A first-of-its-kind study of vitamin D levels among those whose outdoor lifestyles give us the best clues of what is natural for humans supports the contention that regular tanners have natural vitamin D levels and non-tanners are falling far short.

Published in the British Journal of Nutrition this month by Dr. Martine F. Luxwolda and a group of colleagues from The Netherlands, the study looked at Vitamin D blood levels in those who live natural outdoor lifestyles.

“People with traditional lifestyles, living in the cradle of mankind, have a mean circulating 25(OH)D concentration of 115 nmol/l (46 ng/ml),” the group wrote. “Evolutionary medicine tells us that our genes have been selected in an environment in which we successfully exploited hunting and gathering strategies for survival and procreation. Since the agricultural (about 10,000 years ago) and industrial (100–200 years ago) revolutions, we have, however, drastically changed our conditions of existence and continue to do so with still increasing pace. These changes cause a conflict with our slowly adapting genome that basically still resides in the Paleolithic era.”

In other words, our body’s genes haven’t caught up to the recent phenomena of working indoors behind a desk.

“The ensuing lack of exposure to direct sunlight negatively affects our vitamin D status, and thereby adds to the current state of homeostatic imbalance,” the research team wrote. “Cutaneous synthesis of vitamin D by exposure to UVB is our principal source of vitamin D, which in reality is a pro-hormone with both rapid and slow effects and which also controls the expression of about 3 percent of our genes.”

And, as it turns out, the amount of vitamin D you need for that function of vitamin D is above 40 ng/ml, according to independent research – although Luxwolda and her colleagues shied away from making that conclusion, which they believe needs further research. The group did acknowledge that “the current low vitamin D status of populations living in affluent countries is implicated in many diseases that are related to the calcaemic and non-calcaemic functions of vitamin D, including rickets, osteomalacia, osteoporosis, CHD (hypertension), cancer (colorectal cancer, breast cancer and prostate cancer), infectious diseases (tuberculosis, influenza and HIV) and autoimmune diseases (type 1 diabetes, multiple sclerosis and rheumatoid arthritis).

The North American vitamin D average today is about 23 ng/ml. Indoor tanning clients average close to 46 ng/ml, according to the American Journal of Clinical Nutrition.

The world’s leading vitamin D researchers have embraced 40-60 ng/ml as the target range for everyone. (http://www.grassrootshealth.net/epidemic)

To review the new study from The Netherlands click here.