The controversy continues: Should the general population be screened for vitamin D deficiency? Should only patients known to be at risk be tested, and if so, which risk factors should be definitive? Experts have weighed in on all sides of the issue, and prestigious professional organizations have taken opposing positions. Meanwhile, as this month’s Product Focus indicates, prominent manufacturers are introducing assays to measure levels of the sunshine vitamin to the clinical laboratory market. Several interesting news releases have crossed my desk during the past few months. Here are a few, edited for space.
Vitamin D deficiency common in patients with lung disease
A new study from Korea has uncovered a high prevalence of vitamin D deficiency in individuals with chronic obstructive pulmonary disease (COPD), as well as a significant relationship between vitamin D deficiency and airflow limitations. Exercise capacity also tended to be decreased in participants with vitamin D deficiency.
Vitamin D may keep low-grade prostate cancer from becoming aggressive
Taking vitamin D supplements could slow or even reverse the progression of less aggressive, or low-grade, prostate tumors, without the need for surgery or radiation. In cases of low-grade prostate cancer, many urologists do not treat the disease, but instead do what’s called “active surveillance,” says Bruce Hollis, PhD. “The cure—surgery or radiation—is probably worse than the disease, so they wait a year and then do another biopsy to see where the patient stands.”
However, knowing that they have even low-grade prostate cancer can cause patients excessive anxiety, which prompts some men to undergo an elective prostatectomy, despite the risk of complications. But a man must wait 60 days from the time of his biopsy before he can undergo a prostatectomy, so that inflammation from the biopsy can subside.
Hollis wondered if giving these men vitamin D supplements during the 60-day waiting period would affect their prostate cancer. His previous research had shown that when men with low-grade prostate cancer took vitamin D supplements for a year, 55 percent of them showed decreased Gleason scores or even complete disappearance of their tumors compared to their biopsies a year before.
Vitamin D prevents diabetes and clogged arteries
In recent years, a deficiency of vitamin D has been linked to type 2 diabetes and heart disease. Both disorders are rooted in chronic inflammation, which leads to insulin resistance and the buildup of artery-clogging plaque.
Now, new research in mice at Washington University School of Medicine in St. Louis suggests vitamin D plays a major role in preventing the inflammation that leads to type 2 diabetes and atherosclerosis. Further, the way key immune cells behave without adequate vitamin D may provide scientists with new therapeutic targets for patients with those disorders.
Studying mice that lacked the ability to process vitamin D in immune cells involved in inflammation, the researchers found that the animals made excess glucose, became resistant to insulin action and accumulated plaques in their blood vessels.
“The finding that vitamin D helps regulate glucose metabolism may explain previous epidemiological studies identifying an increased risk of diabetes in patients with vitamin D deficiency,” said senior investigator Carlos Bernal-Mizrachi, MD, associate professor of medicine and of cell biology and physiology. “In our study, inactivation of the vitamin D receptor induced diabetes and atherosclerosis, so normalizing vitamin D levels may have the opposite effects.”
Vitamin D may help prevent and treat diseases associated with aging
Vitamin D may play a vital role in the prevention and treatment of diseases associated with aging, according to researchers at Loyola University Chicago Marcella Niehoff School of Nursing (MNSON). Researchers reviewed evidence that suggests an association between vitamin D deficiency and chronic diseases associated with aging such as cognitive decline, depression, osteoporosis, cardiovascular disease, high blood pressure, Type 2 diabetes and cancer.
“Vitamin D deficiency is a common, serious medical condition that significantly affects the health and well-being of older adults,” said study co-author Sue Penckofer, PhD.
“Better understanding the relationship between vitamin D and chronic diseases in older adults and whether treatment of vitamin D deficiency can prevent or treat these disorders is important given the increasing number of people at risk for these health issues,” said co-author Meghan Meehan, MN, FNP.
The Institute of Medicine generally recommends that adults up to 70 years of age take 600 IU of vitamin D daily and adults over the age of 70 consume 800 IU of the nutrient daily.
Vitamin D deficiency, depression linked in international study
Vitamin D deficiency is not just harmful to physical health; it also might impact mental health, according to a team of researchers that has found a link between seasonal affective disorder, or SAD, and a lack of sunlight. “Rather than being one of many factors, vitamin D could have a regulative role in the development of SAD,” said Alan Stewart of the University of Georgia College of Education.
Vitamin D is also involved in the synthesis of serotonin and dopamine within the brain, both chemicals linked to depression, according to the researchers.
“Evidence exists that low levels of dopamine and serotonin are linked to depression, therefore it is logical that there may be a relationship between low levels of vitamin D and depressive symptoms,” said the researchers.
Vitamin D deficiency increases poor brain function after cardiac arrest
Vitamin D deficiency increases the risk of poor brain function after sudden cardiac arrest by seven-fold, according to research conducted by Dr. Jin Wi of Yonsei University in Seoul, Korea. Vitamin D deficiency also led to a higher chance of dying after sudden cardiac arrest.
Wi said: “In patients resuscitated after sudden cardiac arrest, recovery of neurological function is very important. Vitamin D deficiency has been reported to be related to the risk of having various cardiovascular diseases, including sudden cardiac arrest. We investigated the association of vitamin D deficiency with neurologic outcome after sudden cardiac arrest, a topic on which there is no information so far.”
The researchers prospectively analyzed clinical data from all unconscious patients resuscitated from sudden cardiac arrest of presumed cardiac cause at Severance Cardiovascular Hospital in Seoul. Neurologic outcome was assessed by the Cerebral Performance Category (CPC) score at 6 months after discharge. Good neurologic outcome was defined as a CPC score of 1 or 2, whereas poor neurological outcome was defined as a CPC score of 3 to 5. Vitamin D deficiency was defined as 25-hydroxyvitamin D less than 10 ng/mL.
Patients with a poor neurological outcome had a significantly lower vitamin D level (7.9 ng/mL) compared to those with a good neurological outcome (12.4 ng/mL). The researchers found that 65% of patients with vitamin D deficiency had a poor neurological outcome at 6 months after discharge compared to 23% of patients with healthy vitamin D levels. They also found that 29% of patients with vitamin D deficiency had died at 6 months compared to none of the patients with good vitamin D levels (p= 0.007).
MLO has compiled a number of product items for testing Vitamin D below.
