Calcium Isotopes in Juvenile Milk‐consumers

The calcium isotope ratios (δ 44/42 Ca) in milk‐consuming infants and juveniles are compared to adults at two archaeological sites to test whether milk consumption is detectable in the skeleton using calcium isotopes. At Aşıklı Höyük, δ 44/42 Ca is correlated with δ 15 N and differs significantly between juveniles and adults, suggesting that δ 44/42 Ca is responding to dietary milk input. However, at Christ Church, Spitalfields, no correlation between δ 44/42 Ca and δ 15 N or age is noted. At this site, δ 44/42 Ca of adult females is not related to the minimum number of births, and we conclude that the maternal skeleton is not sufficiently isotopically perturbed for this signal to remain throughout her lifetime. Growth may result in an increase in very young infants' δ 44/42 Ca, in contrast to an expected decrease due to milk consumption, complicating the interpretation of the data. We conclude that milk consumption does not always result in a change in skeletal δ 44/42 Ca, or is masked by other effects.