Oxidative stress is the mechanism by which light radiation (e.g. ultraviolet, UV) has a damaging effect on cells. At the same time, regardless of the data on the negative impact of light radiation and oxidative stress on carcinogenesis, both of these factors are used in the treatment of e.g. skin cancer, breast cancer etc. Photodynamic Therapy (PDT) is a treatment using a combination of light-absorbing photosensitizers and dissolved oxygen to kill cancer. One specific limitation of photodynamic therapy is that the visible light used for photosensitizer excitation has a short tissue penetration depth of several millimeters. This limits the application of PDT to surface cancers in the absence of a technique to illuminate deeper tissue. Efforts to extend tissue depth to which PDTT can be applied have been attempted with use of up-conversion and persistent-luminescent nanoparticles that absorb near infrared light and emit visible light for photosensitizer excitation, yet an initial excitation with an external light source is still required. More recently, systems employing chemiluminescence as an excitation energy source designed to bypass the use of external light have been developed and investigated as potential agents that could overcome the problem of achieving photodynamic therapy in deep tissue. We wish to provide an overview of several systems that have been recently reported that employ both radiative and non-radiative chemiluminescent energy transfer for photosensitizer excitation that have been developed in the hope of achieving “dark” photodynamic therapy. This presentation reviews several of these important new developments in the design of therapeutic systems that utilize chemiluminescence. Thus, oxidative stress causes a condition in which cellular components, including DNA, proteins and lipids, are oxidized and damaged. The anti-tumor effects result from a combination of direct photodamage to tumor cells, destruction of the tumor vasculature, and activation of the immune response. In this review, we will present how Vitamin D affects oxidative stress. The effect of vitamin D administration on the markers of oxidative stress was observed in people with a high-fat diet. High fat diet, is a potent inducer of oxidative stress by altering oxygen metabolism. The topics discussed in this speech will also concern the relationship of Vitamin D with PDT-treated tissue (skin and breast) by enabling accumulation of photosynthetizers. We will present an overview of the published research to date and our own research.