Vitamin A (BCMO1)

BCMO1 · rs7501331 + rs12934922

BCMO1 (also called BCO1) converts beta-carotene into retinal. Some common variants have been associated with lower conversion in studies. Genotype alone does not show vitamin A deficiency or an individual's nutritional needs.

Key points

The studied variants are associated with differences in beta-carotene conversion.
Effect sizes depend on the study, dose and population examined.
A marker profile does not replace a measurement of vitamin A status.

#The markers

BCMO1 (beta-carotene-15,15′-monooxygenase, also BCO1) converts beta-carotene into retinal. The missense variants rs12934922 (R267S) and rs7501331 (A379V) have been studied for their effect on enzyme activity; one volunteer study found differences after beta-carotene intake for certain genotypes (Leung 2009). The regulatory marker rs6564851 near the gene was associated with circulating beta-carotene in a GWAS (Lietz 2012). These group-level findings cannot be translated directly into an individual's nutritional needs.

#What it means

A BCMO1 result does not establish deficiency or predict whether a particular diet is sufficient. Vitamin A status depends on several factors and, when needed, is assessed using clinical information and appropriate measurements.

#Context

The BCMO1 effects are well documented functionally and are among the better-understood vitamin genotypes. They describe a predisposition, not a disease. Genome shows the three markers as technical evidence; they are in the built-in panel 'Vitamins A-E'.

What Genome measures. The genotypes at the BCMO1 markers rs12934922 (R267S), rs7501331 (A379V) and the regulatory rs6564851.

Sources

1Leung et al., 2009 Two common SNPs in BCMO1 alter beta-carotene metabolism in female volunteers. FASEB Journal 23:1041-1053. doi.org/10.1096/fj.08-121962
2Lietz et al., 2012 SNPs upstream from BCMO1 influence provitamin A conversion efficiency. Journal of Nutrition 142:161S-165S. doi.org/10.3945/jn.111.140756