Vitamin D May Reduce Breast Cancer
by Dana Burnett
Vitamin D has been praised for its numerous health benefits, including cardiovascular, bone, and cellular health. A study presented at the San Antonio Breast Cancer Symposium examined the correlation between serum vitamin D levels and tumor size in patients with breast cancer. The study found that low vitamin D levels were linked to larger tumors.
Researchers reviewed data from 1,800 breast cancer patients treated between 2003 and 2010. Individuals that weren’t deficient in vitamin D had a lower incidence of the cancer returning, as those with low vitamin D levels (under 30 ng/mL) were more likely to have a relapse in three years. It is believed that the anti-inflammatory properties in vitamin D are able to mediate the effects on cancerous tumors.
Vitamin D 101
Vitamin D is a pre-hormone, meaning it has no hormone activity until it is converted by the liver and kidneys into the active steroid hormone 1,25-hydroxyvitamin D (Calcitrol). Vitamin D is typically created in the skin by UVB irradiation delivered from sunlight. Unfortunately, concerns about sun exposure, along with living in environments with minimal amounts of sunlight, can lead to deficient levels in the blood.
Vitamin D has two major forms, vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). The liver converts both forms into 25-hydroxyvitamin D (calcidiol), then the kidneys convert calcidiol into 1,25-hydroxyvitamin D (calcitrol – the active form used by the body). Both Vitamin D2 and D3 can be taken to reduce a deficiency, but D3 is more effective in sustaining vitamin D levels in the blood. Vitamin D2 is only 20 to 40% effective, because the body breaks it down too quickly.
Food
Small amounts of vitamin D can be found in salmon, cod liver oil, sardines, eggs, and yogurt. Food sources that contain 20% or more of the Daily Value of vitamin D are considered to be a substantial source.
Cod liver oil (340%)
Sockeye Salmon (199%)
Mackerel (97%)
Tuna Fish (39%)
Milk, vitamin D fortified (29-31%)
Orange Juice, vitamin D fortified (25%)
Yogurt, vitamin D fortified (20%)
Vitamin D Supplements
With many vitamin D deficiencies leading to widespread health ailments, it is important to make sure you are obtaining a good dose of this essential nutrient. The best source for vitamin D is through supplementation, as it can ensure you are receiving the adequate amount you need to be healthy. While vitamin D2 can help increase vitamin D serum levels, vitamin D3 more effectively raises low vitamin D levels.
For adequate assimilation, vitamin D3 should be taken with oil-containing meals or fish oil supplements. Calcium-Magnesium supplements can also be taken at the same time.
References
Hatse S, et al “Vitamin D status in newly diagnosed breast cancer patients inversely correlates with tumor size and moderately correlates with outcome” SABCS. 2011; Abstract P5-05-01.
Holick MF. Vitamin D deficiency. N Engl J Med. 2007; 357:266-281.
Holick MF. The vitamin D epidemic and its health consequences. J Nutr. 2005 Nov; 135(11):2739S-2748S.
Office of Dietary Supplements. Dietary Supplement Fact Sheet: Vitamin D. Retrieved on September 2, 2010from http://ods.od.nih.gov/factsheets/vitamind.asp#en10
