Vitamin D Deficiency and Cancer
New and exciting scientific research indicates that vitamin D may help to prevent cancer as well as other chronic diseases. Many of us have wrongly assumed that our vitamin D levels are adequate since we drink milk, are exposed to the sun, and take a multivitamin. However, it is now known that even with these activities, most people have a vitamin D deficiency. This deficiency may play a role in causing serious illness such as heart disease, hypertension, and other diseases, but in particular, cancer. The following is information from current research on vitamin D and its association with cancer.
What is the Association between Vitamin D and cancer?
While vitamin D is essential for bone formation, growth and repair, new research studies suggest that it is also associated with a reduced risk of breast, prostrate, and colorectal cancer. These studies, showing a possible cancer-protective role, were performed in laboratory experiments on cancer cells in culture, and in randomized clinical trials. Several studies have shown the following effects on cancer.
Prostate cancer- cells contain receptors for the active form of vitamin D and respond to vitamin D (3) with decreases in cell growth, invasiveness and metastasis, and increases in cell death.
Breast cancer Cedric Garland at the University of California in San Diego, and other prominent researchers, in a study involving more than 120,000 women determined that women with vitamin D levels above 52 ng/ml have half the risk of developing breast cancer as those with 13 ng/ml. The researchers estimate that 58,000 new cases of breast cancer in the United States could be prevented per year by raising levels to 52 ng/ml.
Colorectal cancer- A new study using meta-analysis, a sophisticated analytical technique, examined the data from five previous observational studies. The study examined the effect of vitamin D on colorectal cancer risk, with a follow-up of 25 years. Results showed that increased serum levels up to 34 ng/ml reduced the incidence rates of colorectal cancer by half. Rates were reduced even further with higher serum levels.
What is vitamin D and where do we get it?
Vitamin D is not an actual vitamin, but an inactive fat soluble pre-hormone (inactive precursor to a hormone). It helps the body absorb and regulate calcium and phosphorus. There are two major forms, D(2) (ergocalciferol) and D(3) (Cholecalciferol). D(2) is made by plants while D(3) is made by the body, via exposure to ultraviolent radiation (UVB-radiation) from the sun. The body modifies both forms in the liver to an active form (Calcitriol) and then further modifies it in the kidneys to 1, 25-dihydrovitamin D, the form used by the body.
We also get vitamin D from our diet from fatty fish, fish liver oil and eggs as well as from fortified foods such as milk juice yogurt, bread and cereal. However, both the D(2) and D(3) forms are commercially available as dietary supplements.
What is the Right amount of Vitamin D to take?
This question is not an easy one to answer. The answer depends on many personal factors. The amount needed varies with age, body weight, percent body fat, season of the year, skin color, latitude, lactation, amount of sun exposure and the use of sun-block. It is suggested that those who are not exposed to the sun as often should take more.
The recommended serum levels are now 50 ng/ml. However, in regards to how much to take, it is best to consult with your health care provider to discuss testing for vitamin D levels in the blood and increasing your vitamin D intake.