The BCMO1 gene is responsible for the enzyme that converts beta-carotene into the active form of vitamin A that your body needs. SNPs in this gene cause it to not function as well, possibly leaving you deficient in vitamin A.
These two SNPs add together to impair your ability to convert beta-carotene.
People with a T allele on both rs12934922 and rs7501331 have a 69% decreased conversion of beta-carotene to retinol. For people with only a single T in the rs7501331 SNP, the conversion is decreased by 32%. [ref]
Check your genetic data for rs7501331 (23andMe v.4 and v.5, AncestryDNA):
Check your genetic data for rs12934922 (23andMe v.4 and v.5):
Want more details? Check out the full article on the BCMO1 gene.
*SNP stands for Single Nucleotide Polymorphism, which is when one of the nucleotide bases (the A, C, G, or Ts) is replaced by a different nucleotide base in a gene. Want to know more about your genes? Read through all the Snips about SNPs.