VDR and diabetes mellitus: In another study, genetic analysis showed no significant differences in serum 25(OH)D across VDR genotypes, but TT of rs1544410 or GG of rs731236 increased the risk of microvascular complications of DM by 23%, while 25(OH)D ≥50 nmol/L and major allele homozygotes reduced this risk significantly, suggesting a protective threshold of vitamin D levels that could counteract genetic vulnerability [58].