Adequate nutritional status is essential to cope with the disease and its treatments. In the market, there are many supplements with varying compositions and qualities some harmless and safe, but others not. Therefore, incorporating additional vitamins, minerals, antioxidants, or other bioactive compounds through the consumption of dietary supplements can cause serious and harmful side effects, as they may interact or interfere with ongoing treatments, reducing their effectiveness or causing unexpected severe toxicities. Hence, it is essential to always consult with the medical team before incorporating such a supplement into the diet.

On the other hand, when nutritional needs cannot be met through regular food intake, the oncologist may prescribe nutritional supplementation with products designed for special dietary needs. These products are specially formulated and developed for the nutritional treatment of patients under medical supervision, thus forming an integral part of the treatment and should be completely distinguished from the aforementioned supplements.