of life-saving health benefits.
The case-control study analyzed data from 120 breast cancer cases and an equal amount of controls. The study found that Saudi Arabian women in the lowest vitamin D category, less than 25 nmol/L (10 ng/ml), had six times the risk for evasive breast cancer as people in the highest category of vitamin D status, greater than 50 nmol/L (20 ng/ml). Women in Saudi Arabia, even though they reside in a high UV sunlight exposure area, have very low levels of vitamin D. This is due to a modern indoor lifestyle, darker skin types, cultural practices of dress and the fact that the food supply is not fortified with vitamin D like it is in Canada and the USA.
The data collected for the study indicated that breast cancer cases had significantly lower serum concentrations of 25-hydroxyvitamin D [25(OH)D], at an average of 9.4 ng/mL, than did controls, which averaged at 15.4 ng/mL.
“These results are not surprising” says Dr. Cedric Garland, a Professor from the UCSD Department of Family and Preventive Medicine. “There are numerous studies supporting that women need vitamin D levels exceeding the Institute of Medicine (IOM) guideline of 50 nmol/L (20 ng/ml) to help prevent breast cancer.
“Our study, published in the Annals of Epidemiology in July 2009, reported that raising women’s 25(OH)D blood serum level to 100-150 nmol/L (40-60 ng/ml) would prevent 58,000 new cases of breast cancer and three quarters of deaths from these diseases in the US and Canada.” added Dr. Garland. “We need help and support from the medical community especially family doctors to communicate this to their patients and put the vitamin D breast cancer prevention opportunity into daily practice to save lives.
“Optimal levels of vitamin D have the potential to drastically reduce breast cancer cases in Canada and the USA” said Perry Holman, Executive Director for the Vitamin D Society. “The Vitamin D Society recommend that people have their 25(OH)D level tested either through their family doctor or by purchasing a home test kit through health suppliers such as GrassrootsHealth. If your vitamin D test score is low, below 100 nmol/L Canada or 40 ng/ml USA, take immediate action to increase your vitamin D intake.
Arash Hossein-nezhad, MD, PhD, Michael F. Holick, PhD, MD of the Boston University Medical Center published an article, “Vitamin D for Health: A Global Perspective,” detailing the health benefits associated with vitamin D. Their article outlines how vitamin D deficiency continues to be a problem in today’s society and the risks associated with it. “Because body fat can sequester vitamin D, it is now recognized that children and adults who are obese require 2 to 5 times more vitamin D to treat and prevent vitamin D deficiency,” writes Hossein-nezhad and Holick, suggesting that America’s disturbing obesity rate may mean that a growing number of citizens are suffering from vitamin D deficiency, whether they realize it or not.
Vitamin D can be found naturally in very few foods. Wild salmon and mushrooms exposed to UV rays are two of the scarce natural food items containing vitamin D. Despite this, Hossein-nzhad and Holick’s article goes on to list other available sources of vitamin D and how to increase one’s uptake of the important nutrient:
“Vitamin D intake can be increased by eating foods fortified with vitamin D. A recent systematic review found that food fortification with vitamin D (especially in milk) is effective in significantly increasing 25(OH)D levels in the population.7, 252 Other foods include some cereals, juices, other dairy products, and some margarines. A mean individual intake of approximately 11 µg/d (440 IU/d) from fortified foods (range, 120-1000 IU/d) increased 25(OH)D concentrations by 7.7 ng/mL, corresponding to a 0.48-ng/mL increase in 25(OH)D for each 40 IU (1 µg) ingested.
Hossein-nzhad and Holick’s paper finishes with words of advice, urging readers to increase the amount of vitamin D they intake: “There is potentially a great upside (in terms of improving overall health and well-being) to increasing serum 25(OH)D levels above 30 ng/mL. An effective strategy to prevent vitamin D deficiency and insufficiency is to obtain some sensible sun exposure, ingest foods that contain vitamin D, and take a vitamin D supplement.