In the City’s Shadow:
How a Lack of Sunlight Led to Rickets in Roman Children
by Collin Ponader
An analysis of skeletal remains recovered from Roman burial sites reveal that as many as one in twenty Roman children showed signs of vitamin D deficiency attributed to increasing urban development, a fact that has worrying implications for people in today’s cities.
KEYWORDS: Bioarchaeology, disease, Roman Empire, urbanism
In the 1st to 6th century AD, an insidious disease wormed its way into Roman cities, leaving behind a legacy of crippled children, their bones twisted and malformed, hidden away in the dimly lit residences common at the time. Affecting over one in twenty children across the Roman Empire, rickets is a condition which cause children to have soft, weak bones, and can lead to bowed legs and stunted growth.
Rickets is usually caused by a lack of vitamin D, which helps growing bones maintain proper levels of minerals such as calcium. Most commonly, the culprit is a lack of exposure to sunlight, a necessary ingredient for the vitamin. Those living in densely populated, polluted urban centers are at particular risk.
Previously, rickets was thought of by scientists as a Victorian disease, suggesting that it arose primarily during the 19th century as a result of the industrial revolution and its sprawling, crowded cities. However, as new bioarchaeological research indicates, rickets is as ancient as the development of cities.
Taking note of this connection between cities and rickets, a team of researchers led by skeletal biologist Simon Mays looked to the first period of widespread urban development: the Roman Empire. Mays and his team examined 2,787 skeletons from 18 different cemeteries ranging from the 1st to 6th centuries AD, looking for any signs of the skeletal deformities associated with rickets. Shockingly, they found signs of rickets in more than one in twenty children, most of them infants.
Mays and his team postulate that the cause of the disease was simple: mothers were keeping their children indoors where they lacked exposure to sunlight and its crucial supply of vitamin D, a lack that would eventually prove fatal as the disease compromised their immune system and stunted growth. Unsurprisingly, the researchers found more evidence of rickets in England than elsewhere in the Empire, where the cloudy skies and rainy climate could have contributed to a lack of sun exposure.
Another area with a high occurrence of the disease was Ostia, one of Rome’s major ports on the Tiber river. The reason? According to Dr. Christopher Gregg, associate professor of art history, classical art and archaeology at George Mason University, “the concentration and frequency of apartment buildings in cities like Ostia means that the density would be greater than other ancient cities,” a fact that would have “important consequences” for Ostia’s inhabitants. Living amidst these dense, multi-story apartment blocks and narrow streets might have meant that children weren’t exposed to enough sunlight to prevent vitamin D deficiency, a discovery that has worrying implications for the more than 55 percent of the world’s population who currently live in similar conditions in modern cities.
The findings of this research, published in the American Journal of Physical
Anthropology, teach an important lesson to modern society. The United Nations estimates that two-thirds of the world population will live in cities by 2050.With an estimated 1 billion people already affected by vitamin D deficiency, if care isn’t taken to ensure proper exposure to sunlight in children this “19th century affliction” could make the jump to the 21st.
S. Mays, T. Prowse, M. George, M. Brickley. (2018) Latitude, urbanization, age, and sex as risk factors for vitamin D deficiency disease in the Roman Empire. American Journal of Physical Anthropology 167:484–496.