During infancy, non-adults are highly susceptible to infectious diseases and deficiencies especially because of their immature immune system and their high demand for calories and nutrients due to their high growth rate. This partly explains the high mortality rate before the development of modern medical knowledge. It is well known in bioarchaeology through the osteological paradox that the absence of pathological bone lesions does not necessarily mean that a child died under healthy conditions and that the cause of the death is the disease diagnosed from the identified bonelesions. For this paper, we focused on the 109 infants (52 females, 57 males) aged 0-3 years from the collection of identified skeletons curated at the University of Bologna (Italy). Most of them died between 1900 and 1909 with a registered cause of death. These infants were meticulously observed for bone signs of deficiency diseases. 49.5% of the infants observed had at least one bone sign that could be associated with a deficiency, but less that 4% of them were recorded as having died of a metabolic disease. On the contrary most of the individuals with signs of deficiency died of infection, especially intestinal infection, mainly in an acute form. Deficiency diseases, even if not lethal – until a certain point –, result in the dysfunction of one or several metabolic cycles that can impact the immune system and maximize the risk of infection. A high prevalence of deficiency diseases in archeological populations could be considered an indicator of a high mortality from acute infection. Preservation of valuable osteological collections such as those from identified skeletons is essential to better understand the biases associated with the osteological paradox.< Réduire