Old teeth lack ‘D’

Teeth from four French women and two Quebec residents who died hundreds of years ago show the telltale signs of vitamin D deficiency, a new study says.

Lori D’Ortenzio, a PhD candidate in anthropology at McMaster University in Hamilton, came up with the idea to use teeth to detect vitamin D deficiency though people in her field usually deal with bones.

Unlike bones, teeth store a permanent record of microscopic abnormalities in layers of dentin, beneath the enamel, akin to the rings of a tree that begin to develop before birth, said D’Ortenzio, who led the study.

Researchers analyzed a total of 12 teeth from four women who were buried in a French cemetery between 1225 and 1798 and two people who were buried in rural Quebec between 1771 and 1860, a child believed to be three years old and a 24-year-old man.

An examination of three of the man’s teeth showed he’d suffered four bouts of rickets before he turned 13, D’Ortenzio said.

“We correlated the age at which the tooth was forming, with the location of the defect in the tooth. For example, if it was under the crown, it was earlier in the formation of that tooth, if it was in the root it would have been a little bit later.”

The researchers found that all the subjects had vitamin D deficiency, or rickets, which is a weakening of the bones caused by an extreme lack of the vitamin.

Their findings were published Tuesday in the Journal of Archaeological Science.

“We thin-sectioned the teeth and low and behold, there were these defects in the teeth,” said D’Ortenzio, describing the severe cases as resembling bubbles.

Researchers also had access to some of their subjects’ bones, which showed deformities.