Historical teeth reveal how volcanic activity caused vitamin D deficiencies

Researchers from Durham University analyzed teeth from a centuries-old cemetery in northeast England to study how climate shocks contributed to childhood diseases.

The team examined 30 teeth from 21 unidentified individuals buried at Coach Lane between 1711 and 1829. By looking at mineralisation failures in the tooth dentin, the scientists sought to understand why many children suffered from rickets, a condition where the skeleton fails to harden properly due to a lack of vitamin D.

The study suggests that while industrial pollution and poor housing played a role in vitamin D deficiency during the Industrial Revolution, natural climate events also had a major impact. The researchers found that the period coincided with the Little Ice Age, a cooling era caused by low solar activity and volcanic eruptions. These events released aerosols into the atmosphere that blocked sunlight, reducing the amount of UVB light available for the body to produce vitamin D.

Data from the cemetery's burial register showed that 91 out of 109 people with known birth years were born during or within 10 years of a large volcanic eruption. The researchers believe that cold, wet summers likely kept children indoors and wrapped in heavy clothing, further limiting skin exposure to sunlight.

While the study does not claim climate was the sole cause of these health issues, it argues that natural climate variability has been overlooked in favor of focusing only on human-caused industrialization.