
The Role of B Vitamins in Energy and Immune Support
Helping you understand “why you always feel drained during treatment” — and gentle ways to improve
During cancer treatment — chemotherapy, radiotherapy, or targeted therapy — the body consumes large amounts of energy and nutrients, leaving patients frequently feeling “no matter how much I sleep, I’m still exhausted”, “always low on energy”, and “my immunity is weak”.
The B vitamins (including B1, B2, B3, B5, B6, B7, B9, B12) are core co-factors in energy metabolism and the immune system.
They participate in the conversion of carbohydrates, fats, and proteins; mitochondrial energy production; nerve conduction; and red blood cell formation.
Deficiency directly exacerbates fatigue, brain fog, anaemia, and immune suppression, reducing treatment tolerance.








