Research studies conducted in the last 20 years reveal that vitamin D deficiency is extremely prevalent and has been linked with a variety of health conditions, including cancer. Vitamin D is produced in the skin when exposed to the sun. Sun exposure is the main source of vitamin D, since diet alone offers very little amounts of this essential nutrient even in products thought to be high in Vitamin D, such as milk.
In a placebo controlled trial conducted between 2000 and 2005 on 1,179 healthy postmenopausal women, vitamin D supplementation showed a significant reduction in the risk of developing cancer. Specifically, there was a 60% decreased risk of cancer while taking 1,100 IU vitamin D along with calcium. Considering that some women may have had undiagnosed cancer at the beginning of the study, the scientists at Creighton University eliminated the first year of the study and analyzed only the following three years. The results found were even better, showing a whopping 77% percent cancer risk reduction! This study was featured in the 2007 issue of “Medical News Today.”
Breast cancer is the most common form of cancer in women and the role of vitamin D in breast cancer prevention or management has been demonstrated in numerous epidemiological and laboratory studies, including a large study involving 67,721 French women, as described in an article published in Medical News Today in 2012.
African American women also appear to be more deficient in this nutrient and have more aggressive forms of breast cancer. This fact is likely due to the fact that darker skin pigmentation acts somewhat as a block to producing vitamin D when exposed to sunlight.
Two out of three cancer patients are vitamin D deficient. The lower the blood levels of 25-hydroxy-vitamin D, the more advanced is the cancer, is the conclusion of a study presented in 2011 at the 53rd Annual Meeting of the American Society for Radiation Oncology (ASTRO). The five most common primary diagnoses associated with vitamin D deficiency were breast, prostate, lung, thyroid and colorectal cancers. In this research study, 77% of cancer patients had vitamin D concentrations either deficient (less than 20 ng/mL) or sub-optimal (20-30 ng/mL), with a median serum vitamin D level of 23.5 ng/mL.
The daily dose of vitamin D should be re-evaluated as soon as possible, because the current doses of 400-800 IU of vitamin D a day will not offer a reduction of risk of breast and colon cancer, as well as multiple sclerosis or type 1 diabetes, according to researchers for UC San Diego Moores Cancer Center.
Rather than considering a standard dose for all adults, a blood test should be done and vitamin D blood levels should be 40 to 60 ng/ml. Doses up to 1000 UI are considered safe, because this amount of vitamin D is produced in the skin when exposed to the sun for roughly 30 minutes. National Academy of Sciences Institute of Medicine suggests doses between 4,000 and 10,000 IU daily of either type of vitamin D for cancer prevention.
