Taking care of teeth is a daily ritual – brushing, flossing and rinsing to ward off cavities.

But according to a new study led by Dr. Robert Schroth from the University of Manitoba, kids especially may need to do one more thing: take a vitamin D supplement.

The study found school-age children with optimal levels of vitamin D have a nearly 40 per cent lower risk of getting cavities.

"That vitamin D amount was absolutely significant between the two groups of kids without cavities and those with lots of them," said dentist Dr. Katie Davidson from the Cholakis Dental Group.

"It can encourage the body to produce its own natural proteins that will help protect the teeth."

Experts believe about 12 million Canadians don't have those optimal levels of vitamin D in their system. Add in long, overcast winters and those numbers rise to 14 million; which is why the study's authors recommend regular vitamin d supplements for children.