February 24, 2012
Current Vitamin D Levels Found In Millions of People Are Allowing Chronic Inflammation
Researchers have discovered specific molecular signaling events by which vitamin D prevents inflammation. In their experiments, they showed that low levels of Vitamin D, comparable to levels found in millions of people, failed to inhibit the inflammatory cascade--a series of rapid biochemical events which propagates and matures the inflammatory response. However, levels considered adequate did inhibit inflammatory signaling. They reported their results in the March 1, 2011, issue of The Journal of Immunology.
“This study goes beyond previous associations of vitamin D with various health outcomes. It outlines a clear chain of cellular events, from the binding of DNA, through a specific signaling pathway, to the reduction of proteins known to trigger inflammation,” said lead author Elena Goleva, assistant professor of pediatrics at National Jewish Health. “Patients with chronic inflammatory diseases, such as asthma, arthritis and prostate cancer, who are vitamin D deficient, may benefit from vitamin D supplementation to get their serum vitamin D levels above 30 nanograms/milliliter.”
Pale populations have multiplied and have migrated across the earth, many times to geographic regions which are to their disadvantage. Researchers have noted that sunlight and supplements are not the only factors that can determine the level of vitamin D in a person's body.
Lighter skin color allows deeper penetration by UV-B rays, which decreases the amount of sunlight exposure needed for adequate vitamin D production. If you have darker skin, it's harder for UV-B rays to penetrate your skin and create vitamin D, which means that you need greater exposure to sunlight than someone with lighter skin.
Some inherited differences in the way people's bodies process vitamin D into the active form also have a strong effect on people's vitamin D levels.
Current national guidelines suggest that people should maintain a minimum blood serum level of 20 ng/ml, although there is much scientific debate about optimum level. Many experts are now suggesting that the guidelines be doubled and even tripled to 60 ng/ml to prevent disease. Vitamin D has long been known to contribute to bone health by promoting the absorption of calcium. In recent years, much attention has been paid to its possible immune and inflammatory benefits. Low vitamin D levels have been associated with several diseases including asthma, cancer, diabetes, and arthritis.
In the current study researchers examined the specific mechanisms by which vitamin D might act on immune and inflammatory pathways. They incubated human white blood cells with varying levels of vitamin D, then exposed them to lipopolysaccharide (LPS), a molecule associated with bacterial cell walls that is known to promote intense inflammatory responses.
Cells incubated with no vitamin D and in solution containing 15 ng/ml of vitamin D produced high levels of cytokines IL-6 and TNF-alpha, major actors in the inflammatory response. Cells incubated in 30 ng/ml vitamin D and above showed significantly reduced response to the LPS. The highest levels of inflammatory inhibition occurred at 50 ng/ml.
Researchers at the Heart Institute at Intermountain Medical Center in Salt Lake City followed 27,686 patients who were 50 years of age or older with no prior history of cardiovascular disease and found that patients with very low levels of Vitamin D were 77 percent more likely to die, 45 percent more likely to develop coronary artery disease, and 78 percent were more likely to have a stroke than patients with normal levels. Patients with very low levels of Vitamin D were also twice as likely to develop heart failure than those with normal Vitamin D levels.
Vitamin D refers to two biologically inactive precursors - D3, also known as cholecalciferol, and D2, also known as ergocalciferol. The former, produced in the skin on exposure to UVB radiation (290 to 320 nm), is said to be more bioactive.
While our bodies do manufacture vitamin D on exposure to sunshine, the levels in some northern countries are so weak during the winter months that our body makes no vitamin D at all, meaning that dietary supplements and fortified foods are seen by many as the best way to boost intakes of vitamin D.
William Grant and Dr. Mercola
discuss Vitamin D and Cancer Link Part 1
William Grant and Dr. Mercola
discuss Vitamin D and Cancer Link Part 2