The active hormone of VitD (1,25(OH)D3) is very tightly regulated with a life-span of 90-120 minutes at the vitamin D receptor (VDR). Once the hormone binds to the VDR a compensatory process is initiated limiting the lifespan of the hormone.  Transcription of these genes (known as CYP24A1) is responsible for the imminent enzymatic inactivation of 1,25(OH)D3. 

Simply increasing the intake of vitamin D will not affect 1,25(OH)D3 levels because of compensatory CYP24A1 degradation at the VDR. Therefore, a dual-phase process must be used to increase 1,25(OH)D3 at the VDR. StarPower provides the precursor to the active hormone 1,25(OH)D3 and blocks the degradative enzyme CYP24A1 with folic acid. There are no known deleterious side-effects. StarPower is simple, safe and natural.

Interestingly, there is a wealth of data in the literature showing that in various epithelial cancers (breast, lung, colon, prostate) that CYP24A1 plays a major role in the progression of the cancer. In particular, a recent study correlated the severity of colon cancer with the degree of CYP24A1 activity. The more advanced the cancer, the more prevalent was CYP24A1 (Horvath et al, 2010). Furthermore, a recent report found severe overexpression of CYP24A1 in advanced lung cancer tissue (in some cases as much as 50 times normal levels) (Meng et al 2011). These data suggest that as cancers become more aggressive the upregulation of CYP24A1 contributes to the progressive weakening of the anti-cancer properties of VitD. The addition of more VitD is probably ineffective in advanced cancers because any active hormone that's produced is quickly metabolized by the rampant CYP24A1.  Blocking CYP24A1 would seem a logical strategy in the treatment and/or prevention of some cancers. (An interesting experiment would consist of a folic acid regimen combined with vitD in the treatment of cancers where CYP24A1 is upregulated.)

Indeed, there are some tangential data suggesting a role of folate in reduced incidence of colorectal cancer. In particular, higher levels of  folate were correlated with lower reported risk of colorectal cancers during a ten year study period (Stevens, et al., 2011).

Take home message: StarPower contains folic acid to enhance (potentiate) the effect of VitD by prolonging the lifespan of the active hormonal form of VitD. Folic acid blocks the transcription of the genes that encode the synthesis of the enzyme (CYP24A1) that metabolizes/deactivates the active hormone VitD 1,25(OH)D3. StarPower is really quite simple; rather than requiring potentially harmful megadoses of VitD, the combination of VitD + folic acid renders the available VitD more potent by extending its active lifespan. StarPower ensures adequate VitD at the receptor which leads to the correct operation of the immune system.


Horváth, H.C., Lakatos, P., Kósa, J.P., et al. The Candidate Oncogene CYP24A1: A Potential Biomarker for Colorectal Tumorigenesis. J Histochem Cytochem. 2010, 58, 277–285.

Meng, H., Chen, X., Zhang, Z. et al.  Stromal LRP1 in lung adenocarcinoma predicts clinical outcome. Clinical Cancer Research, 2011, 1158, 1078.

 Stevens, V.L., McCullough, M.L., Juzhong, S. High levels of folate from supplements and fortification are not associated with increased risk of colorectal cancer. Gastroenterology, 2011, 141, 98-105