[Micronutrients in oncology. Current data about vitamin D, selenium, L-carnitine and vitamin C].

Many patients receiving cancer treatment use micronutrient supplements, with the intention to complement their cancer treatment, or help them cope with the therapy- and disease-associated side-effects. Up to 90% of the cancer patients are adding antioxidants without the knowledge of the treating physician. There are many concerns that antioxidants might decrease the effectiveness of chemotherapy, but increasing evidence suggests a benefit when antioxidants and other micronutrients, such as selenium, L-carnitine and vitamin D are added to conventional cytotoxic therapies. It is imperative that physicians discuss the use ofantioxidant and other micronutrient supplements with their cancer patients and educate them about potentially negative, but also potentially beneficial effects.