Two new studies out of Germany add to an ever-growing body of evidence showing that optimal vitamin D levels are crucial for good health.
Based on the findings, people who are low or deficient in vitamin D are much more likely than others to develop cardiovascular disease, respiratory illness, and cancer, and are also more prone to dying early compared to those with optimal vitamin D levels.
In the first study, which was published in the American Journal of Clinical Nutrition (AJCN), researchers from the German Cancer Research Center (GCRC) conducted a population-based analysis of individuals between the ages of 50 and 74. During a followup period that lasted nearly 10 years, the team calculated the number of deaths that occurred from various conditions, as well as the number of respiratory and cardiovascular events.
They determined that the risk of all-cause mortality began to increase sharply among individuals with vitamin D levels lower than 75 nanomoles per liter (nmol/L) -- vitamin D levels are typically measured in terms of blood serum levels of 25-hydroxy vitamin D (25(OH)D). Individuals with 25(OH)D levels lower than 50 nmol/L but higher than 30 nmol/L were found to be about 17 percent more likely to die early, while those with levels below 30 nmol/L were about 71 percent likely to die early.
"In this large cohort study, serum 25(OH)D concentrations were inversely associated with all-cause and cause-specific mortality," wrote the authors. "In particular, vitamin D deficiency [25(OH)D concentration less than 30 nmol/L] was strongly associated with mortality from all causes, cardiovascular diseases, cancer, and respiratory diseases."
Similar conclusions were drawn from the second study, which was also conducted at GCRC. Nearly 10,000 men and women aged 50 to 74 living in Saarland, Germany, were included as part of the study, which was published in the journal Cancer Epidemiology, Biomarkers & Prevention. An eight-year follow period revealed that low vitamin D levels among primarily men was associated with an increased risk of prostate, lung, colorectal, and other types of cancer.
"25(OH)D concentrations were significantly associated with overall cancer incidence in subgroups of this large cohort from Germany," wrote the authors in their conclusion.
Your 25(OH)D levels should be higher than 125 nmol/L
According to the world-renowned Vitamin D Council, even 75 nmol/L of 25(OH)D is considered low, with an optimal range falling between 125-200 nmol/L (or 50-80 nanograms per milliliter). The Vitamin D Council offers an in-home vitamin D testing kit made by ZRT Laboratory that can help you determine whether or not you are lacking or deficient in vitamin D.
"Studies indicate that for proper health, serum vitamin D levels should be a minimum of 50 ng/mL (125 nmol/L), with optimal levels falling between 50-80 ng/mL (125-200 nmol/L)," writes the Council. "These values apply to both children and adults."