1. Pharmaceuticals                                                                                                                                                                                                                       

• Intermediate: Sodium selenite is used as a selenium supplement in the treatment of selenium deficiency. It can also be used in the preparation of selenium-containing drugs.
• Cancer Research: It has shown potential in cancer treatment research due to its properties as an antioxidant, with studies investigating its ability to inhibit cancer cell growth.

2. Animal Healthcare

• Feed Additive: Sodium selenite is added to animal feed as a source of selenium, which is essential for the proper functioning of animals' immune systems and for preventing certain deficiencies that can affect growth and reproduction.

3. Food & Healthcare Ingredients

•  Fortification: Sodium selenite can be used as a fortifying agent in foods to provide selenium, an essential micronutrient for human health.

4. Personal Care 

• Antioxidant: It is sometimes used in personal care products like skin creams and lotions due to its antioxidant properties. It may also contribute to the health of the skin by preventing damage from oxidative stress.

5. Agrochemicals

• Soil Fertilizer: Sodium selenite can be used as a soil supplement to add selenium, which is crucial for growing crops, particularly in areas where the soil is deficient in selenium.

7. Chemical  Synthesis

• Reagent for Chemical Synthesis: Sodium selenite is sometimes used as a reagent in the synthesis of other selenium compounds and in chemical processes where selenium plays a key role.