A string of recent discoveries about the multiple health benefits of vitamin D has renewed interest in this multi-purpose nutrient while increasing awareness of the huge numbers of people who are deficient in it. At the same time, new research of this essential vitamin has even led to an appreciation of it as “nature's antibiotic.”
On issues ranging from the health of your immune system to prevention of heart disease and even vulnerability to influenza, vitamin D is now seen as one of the most critical nutrients for overall health; but it's also one of those most likely to be deficient, especially during winter when the body's production of the “sunshine vitamin” almost grinds to a halt for millions of people in the United States, Europe and other northern temperate zones.
Variations of the vitamin are even being considered for use as new therapies against tuberculosis, AIDS, and other health concerns. As such, federal experts are now considering increasing the recommended daily intake of the vitamin as more evidence of its value emerges, especially for the elderly.
“About 70 percent of the U.S population has insufficient levels of vitamin D,” said Adrian Gombart, a principal investigator with the Linus Pauling Institute at Oregon State University. “This is a critical issue as we learn more about the many roles it may play in fighting infection, balancing your immune response, helping to address autoimmune problems, and even preventing heart disease.”
Vitamin D deficiencies were once believed to primarily affect bone health and cause rickets, but it's now understood that optimal levels of this nutrient influence much more than that.
The emerging health issues and key findings associated with global vitamin D research were outlined in a new report published in the journal Future Microbiology.
Scientists at OSU found that vitamin D induces the “expression” of cathelicidin, an antimicrobial peptide gene. This explains, in part, how it helps serve as the first line of defense in your immune response against minor wounds, cuts, and with bacterial and viral infections.
In the study, Gombart and colleagues found that higher levels of human cathelicidin antimicrobial protein (hCAP18), which are regulated by vitamin D, appear to significantly reduce the risk of death from infection in dialysis patients. Patients with a high level of this protein were 3.7 times more likely to survive kidney dialysis for a year without a fatal infection.
Experts believe advances in the use of cathelicidin may form the basis for new future therapies.
Another compelling new observational study completed by researchers at the Intermountain Medical Center in Utah, and presented Nov. 16, 2009, at a meeting of the American Heart Association, followed nearly 28,000 patients, ages 50 or older with no prior history of cardiovascular disease for more than a year. It found that in patients with very low levels of vitamin D – compared to those with normal levels – 77 percent were more likely to die, 45 percent were more likely to develop coronary artery disease, and 78 percent were more likely to have a stroke.
“We concluded that among patients 50 years of age or older, even a moderate deficiency of Vitamin D levels was associated with developing coronary artery disease, heart failure, stroke, and death," said Heidi May, PhD, MS, one of the study’s authors.
“This is important because Vitamin D deficiency is easily treated. If increasing levels of Vitamin D can decrease some risk associated with these cardiovascular diseases, it could have a significant public health impact," she said.
According to the new report, “Vitamin D insufficiency and deficiency is a global pandemic and a serious public health threat in both developed and developing nations. Nearly one billion people world-wide are deficient.”
Vitamin D can be obtained from the diet, often through supplemented foods such as milk, but those sources are rarely adequate, the experts say. Most people get the bulk of this fat-soluble vitamin from the UV-B radiation in sun exposure, which is naturally produced in the body. However, people with dark skin, infants and almost anyone living north of about 40 degrees latitude – which is a significant portion of the U.S. population and most of Europe– are often severely deficient after months of inadequate winter sunshine.
Other values and observations about vitamin D that are outlined in the new report included :
- Low levels of circulating vitamin D are associated with increased risk and mortality from cancer.
- Vitamin D plays an important role in activating the immune system, fostering the "innate" immune response and controlling over-reaction of adaptive immunity, and as such may help control autoimmune diseases such as multiple sclerosis, psoriasis and rheumatoid arthritis.
- The regulation of cathelicidin by vitamin D, a unique biological pathway for the function of vitamin D that could help explain its multiple roles in proper immune function, is so important that it's only known to exist in two groups of animals - humans and non-human primates - and has been conserved in them through millions of years of evolution.
- Vitamin D deficiency is a risk factor for tuberculosis, was historically used to treat it, and variations of the compound may provide the basis for new therapeutic approaches not only to that disease but also HIV infection.
- Epidemiological studies show a link between vitamin D deficiency and increased rates of respiratory infection and influenza, and it has been hypothesized that flu epidemics may be the result of vitamin D deficiency.
- Vitamin D has important roles in reducing inflammation, blood pressure and helping to protect against heart disease.
Sources: Gombart, A.; Bhan, I.; Borregaard, N.; Tamez, H.; Camargo Ca, J.; Koeffler, H.; Thadhani, R. (2009). “Low plasma level of cathelicidin antimicrobial peptide (hCAP18) predicts increased infectious disease mortality in patients undergoing hemodialysis”. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America 48 (4): 418–424. doi:10.1086/596314. PMID 19133797.
Gombart, A.F. “The Vitamin D—antimicrobial peptide pathway and it role in protection against infection”. Future Microbiology (2009) 4(9).www.futuremedicine.com
Lynette Summerill, is an award-winning journalist who lives in Scottsdale, Arizona. In addition to writing about cancer-related issues, she writes a blog, Nonsmoking Nation, which follows global tobacco news and events.