Heterogeneity in experiences of vitamin D deficiency in an early to mid-19th century population from Montreal, Quebec

Objective: To use the prevalence of prenatal/infancy interglobular dentine (IGD) as a proxy for suboptimal vitamin D status and explore its link to mortality, biological sex, cultural behaviours and environmental factors during the end of the pre-industrial/ beginning of the industrial period.

Materials: 50 skeletons from the St. Antoine cemetery (1799-1854), Montreal, Quebec with a well-preserved first mandibular molar.

Methods: Thin sections were prepared for histological examination of IGD in crown dentine.

Results: IGD prevalence was 74 % (37/50) and not significantly correlated statistically to sex and age-at-death. Most IGD occurred at birth and up to 3 years-old, six individuals were affected in utero, 54 % of the sample (27/50) presented longstanding IGD and six individuals displayed multiple IGD episodes.

Conclusions: Prenatal IGD episodes revealed suboptimal maternal vitamin D levels, which, alongside a high frequency of IGD episodes around birth/from birth until a certain age, suggest cultural influences. Multiple and longstanding IGD episodes might also reflect suboptimal seasonal vitamin D attainment.

Significance: This study provides in-depth data on IGD within a relatively large archaeological North American sample, proving relevant to epidemiological studies on suboptimal vitamin status in 19th century Montreal.

Limitations: The total number of IGD episodes is underestimated due to methodological biases; first-generation migrants in this study could not be identified and excluded from the sample.

Suggestions for further research: Use of a larger sample with a wider age-at-death range; further research on infants and children to investigate links between growth and lesion formation and visibility.