Previous investigation has suggested that nutritional factors could influence many aspects of inflammation. Vitamin D is a pro-hormone and essential micronutrient, and various types of immune cells express both the vitamin D receptor and metabolizing enzymes. This suggests that hormonal vitamin D might also play a role in modulating inflammatory responses in the body.
A bidirectional Mendelian randomization study of the genetic data of close to 295,000 unrelated participants showed the link between the serum 25-hydroxyvitamin D (25[OH]D) and levels of the current standard biomarker for inflammation, C-reactive protein (CRP).
In the non-linear MR analysis, genetically predicted serum 25(OH)D levels had an L-shaped connection with CRP, where CRP levels decreased sharply with increasing 25(OH)D for people within the deficiency range. Further analyses using several complementary methods provided consistent results, confirming the bidirectional relationship between vitamin D and CRP in the deficiency range.
This study suggests that vitamin D deficiency and CRP are directly related and the correction of low vitamin D correction could help in supporting the body’s inflammatory response.