TNFSF11 and osteoporosis: While we did not find any association of selected RANKL SNPs with BMD or PMO in the studied population, it was interesting to note that the CC genotype of rs9533156 (RANKL) was associated with lower 25(OH)D levels in CTRs (p = 0.032), while the heterozygous AG genotype of rs2277438 (RANKL) was associated with lower 25(OH)D in the osteoporosis group (p = 0.02).