Researchers at McMaster University have found a new record of vitamin D deficiency - one that resides in the teeth of every person and remains viable for hundreds of years or more.
The team of anthropologists has determined that looking into the microscopic structure of teeth opens a window into the lives and challenges of people who lived hundreds of years ago, and whose only record is their skeletal remains. Their paper, published online in the Journal of Archaeological Science, establishes that when the body is deprived of vitamin D, permanent microscopic abnormalities form in the layers of dentin - the tooth structure under the enamel - creating an ongoing record that can later be read like the rings of a tree.
The layers store what happens as teeth grow, says author Lori DOrtenzio, a PhD candidate in Anthropology at McMaster. We all know the importance of vitamin D, but until now we did not have such a clear way of measuring exactly what happened to people, and when.
The discovery is significant, since it can yield valuable information about vitamin D deficiency also known as rickets which continues to be a serious public health issue, affecting some 1 billion people worldwide. Most cases of rickets are caused by a lack of sun exposure, with effects that can include pain, bone deformities and failure to achieve or maintain adequate bone levels.
If we can properly understand past changes in deficiency levels, we can evaluate where we currently are and move forward, says author Megan Brickley, a professor of Anthropology at McMaster who holds the Canada Research Chair in the Bioarchaeology of Human Disease.
Until now, scientists trying to understand historical patterns in vitamin D deficiency have had to use bones, which are problematic sources of such information. In life, bone material is constantly being remodeled, obscuring details of prior damage. After death, bones interact with soil and break down.
Dentin And Dental Enamel
Dentin is not remodeled, and dental enamel much harder than bone protects the dentin long after death, making teeth a rich and accurate source of archaeological information. Theyre essentially fossils in your mouth, says author Bonnie Kahlon, a lab coordinator in McMasters Department of Anthropology.
The researchers compared the teeth of modern-day control subjects to teeth extracted from bodies buried in rural Quebec and France in the 1700s and 1800s. Their analysis showed that one Quebec man had suffered four bouts of rickets in his 24 years of life all before he turned 13.