Vitamin D deficiency and pregnancy in early medieval Milan: study of two cases from the Ad Martyres and San Vittore al Corpo necropolises

The emergency excavations of the Ad Martyres and San Vittore al Corpo urban cemeteries since 2018 have unearthed 319 and 92 tombs respectively, dated from the Roman era to the Late Middle Ages. In the early medieval phases of both sites, representing 98 and 22 tombs respectively, three individuals showed signs of vitamin D deficiency: of these, two women had skeletal deformities attributable to osteomalacia including scoliosis, reduced rib-neck angle, coxa vara, severe bending of the pelvic bones, protrusio acetabuli, and narrowed pelvic outlet. The metabolic condition and skeletal deformities must have affected the quality of life of these women, causing bone pain, muscle weakness, fatigue, increased risk of morbidity, gait alteration, difficult and limited mobility, and abnormal compression of internal organs from deformations of the pelvic girdle and scoliotic curvatures with alteration of breathing patterns. In addition, each woman was associated with a fetus of about 25-36 gestational weeks: one was found in situ within the pelvic cavity and the other, unrecorded by the archaeologists, was recovered in the soil of the tomb associated with the skeleton. Under the mother-infant nexus framework, previous and existing maternal life course experiences – here vitamin D deficiency, aggravated from the current pregnancy – must have impacted upon the health of the growing fetus, though not visibly macroscopically. Given the severe biomechanical abnormalities displayed in the skeletons of these women and the advanced development of both fetuses, it is probable that both the mothers and fetuses died due to childbirth complications.