UV light exposure vs vitamin D supplementation: a comparison of health benefits and vitamin D metabolism in a pig model

In a 4-week study using pigs as models, researchers compared the effects of endogenously produced vitamin D through UV exposure and orally ingested vitamin D on vitamin D metabolism and health. The UV-exposed pigs exhibited higher vitamin D3 levels in various tissues, increased plasma concentrations of certain metabolites, and altered gene expression related to vitamin D metabolism compared to the orally supplemented group. Notably, UV exposure was associated with lower hepatic cholesterol, higher plasma nitrite levels, and a reduced inflammatory response in peripheral blood mononuclear cells. Despite these differences, no distinct variations were found in plasma metabolome or stool microbiome analyses. The findings suggest that different strategies for improving vitamin D status may impact vitamin D metabolism, blood pressure factors, and immune response, shedding light on potential explanations for varied health effects observed in association and intervention studies.