Vitamin D Wards Off Breast Cancer
Sunshine Vitamin May Reduce Risk for Pre-Menopausal Women
Recent studies suggest that increasing amounts of Vitamin D into daily life and diet may decrease the risk of breast cancer in pre-menopausal women.
Recently released results from a large-scale cohort study of nearly 40,000 women sponsored by the Women's Health Study suggest that women who get increased amounts of Vitamin D have a reduced risk of breast cancer, particularly for younger women. This finding has come up before, yet remains controversial because of the risk of skin cancer.
Higher levels of vitamin D translated to a 10-50 percent lower risk of breast cancer in pre-menopausal women, according to the study. Multiple studies, including a 16-year study sponsored by the Harvard School of Public Health and study by Saint George’s Hospital Medical School in London, have found increased amounts of vitamin D to diminish breast cancer risk in young women, though it has not shown a positive or negative change for post-menopausal women. Vitamin D boosts the immune system to prevent the formation of abnormal cells; however, research is too early to fully determine if higher levels can assist older women.
The wonder vitamin?
Vitamin D is vital to the body’s absorption of calcium. Vitamin D also promotes bone and teeth formation and mineralization, is essential in the development of a strong skeleton and healthy immune system, and helps with blood clotting.
Getting a high enough amount of vitamin D safely and effectively is difficult because the best way for the body to metabolize vitamin D is through sun exposure. Foods such as salmon, tuna, and fortified milk and cereals have high levels of the nutrient, but only low levels absorb into the body. Vitamin D supplements are also available, but also at a low absorption rate. In contrast, the body naturally produces vitamin D from sunlight because ultraviolet (UV) rays from the sun trigger the natural synthesis of vitamin D. This means the most efficient method to get vitamin D is through direct sun exposure.
At a cost?
So does a diminished risk of breast cancer have to come at the expense of an increased risk of skin cancer? Not necessarily, according to experts. For years doctors have advocated sunscreen and limited sun exposure, and these recommendations remain in effect. Ten minutes of unfiltered sunshine is adequate time to activate the body’s ability to start vitamin D synthesis, yet short enough not to be terribly harmful to the skin.
Beyond sun exposure, studies recommend increasing the amount of vitamin D intake through foods and supplements. The current FDA recommended intake is between 200-600 international units (IUs), but the studies find the effective level is likely to fall between 200 and 1,000 IU. However, in order to avoid an overdose of vitamin D, individuals need to be careful not to exceed 2,000 IUs daily in order to avoid a dangerous calcium buildup. Fortunately, since the average American consumes closer to 350 IUs daily, an overdose is unlikely.
Moderation is key
To reduce the health risks of UV radiation exposure, a combination of balanced diet, supplementation, and limited sun exposure is the best way to obtain vitamin D. Vitamin D supplementation is especially a consideration for individuals with limited sun exposure such as those living through New England winters and Northwest rain. If taking a Vitamin D supplement, do so under the direction of a physician to avoid medication conflicts, overdoses, or health problems.
For women with a genetic link to breast cancer, making dietary and lifestyle changes is one of the few things in their control to possibly decrease their risks. Therefore, these recent studies about the value of vitamin D – and how it is safe to get a higher amount – are sunny news.
Sources:
- WebMD Medical news
- Nutrition in Clinical Practice (2007: Vol. 22, No. 3, p. 305-322)
- American Cancer Society
