Bit­ing re­search: Teeth pro­vide clues into vi­ta­min D’s roots

The Hamilton Spectator - - LOCAL - MARK MCNEIL mm­c­neil@thes­pec.com 905-526-4687 | @Markatthes­pec

an­thro­pol­o­gist Me­gan Brick­ley isn’t a den­tist but she does know how to dig some in­ter­est­ing in­for­ma­tion out of teeth.

Brick­ley is part of a group of McMaster Univer­sity re­searchers, work­ing with col­leagues in Que­bec and France, who have de­vel­oped a new way to de­ter­mine vi­ta­min D de­fi­cien­cies from the den­tine of an­cient chom­pers.

Den­tine is the ma­te­rial that forms the bulk of the tooth, and the method­ol­ogy de­vel­oped by the re­searchers can be used on teeth spec­i­mens hun­dreds of thou­sands of years old to get a sense of sun ex­po­sure ex­pe­ri­enced when the per­son lived.

It means a new di­ag­nos­tic tool is avail­able to sci­en­tists to ex­am­ine count­less teeth sam­ples kept in mu­se­ums around the world.

The tech­nique makes use of the fact that new lay­ers of den­tine can­not min­er­al­ize if the per­son has suf­fered se­vere vi­ta­min D de­fi­ciency, a dis­or­der known as rick­ets. So lay­ers can be ex­am­ined to see lev­els of ex­po­sure to sun­light.

From this, re­searchers can gain in­sight into the adap­ta­tion by early hu­mans who moved from equa­to­rial Africa into re­gions that had less sun­light.

The den­tine can be used to bet­ter un­der­stand skin pig­men­ta­tion that was tak­ing place to me­tab­o­lize more sun­light.

“An­thro­pol­o­gists can get answers about some fairly im­por tant ques­tions such as changes in skin pig­men­ta­tion and also ques­tions about what is re­ally hap­pen­ing in terms of chang­ing lev­els of de­fi­ciency in so­ci­eties,” said Brick­ley, who is known in Hamil­ton for her work ex­am­in­ing the re­mains of sol­diers from the Bat­tle of Stoney Creek.

You’d think early hu­mans would have been ex­posed to sun all the time, and you wouldn’t ex­pect to find vi­ta­min D de­fi­ciency with them — es­pe­cially com­pared to hu­mans who live in western so­ci­eties to­day.

But Brick­ley says “hu­mans are com­plex crea­tures and there is a range of so­cial and cul­tural rea­sons why that might not hap­pen.”

For ex­am­ple, she said, some­one with a higher so­cioe­co­nomic sta­tus who lived long ago might spend a lot of time in­doors and wear cloth­ing that shields from the sun.

HAMIL­TON SPEC­TA­TOR FILE PHOTO

Mac’s Me­gan Brick­ley is part of a team that de­vel­oped a new way to de­ter­mine vi­ta­min D de­fi­cien­cies.

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