Abstract: Objective To investigate the association between gut microbiota and vitamin D deficiency, and to identify specific gut microbial taxa related to the risk of vitamin D deficiency. Methods Data from genome-wide association studies (GWAS) on gut microbiota and vitaminD deficiency were summarized and analyzed. Inverse variance weighted (IVW) method was used for Mendelian randomization analysis to assess the causal relationship between gut microbiota taxa and vitamin D deficiency. Sensitivity analyses were conducted to evaluate heterogeneity, pleiotropy, androbustness of the results. Results In the absence of heterogeneity and horizontal pleiotropy, the IVW analysis method that showed Holdemania ( OR = 1. 524, 95 % CI = 1. 001-2. 231, P = 0. 049), Allisonella (OR = 1. 597, 95 % CI = 1. 095-2. 329, P = 0. 015), Escherichia-Shigella (OR = 2. 000, 95 % CI = 1. 156-3. 463, P = 0. 013), and Lachnospiraceae NC2004 group (OR = 2. 106, 95 % CI = 1. 178-3. 766, P = 0. 012) were positively associated with the risk of vitamin D deficiency. While the Lachnospira (OR = 0. 324, 95 % CI = 0. 124-0. 844, P = 0. 021) and Tyzzerella3 (OR = 0. 591, 95 % CI = 0. 406-0. 861, P = 0. 006) were negatively associated with the risk of vitamin D deficiency. Conclusion This study found significant correlations between the abundance of certain specific strains in the gut microbiota and the risk of vitamin D deficiency. This discovery may provide new potential targets for the prevention and treatment of vitamin D deficiency.

Key words: vitamin D deficiency, Mendelian randomization, gut microbiota, causal effects