It’s no secret that teeth are important tools for humans and animals alike. They allow us to eat, help us speak, and make for a handy weapon in a pinch. In many cases, teeth have even been used to make jewelry, much like the oldest jewelry ever discovered, 100,000-year old beads made from Nassarius shells. But researchers have recently discovered a new use for teeth: determining the nutritional deficiencies of ancient humans.
Researchers from McMaster University in Canada have developed a new method to study imperfections in teeth, specifically those caused by a lack of sunlight. As it turns out, humanity’s long relationship with the sun and vitamin D has been locked inside our teeth the whole time, just under the surface.
Megan Brickley, lead author of the paper and Canada Research Chair in the Bioarchaeology of Human Disease, explained that her research has opened up new opportunities to learn about ancient humans.
“This is exciting because we now have a proven resource that could finally bring definitive answers to fundamental questions about the early movements and conditions of human populations — and new information about the importance of vitamin D for modern populations,” Brickley told Science Daily.
The bulk of Brickley and her team’s research involved dentine, a material that makes up the majority of a tooth. In 2016, researchers established that this material carries a permanent record of vitamin D deficiency. During periods of severe deficiency, new layers of dentine can’t form. This leaves microscopic evidence that the researchers can read. The process has been likened to reading rings on a tree.
Until now, there has been no definitive or reliable method of tracking vitamin D deficiency. Today, about 15 million people in the U.S. have replacements for missing teeth, but until recently it was extremely common for people to have multiple missing teeth. Now, ancient teeth offer more clues about early man’s way of life.
Brickley’s new research is proof that vitamin D deficiency is hardly a modern issue. In fact, the earliest evidence of vitamin D deficiency in this study was from the late Pleistocene era, in four out of five teeth recovered from Mount Carmel in Israel.
Researchers even compared ancient teeth to modern teeth, providing valuable evidence that could help medical professionals understand a health issue that affects an estimated 1 billion people in the world today. When 26% of Americans report spending 9 to 12 hours in their home, out of direct sunlight, every day, it’s enough to create a concern about vitamin D levels.
Future research on this subject may prove extremely useful not just to oral health, but to the health of humanity in general.