Abstract: A nutrient composition or combination of compositions for the treatment or prophylaxis of infections, in particular HIV/AIDS, and for the enhancement of immunity, based on selenium in synergistic combinations with biologically absorbable sources of glutathione, alkalinity enhancing components, a source of sulphur, an anti-mutagenic compound and for oral use, gastrointestinal absorption enhancers. Special uses relate to reducing risks of mother-to-child transmission and treating HIV-positive pregnant women. Preferred further ingredients include anti-inflammatory compounds and nutrients which control homocysteine.