This study investigates the association between early-life exposure to residential green space and bone mineral density in young children. The research, conducted in Flanders, Belgium, followed 327 children from birth to age 4-6 years. The study found that higher exposure to residential green space was associated with increased bone mineral density and a lower risk of having low bone density in children. Specifically, an increase in total green space within a 500-meter radius was linked to a significant increase in bone mineral density, while an increase in total green space within a 1000-meter radius was associated with a reduced risk of low bone density. These findings suggest that early-life exposure to residential green space may play a crucial role in bone health during critical periods of growth and development, with potential long-term implications for bone strength and fracture risk. The study highlights the importance of green spaces in promoting healthy bone development in children, emphasizing the need for policies that support the conservation and expansion of residential green areas. The research used quantitative ultrasound measurements to assess bone mineral density and controlled for various factors, including age, sex, weight, height, ethnicity, and maternal education. The study's results contribute to the understanding of how environmental factors influence bone health and underscore the potential benefits of green spaces in promoting overall health and well-being in children.This study investigates the association between early-life exposure to residential green space and bone mineral density in young children. The research, conducted in Flanders, Belgium, followed 327 children from birth to age 4-6 years. The study found that higher exposure to residential green space was associated with increased bone mineral density and a lower risk of having low bone density in children. Specifically, an increase in total green space within a 500-meter radius was linked to a significant increase in bone mineral density, while an increase in total green space within a 1000-meter radius was associated with a reduced risk of low bone density. These findings suggest that early-life exposure to residential green space may play a crucial role in bone health during critical periods of growth and development, with potential long-term implications for bone strength and fracture risk. The study highlights the importance of green spaces in promoting healthy bone development in children, emphasizing the need for policies that support the conservation and expansion of residential green areas. The research used quantitative ultrasound measurements to assess bone mineral density and controlled for various factors, including age, sex, weight, height, ethnicity, and maternal education. The study's results contribute to the understanding of how environmental factors influence bone health and underscore the potential benefits of green spaces in promoting overall health and well-being in children.