A new study from Trinity College Dublin scientists sheds light on the complexities of achieving optimal vitamin D status across diverse populations. Despite substantial research on the determinants of vitamin D, levels of vitamin D deficiency remain high. The study was recently published in the journal Clinical Nutrition.
The authors analysed data from half a million participants from the UK, and for each person, they calculated the individualised estimate of ambient ultraviolet-B (UVB) level, which is the wavelength of sunlight that induces vitamin D synthesis in the skin.
A comprehensive analysis of key determinants of vitamin D and their interactions revealed novel insights. The first key insight is that ambient UVB emerges as a critical predictor of vitamin D status, even in a place like the UK, which receives relatively little sunlight.
The secondis that age, sex, body mass index (BMI), cholesterol level, and vitamin D supplementation significantly influence how individuals respond to UVB. For example, as BMI and age increase, the amount of vitamin D produced in response to UVB decreases.
The research team believe that their findings are largely generalisable for Ireland, with both populations (Irish vs British) quite similar biologically/genetically, as well as other conditions — most notably the level of UVB light, but also other lifestyle factors, such as diet.
Dr Margaret M Brennan, Research Assistant, Department of Public Health and Primary Care, School of Medicine, Trinity College Dublin andfirst author, said: “We hope this work can highlight the significant differences in vitamin D levels among different ethnic groups at northern latitudes and contribute to efforts to address the long-standing population health issue of vitamin D deficiency.”
Prof Lina Zgaga, Associate Professor of Epidemiology, Department of Public Health and Primary Care, School of Medicine, Trinity College, and the principal investigator, said: “We believe our findings have significant implications for the development of tailored recommendations for vitamin D supplementation. Our study underscores the need to move away from a one-size-fits-all approach towards personalised strategies for optimizing vitamin D status.”
You can access the full paper, Ambient ultraviolet-B radiation, supplements and other factors interact to impact vitamin D status differently depending on ethnicity: a cross-sectional study, at www.clinicalnutritionjournal.com/article/S0261-5614(24)00113-4/fulltext.
