Gender-related vitamin D deficiency in a Dutch 19th century farming community.

The most common cause of vitamin D deficiency is inadequate dermal exposure to sunlight. Residual rickets is nonadult vitamin D deficiency still evident in an adult individual, whereas osteomalacia occurs in adulthood. Previous research on the Beemster population, a 19th century rural community in the Netherlands, identified rickets in 30.4% of the nonadults between the ages of two and four years (n=7/23). Because the sex of these nonadults was not known it was not possible to determine if there were differences between boys and girls. To overcome this gap in our knowledge, the aim of this paper is to determine if there are gender related differences in vitamin D deficiency in the Beemster skeletal collection, based on adults with residual rickets and osteomalacia. Out of 200 adults (100 females; 100 males) no cases of osteomalacia were detected. However, there were 29 cases of residual rickets (14.5%), with 21 of those cases in females (21.0%; 21/100). A complex interplay of multiple factors is proposed to have affected vitamin D levels in nonadults, including sociocultural variables such as gender-based labour norms. This research highlights the importance of continuing to explore gender-based health differences in past populations.