Sunlight is known to improve well-being. The vitamin D that sunlight offers is recognized as a mood booster and a key element in physical health. Vitamin D has also been identified as a regulator for several tissues, including breast and prostate tissue, and has been acknowledged as a key vitamin in improving certain cancers.

Noacea, a US drug company, took this information into account when they created a pill that supplies high levels of calcitriol, a naturally occurring hormone and the biologically active form of vitamin D. This concentrated dose of vitamin D is hoping to be proven as an anti-cancer agent.

The drug is called Asentar (DN-101) and is still being tested, but showed noteworthy results in clinical trials. If successful, it may be offered to those in the advanced stages of prostate cancer. Asentar would be offered as a supplement, not a replacement, to be taken along with chemotherapy treatments, such as Taxotere, a chemotherapy drug also know as docetaxel.

Statistics have shown that prostate cancer is higher among men who are exposed to less sunlight, such as those who live far from the equator. Overall, prostate cancer is the second leading source for cancer death in males. The mortality rate is expected to rise. The Prostate Cancer Foundation expects that without new cures, the number of deaths related to prostate cancer in the US may grow to roughly 68,000 annually by 2025.

During the 250-patient phase two trials, patients who took Asentar with Taxotere typically lived around nine months longer than those who did not supplement with Asentar. That is a 49% increase in overall survival, with most patients living 18 months after being diagnosed. If future tests prove to be as promising, the drug could potentially be available as early as 2009.

The 900-patient phase three trials will seek to prove the safety and survival rates.

There are no guarantees that phase three trials will be as successful as phase two. It has been noted that phase two trials did not use the best possible Taxotere program. Some are arguing that the results may have been exaggerated.

There have also been studies showing that cancer cells lose the capability to react to vitamin D (one of the fat soluble vitamins). In these studies, cancer cells continued to increase, despite large amounts of vitamin D. While the results of clinical tests are still inconclusive, studies are also being done to show if Asentar can help improve the effect of other chemotherapy drugs, such as Taxotere.

There are still many factors involved in determining if Asentar will prove to be useful and safe for those in the advanced stages of prostate cancer, as well as other cancers.