Migration from regions with strong sunshine to regions with low sunshine is linked to vitamin D deficiency.

A new study in the Oxford Economic Papers notes that the migratory flows of the last 500 years from regions with high sunshine to regions with low sunshine influence contemporary health outcomes in destination countries.

Researchers noted here that people’s ability to synthesize vitamin D from sunlight decreases with skin pigmentation, and that vitamin D deficiency is directly associated with a higher risk of death, disease. such as cardiovascular disease, type 1 and type 2 diabetes, hypertension, and some cancers. . Recent research has even revealed that vitamin D affects the severity of COVID-19.

The researchers here focused on clusters of high-sunshine regions that migrated to low-sun regions between 1500 and today. The resulting population changes dramatically increased the risk of vitamin D deficiency. Researchers explored the overall health consequences of such migration from a long historical perspective.

The researchers built here a measure that assesses the risk of vitamin D deficiency in a given population. The measurement tracked the difference between the intensity of sunlight in the ancestral place of residence of the population, as well as the actual level of intensity of sunlight at the current place of residence.

Using the difference between ancestors and ambient sunlight as a measure of the potential risk for vitamin D deficiency, the researchers then looked at its explanatory power in relation to life expectancy around the world. Researchers have found that an increased risk of vitamin D deficiency is negatively correlated with life expectancy, all other things being equal.

Researchers here noted that today there is widespread awareness of the harmful effects of excessive sun exposure, leading people to try to prevent sunburn through methods such as sunscreen and limited exposure outdoors. Effective treatments for skin cancer are also widely available. People also spend more time indoors than their prehistoric ancestors, which reduces their exposure to the sun. Therefore, the risk of premature death from excessive exposure to the sun has decreased since prehistoric times.

However, shorter exposure times to the sun increase the risk of vitamin D deficiency, especially in people with higher skin pigmentation, whose ancestors came from areas with strong sunshine.

Ultimately, the researchers concluded here that a migration-induced imbalance between the intensity of skin pigmentation and ambient sunlight can both connect and explain the differences in current global health: regions low sunshine which have received substantial immigration from high sunshine regions have a lower life expectancy than would have been the case in the absence of such migratory flows.

“This research is important because it is the first research to document a link between an increased risk of vitamin D deficiency and differences in life expectancy between countries and regions. It thus serves to highlight the potentially huge benefit in terms of extra years of life from taking vitamin D supplements, especially during the fall and winter, ”said author Dr. Thomas Barnebeck Andersen.