Babies born to women with low levels of vitamin D during pregnancy may be at increased risk for tooth enamel defects and early childhood tooth decay, a Canadian study finds.

Researchers at the University of Manitoba analysed the vitamin D levels of 206 women in their second trimester of pregnancy and found only 21 (10.5 per cent) of the women had adequate vitamin D levels. The women's levels of vitamin D were related to the frequency of milk consumption and prenatal vitamin use.

The researchers also examined 135 infants and found that 21.6 per cent of them had enamel defects and 33.6 per cent had early childhood tooth decay. Mothers of infants with enamel defects had lower, but not significantly different, mean vitamin D concentrations during pregnancy than mothers of infants without enamel defects.

Mothers of infants with early childhood tooth decay had significantly lower vitamin D levels than mothers of cavity-free infants.